Federal Register, Volume 77 Issue 67 (Friday, April 6, 2012)

[Federal Register Volume 77, Number 67 (Friday, April 6, 2012)]
[Rules and Regulations]
[Pages 20948-20986]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-8088]

[[Page 20947]]

Vol. 77

Friday,

No. 67

April 6, 2012

Part III

Department of the Interior

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Fish and Wildlife Service

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50 CFR Part 17

Endangered and Threatened Wildlife and Plants; Listing of the Miami
Blue Butterfly as Endangered Throughout Its Range; Listing of the
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly
in Coastal South and Central Florida; Final Rule

Federal Register / Vol. 77, No. 67 / Friday, April 6, 2012 / Rules
and Regulations

[[Page 20948]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2011-0043; 4500030113]
RIN 1018-AX83

Endangered and Threatened Wildlife and Plants; Listing of the
Miami Blue Butterfly as Endangered Throughout Its Range; Listing of the
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly
in Coastal South and Central Florida

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the Fish and Wildlife Service (Service), are listing the
Miami blue butterfly (Cyclargus thomasi bethunebakeri), as endangered
under the Endangered Species Act of 1973, as amended (Act). We have
determined that designation of critical habitat for the Miami blue
butterfly is not prudent at this time. We also are listing the cassius
blue butterfly (Leptotes cassius theonus), ceraunus blue butterfly
(Hemiargus ceraunus antibubastus), and nickerbean blue butterfly
(Cyclargus ammon) as threatened due to similarity of appearance to the
Miami blue in coastal south and central Florida, and establishing a
special rule under section 4(d) of the Act for these three species.

DATES: This final rule becomes effective on April 6, 2012.

ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/verobeach/. Comments and
materials received, as well as supporting documentation used in the
preparation of this rule, will be available for inspection, by
appointment, during normal business hours at the U.S. Fish and Wildlife
Service, South Florida Ecological Services Office, 1339 20th Street,
Vero Beach, Florida 32960-3559; telephone 772-562-3909; facsimile 772-
562-4288.

FOR FURTHER INFORMATION CONTACT: Larry Williams, Field Supervisor, U.S.
Fish and Wildlife Service, South Florida Ecological Services Office
(see ADDRESSES above). If you use a telecommunications device for the
deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-
877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

This document consists of: (1) A final rule to list the Miami blue
butterfly (Cyclargus thomasi bethunebakeri) as endangered; and (2) a
special rule pursuant to section 4(d) of the Act to list the cassius
blue butterfly (Leptotes cassius theonus), ceraunus blue butterfly
(Hemiargus ceraunus antibubastus), and nickerbean blue butterfly
(Cyclargus ammon) as threatened due to similarity of appearance to the
Miami blue in portions of their ranges.
Why we need to publish a rule. Under the Act, a species or
subspecies may warrant protection through listing if it is endangered
or threatened throughout all or a significant portion of its range. On
August 10, 2011, we published emergency and proposed rules to list the
Miami blue butterfly as endangered. In those documents we explained
that the subspecies currently exists in a fraction of its historical
range and faces numerous threats, and therefore qualifies for listing.
This rule finalizes the protection proposed for the subspecies,
following careful consideration of all comments received during the
public comment period. One of the principal threats to the subspecies
is collection for commercial purposes. For this reason, we are also
prohibiting the collection of the cassius, ceraunus, and nickerbean
blue butterflies, three species which are very similar in appearance to
the Miami blue butterfly, within the historical range of the Miami
blue.
The basis for our action. Under the Act, a species may be
determined to be endangered or threatened based on any of five factors:
(1) Destruction, modification, or curtailment of its habitat or range;
(2) Overutilization; (3) Disease or predation; (4) Inadequate existing
regulations; or (5) Other natural or manmade factors. The Miami blue is
endangered due to four of these five factors. Section 4(e) of the Act
also allows for the extension of protections to similar species under
certain circumstances.
Peer reviewers support our methods. We solicited opinions from
knowledgeable individuals with scientific expertise to review the
technical assumptions, analyses, adherence to regulations, and whether
or not we had used the best available information in our proposed
listing rule for the subspecies. We received 8 peer review responses,
and 2 collaborative responses from State agencies. These peer reviewers
generally concurred with the basis for listing the Miami blue, and
provided additional information, clarifications, and suggestions to
improve this final listing determination.

Acronyms Used in This Document

We use many acronyms throughout this final rule. To assist the
reader, we provide a list of these acronyms here for easy reference:

AME = Allyn Museum of Entomology
BHSP = Bahia Honda State Park
BNP = Biscayne National Park
CCSP = U.S. Climate Change Science Program
CITES = Convention on International Trade in Endangered Species
DJSP = Dagny Johnson Key Largo Hammock Botanical State Park
ENP = Everglades National Park
FCCMC = Florida Coordinating Council on Mosquito Control
FDEP = Florida Department of Environmental Protection
FKMCD = Florida Keys Mosquito Control District
FLMNH = Florida Museum of Natural History
FPS = Florida Park Service
FWC = Florida Fish and Wildlife Conservation Commission
GWHNWR = Great White Heron National Wildlife Refuge
INRMP = Integrated Natural Resource Management Plan
IPCC = Intergovernmental Panel on Climate Change
IRC = Institute for Regional Conservation
KWNWR = Key West National Wildlife Refuge
MIT = Massachusetts Institute of Technology
NABA = North American Butterfly Association
NAS = Naval Air Station Key West
NCSU = North Carolina State University
NEP = nonessential experimental populations
NKDR = National Key Deer Refuge
TNC = The Nature Conservancy
UF = University of Florida
UN = United Nations
USDJ = U.S. Department of Justice
USGS = U.S. Geological Survey

Previous Federal Actions

Federal actions for the Miami blue butterfly prior to August 10,
2011, are outlined in our emergency rule (76 FR 49542), which was
published on that date. Publication of the proposed rule (76 FR 49408),
concurrently published on that date, opened a 60-day comment period,
which closed on October 11, 2011. The emergency rule provides
protection for the Miami blue, ceraunus blue, nickerbean blue, and
cassius blue butterflies for a 240-day period, ending on April 6, 2012.
Because of this time constraint, and the threat of collection of these
species if the emergency rule expires before the proposed rule is
finalized (see Factor B, Overutilization for commercial, recreational,
scientific, or educational purposes), this rule does not have the
standard 30-day period

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before becoming effective. It becomes effective upon the expiration of
the emergency rule, April 6, 2012.

Public Comments

We received comments from the public on the proposed listing
action, including the proposed listing of three similar butterflies due
to similarity of appearance and our determination that designation of
critical habitat is not prudent. In this rule, we respond to these
issues in a single comment section.

Background

The Miami blue is a small, brightly colored butterfly approximately
0.8 to 1.1 inches (1.9 to 2.9 centimeters [cm]) in length (Pyle 1981,
p. 488), with a forewing length of 0.3 to 0.5 inches (8.0 to 12.5
millimeters) (Minno and Emmel 1993, p. 134). Wings of males are blue
above (dorsally), with a narrow black outer border and white fringes;
females are bright blue dorsally, with black borders and an orange/red
and black eyespot near the anal angle of the hindwing (Comstock and
Huntington 1943, p. 98; Minno and Emmel 1993, p. 134). The underside is
grayish, with darker markings outlined with white and bands of white
wedges near the outer margin. The ventral hindwing has two pairs of
eyespots, one of which is capped with red; basal and costal spots on
the hindwing are black and conspicuous (Minno and Emmel 1993, p. 134).
The winter (dry season) form is much lighter blue than the summer (wet
season) form and has narrow black borders (Opler and Krizek 1984, p.
112). Seasonal wing pattern variation may be caused by changes in
humidity, temperature, or length of day (Pyle 1981, p. 489). Miami blue
larvae are bright green with a black head capsule, and pupae vary in
color from black to brown (Minno and Emmel 1993, pp. 134-135).
The Miami blue is similar in appearance to three other sympatric
(occupying the same or overlapping geographic areas, without
interbreeding) butterfly species that occur roughly in the same
habitats: cassius blue (Leptotes cassius theonus), ceraunus blue
(Hemiargus ceraunus antibubastus), and nickerbean blue (Cyclargus
ammon). The Miami blue is slightly larger than the ceraunus blue (Minno
and Emmel 1993, p. 134), and the ceraunus blue has a different ventral
pattern and flies close to the ground in open areas (Minno and Emmel
1994, p. 647). The cassius blue often occurs with the Miami blue, but
has dark bars rather than spots on the undersides of the wings (Minno
and Emmel 1994, p. 647). The Miami blue can be distinguished from the
ceraunus blue and cassius blue by its very broad white ventral
submarginal band, the dorsal turquoise color of both sexes, and the
orange-capped marginal eyespot on the hind wings (Opler and Krizek
1984, p. 112). The nickerbean blue is also similar to the Miami blue in
general appearance but is considerably smaller; it has three black
spots across the basal hindwing, while the Miami blue has four (Calhoun
et al. 2002, p. 15). The larvae and pupae of the nickerbean blue
closely resemble the Miami blue (Calhoun et al. 2002, p. 15).
In a comparison of Miami blue butterfly specimens within the
Florida Museum of Natural History (FLMNH) collection, Saarinen (2009,
pp. 42-43) found a significant difference in forewing length between
males and females, with males having shorter forewings than females.
However, no significant differences were found between forewing length
in comparing wet and dry seasons, decade of collection, seven different
regions, or between eastern mainland and Keys specimens (Saarinen 2009,
pp. 42-43). No seasonal size differences were found between the
mainland populations and those in the Keys (Saarinen 2009, p. 43).
In a comparison of body size in a recent Miami blue population,
females were significantly larger than males, and individuals sampled
in the wet season were also significantly larger than in the dry season
(Saarinen 2009, p. 43). In a comparison of recent Bahia Honda State
Park (BHSP) individuals with specimens from historical collections
(FLMNH data), BHSP individuals were significantly larger than
historical specimens, females from BHSP were significantly larger than
historical female specimens, and BHSP adults measured in wet seasons
were larger than those sampled in wet seasons in museum collections
(Saarinen 2009, p. 43). Saarinen (2009, p. 47) suggested that perhaps
larger adults were selected for over time with larger adults being more
capable of dispersing and finding food and mates. Limited food
resources during larval development or abrupt termination of
availability of food in the last larval instar can lead to early
pupation and a smaller adult size (T.C. Emmel, pers. comm., as cited in
Saarinen 2009, p. 47). It is possible that differences in host plant
(e.g., nutrition) and age of specimens (e.g., freshness) may also be
factors when comparing body size between recent specimens and those
from historical collections.

Taxonomy

The Miami blue belongs to the family Lycaenidae (Leach), subfamily
Polyommatinae (Swainson). The species Hemiargus thomasi was originally
described by Clench (1941, pp. 407-408), and the subspecies Hemiargus
thomasi bethunebakeri was first described by Comstock and Huntington
(1943, p. 97). Although some authors continue to use Hemiargus, Nabokov
(1945, p. 14) instituted Cyclargus for some species, which has been
supported by more recent research (Johnson and Balint 1995, pp. 1-3, 8-
11, 13; Calhoun et al. 2002, p. 13; K. Johnson, Florida State
Collection of Arthropods, in litt. 2002). There are differences in the
internal genitalic structures of the genera Hemiargus and Cyclargus
(Johnson and Balint 1995, pp. 2-3, 11; K. Johnson, in litt. 2002). Kurt
Johnson (in litt. 2002), who has published most of the existing
literature since 1950 on the blue butterflies of the tribe
Polyommatini, reaffirmed that thomasi belongs in the genus Cyclargus
(Nabokov 1945, p. 14), not Hemiargus. Accordingly, Cyclargus thomasi
bethunebakeri (Pelham 2008, p. 21) and its taxonomic standing is
accepted (Integrated Taxonomic Information System 2011, p. 1).
In 2003, questions about the taxonomic identity of Miami blues from
BHSP were raised by a few individuals. To address these questions, the
Service sent two pairs (male and female) of adult specimens to three
independent taxonomists and reviewers (Dr. Jacqueline Miller, Associate
Curator, Allyn Museum of Entomology (AME), FLMNH; Dr. Paul Opler,
Colorado State University; and John Calhoun, Museum of Entomology,
Florida State Collection of Arthropods) for verification. To avoid harm
to the wild population, scientists examined moribund adults from a
captive colony generated from individuals taken from BHSP. Each
reviewer independently confirmed through various means (e.g.,
comparison with confirmed specimens, dissection and examination of
genitalia) that the identities of the adult specimens examined were
Cyclargus thomasi bethunebakeri (J. Miller, in litt. 2003; P. Opler, in
litt. 2003; J. Calhoun, in litt. 2003a). We received an additional
confirmation from Lee Miller, Curator (AME, FLMNH), stating that the
identities of the adult specimens examined were Cyclargus thomasi
bethunebakeri (L. Miller, in litt. 2003). Taxonomic verification by
genitalic dissection of the Miami blue at Key West National Wildlife
Refuge (KWNWR) has not occurred, but preliminary molecular evidence has
confirmed that they are the same taxon (E.V. Saarinen, unpub. data, as
cited in

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Saarinen 2009, p. 18; E. Saarinen, in litt. 2011).

Life History

Like all butterflies, the Miami blue undergoes complete
metamorphosis, with four life stages (egg, caterpillar or larva, pupa
or chrysalis, and adult). The generation time is approximately 30-40
days (Carroll and Loye 2006, p. 19; Saarinen 2009, pp. 22, 76) and
similar for both males and females (Trager and Daniels 2011, p. 35).
Although a single Miami blue female can lay 300 eggs, high mortality
may occur in the immature larval stages prior to adulthood (T. Emmel,
University of Florida [UF], pers. comm. 2002). Trager and Daniels
(2011, p. 40) indicated that larger, longer-lived females demonstrate a
higher fecundity. Reported host plants are blackbead (Pithecellobium
spp.), nickerbean (Caesalpinia spp.), balloonvine (Cardiospermum spp.),
and presumably Acacia spp. (Kimball 1965, p. 49; Lenczewski 1980, p.
47; Pyle 1981, p. 489; Opler and Krizek 1984, p. 113; Minno and Emmel
1993, p. 134; Calhoun et al. 2002, p. 18; Cannon et al. 2010, p. 851).
In addition, Rutkowski (1971, p. 137) observed a female laying one egg
just above the lateral bud on snowberry (Chiococca alba). Eggs are laid
singly near the base of young pods or just above the lateral buds of
balloonvine and the flowers of leguminous trees (Opler and Krizek 1984,
p. 113; Minno and Emmel 1993, p. 134); flower buds and young tender
leaves of legumes are preferred laying sites (Minno and Minno 2009, p.
78; M. Minno, pers. comm. 2010).
On nickerbean plants (Caesalpinia spp.), females lay eggs on
developing shoots, foliage, and flower buds (Saarinen 2009, p. 22;
Trager and Daniels 2011, p. 35). Oviposition occurs throughout the day
with females often seeking terminal growth close to the ground (<3.3
feet [<1 meter]) or in locations sheltered from the wind (Emmel and
Daniels 2004, p. 13). Eggs are generally laid singly, but may be
clustered on developing leaves, shoot tips, and flower buds (Saarinen
2009, p. 22). After several days of development, larvae chew out of
eggs and develop through four instar stages, with total larval
development time lasting 3 to 4 weeks, depending upon temperature and
humidity (Saarinen 2009, p. 22). Fourth instar larvae pupate in
sheltered or inconspicuous areas, often underneath leaf whorls or
bracts (Saarinen 2009, p. 22). Adult butterflies eclose (emerge) after
5 to 8 days, depending on temperature and humidity (Saarinen 2009, p.
22).
On blackbead plants, females lay eggs on flower buds and emerging
leaves (Cannon et al. 2010, p. 851; Trager and Daniels 2011, p. 35).
Oviposition on, or larval consumption of, mature blackbead leaves was
not observed (Cannon et al. 2010, p. 851). Thus, Cannon et al. (2010,
p. 851) suggested that abundance may be limited by the availability of
young blackbead leaves and buds for egg-laying, even if abundant
suitable nectar sources (see Habitat) are available year-round.
On balloonvine, females lay single eggs near fruit (capsules)
(Carroll and Loye 2006, p. 18). Newly hatched larvae chew distinctive
holes through the outer walls of the capsules to access seeds (Minno
and Emmel 1993, p. 134). After consuming seeds within the natal
capsule, larvae must crawl to a sequence of two or three balloons
before growing large enough to pupate. Attending ants follow through
the same holes (see Interspecific relationships below). Miami blues
were also observed to commonly pupate within mature capsules (sometimes
with ants in attendance within the capsule) (Carroll and Loye 2006, p.
20).
The Miami blue has been described as having multiple, overlapping
broods year-round (Pyle 1981, p. 489). Adults can be found every month
of the year (Opler and Krizek 1984, pp. 112-113; Minno and Emmel 1993,
p. 135; 1994, p. 647; Emmel and Daniels 2004, p. 9; Saarinen 2009, p.
22). Opler and Krizek (1984, pp. 112-113) indicated one long winter
generation from December to April, during which time the adults are
probably in reproductive diapause (a period in which growth,
development, and physiological activity is suspended or diminished); a
succession of shorter generations was thought to occur from May through
November, the exact number of which is unknown. Glassberg et al. (2000,
p. 79) described the Miami blue as having occurred all year, with three
or more broods. Researchers have noted a marked decrease of adults from
December to early February at BHSP, indicative of a short diapause
(Emmel and Daniels 2003, p. 3; 2004, p. 9). Saarinen also noted that
the life cycle at BHSP slowed in winter months and suspected a slight
diapause (E.V. Saarinen and J.C. Daniels, unpub. data, as cited in
Saarinen 2009, p. 22). Conversely, Minno (pers. comm. 2010) noted that
there have been records of adults in December and January and suggested
that this tropical butterfly may not have a winter diapause, but
rather, emergence may be delayed by cold temperatures in some years.
Salvato and Salvato (2007, p. 163) and Cannon et al. (2010, pp. 849-
850) also reported numerous adults at BHSP and KWNWR, respectively,
during winter months.
Information on adult lifespan is limited. Based on field studies,
adult Miami blues have been found to live 9 days, but most adults are
thought to live only a few days (J. Daniels, UF, pers. comm. 2003a,
2003b). In general, adults may survive less than a week in the wild;
there are approximately 8-10 generations per year (Saarinen et al.
2009a, p. 31). Generations are not completely discrete due to the
variance in development time of all life stages (Saarinen et al. 2009a,
p. 31). Adult longevity is not well understood. Some lycaenids have the
ability to survive longer than mark-recapture studies indicate (Johnson
et al. 2011, p. 8). For example, the Palos Verdes blue (Glaucopsyche
lygdamus palosverdesensis), thought to live 10 days or less in the
field, has been documented to have a life span of up to 38 days in the
laboratory (T. Longcore, University of California, in litt. 2011;
Johnson et al. 2011, p. 8). Additional field studies are needed to
better ascertain adult Miami blue longevity in the wild.
Range size and dispersal--At this time, it is unclear how far adult
Miami blues can disperse and the mechanisms for dispersal (i.e., active
[flight] or passive [wind-assisted]). Initial mark-recapture studies of
the butterfly indicate they are nonmigratory and appear to be sedentary
(Emmel and Daniels 2004, p. 6). Based on mark-recapture work conducted
in 2002-2003, recaptured adults (N=39) moved an average of 6.53 +/-
11.68 feet (2.0 +/-3.6 meters), four individuals moved between 25 and
50 feet (7.6 and 15.2 meters), and only three individuals moved more
than 50 feet (15.2 meters) over a few days (Emmel and Daniels 2004, pp.
6, 32-38). Few individuals were found to move between the lower and
upper walkway locations of the south end colony sites at BHSP
(approximately 100 feet [30.5 meters]); no movement between any of the
smaller individual, isolated colony sites was recorded (Emmel and
Daniels 2004, p. 6). However, Saarinen (2009, pp. 73, 78-79) found that
genetic exchange between colonies occurred at BHSP and noted that small
habitat patches may be crucial in providing links between
subpopulations in an area.
Interspecific relationships--As in many lycaenids worldwide (Pierce
et al. 2002, p. 734), Miami blue larvae associate with ants (Emmel
1991, p. 13; Minno and Emmel 1993, p. 135; Carroll and Loye 2006, pp.
19-20; Trager and Daniels 2011, p. 35) in at least four

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genera of ants in three subfamilies of Formicidae (Saarinen and Daniels
2006, p. 71; Saarinen 2009, pp. 131, 133). Miami blues using nickerbean
at BHSP and Everglades National Park (ENP) (reintroduced individuals)
were variously tended by Camponotus floridanus, C. planatus,
Crematogaster ashmeadi, Forelius pruinosus, and Tapinoma melanocephalum
(Saarinen and Daniels 2006, p. 71; Saarinen 2009, pp. 131, 138). C.
floridanus was the primary ant symbiont, commonly found tending larvae;
other ant species were encountered less often (Saarinen and Daniels
2006, p. 70; Saarinen 2009, pp. 131-132). Liquid (honeydew) exuded from
the butterfly's dorsal nectary organ (honey gland) was actively imbibed
by all species of ants (Saarinen and Daniels 2006, p. 70; Saarinen
2009, p. 132).
Late Miami blue instars were always found in association with ants,
but early instars, prepupae, and pupae were frequently found without
ants present (Saarinen and Daniels 2006, p. 70). Forelius pruinosus and
Tapinoma melanocephalum were observed to derive honeydew from Miami
blues they tended, but were not observed to actively protect them from
any predator (Saarinen and Daniels 2006, p. 71; Saarinen 2009, p. 133).
However, the presence of ants in the vicinity of larvae may potentially
deter predators (Saarinen and Daniels 2006, pp. 71, 73; Saarinen 2009,
p. 133; Trager and Daniels 2009, p. 480). Two additional ants,
Paratrechina longicornis and P. bourbonica, have been identified as
potential associates of the Miami blue (Saarinen and Daniels 2006, pp.
70-71; Saarinen 2009, pp. 131, 138). P. longicornis was found near
Miami blue larvae and appeared to tend them during brief encounters; P.
bourbonica tended another lycaenid, martial scrub-hairstreak (Strymon
martialis) at BHSP (Saarinen and Daniels 2006, p. 70). Cannon et al.
(2007, p. 16) also observed two ant species attending Miami blues on
KWNWR. Based on photographs, the ants appeared to be Camponotus
inaequalis and P. longicornis. C. planatus was observed on blackbead.
In the 1980s, Miami blue larvae that fed on balloonvine in the
upper Keys were also tended by ants (Camponotus floridanus and C.
planatus) (Carroll and Loye 2006, pp. 19-20). Carroll and Loye (2006,
p. 20) found that Camponotus spp. raised with Miami blue larvae lived
longer than ants raised with larvae of other lycaenid species or
without any food source, demonstrating that larval secretions benefit
ants.
More recently, Trager and Daniels (2009, p. 479) most commonly
found Camponotus floridanus and C. planatus associated with wild and
recently released Miami blue larvae. In a comparison of Miami blue
larvae raised with and without ants, no effect of ant presence was
found on any measurements of larval performance (e.g., age at pupation,
pupal mass, length of pupation, total time as an immature) (Trager and
Daniels 2009, p. 480). Miami blue larval development was found to be
similar to that of other conspecific lycaenid species not tended by
ants (Trager and Daniels 2009, p. 480). Although the relationships are
not completely understood, it appears that Miami blue larvae may
receive some benefits from tending ants (e.g., potential defense from
predators) without much, if any, costs incurred.

Habitat

The Miami blue is a coastal butterfly reported to occur in openings
and around the edges of hardwood hammocks (forest habitats
characterized by broad-leaved evergreens), and in other communities
adjacent to the coast that are prone to frequent natural disturbances
(e.g., coastal berm hammocks, dunes, and scrub) (Opler and Krizek 1984,
p. 112; Minno and Emmel 1994, p. 647; Emmel and Daniels 2004, p. 12).
It also has been reported to use tropical pinelands (Minno and Emmel
1993, p. 134) and open sunny areas along trails (Pyle 1981, p. 489). In
the Keys, it was most abundant near disturbed hammocks where weedy
flowers provided nectar (Minno and Emmel 1994, p. 647). It also
occurred in pine rocklands (fire-dependent slash pine community with
palms and a grassy understory) on Big Pine Key (Minno and Emmel 1993,
p. 134; Calhoun et al. 2002, p. 18) and elsewhere in Monroe and Miami-
Dade Counties. In Miami-Dade County, it occurred locally inland,
sometimes in abundance (M. Minno, pers. comm. 2010). Within KWNWR, all
occupied areas had coastal strands and dunes fronted by beaches (Cannon
et al. 2007, p. 13; Cannon et al. 2010, p. 851).
Larval host plants include blackbead, nickerbean, balloonvine, and
presumably Acacia spp. (Dyar 1900, pp. 448-449, Kimball 1965, p. 49;
Lenczewski 1980, p. 47; Pyle 1981, p. 489; Calhoun et al. 2002, p. 18).
Gray nickerbean (Caesalpinia bonduc) is widespread and common in
coastal south Florida. Following disturbances, it can dominate large
areas (K. Bradley, The Institute for Regional Conservation [IRC], pers.
comm. 2002). Gray nickerbean has been recorded as far north as Volusia
County on the east coast, matching the historical range of the Miami
blue, and Levy County on the west coast (J. Calhoun, pers. comm.
2003b). The Miami blue is also reported to use peacock flower
(Caesalpinia pulcherrima) (Matteson 1930, pp. 13-14; Calhoun et al.
2002, p. 18), a widely cultivated exotic that occurs in disturbed
uplands and gardens (Gann et al. 2001-2012, p. 1). Rutkowski (1971, p.
137) and Opler and Krizek (1984, p. 113) reported the use of snowberry.
Brewer (1982, p. 22) reported the use of cat's paw blackbead
(Pithecellobium unguis-cati) on Sanibel Island in Lee County.
Prior to the 1970s, documented host plants for the butterfly were
nickerbean and blackbead (J. Calhoun, pers. comm. 2003b). Balloonvine
(Cardiospermum spp.) was not reported as a host plant until the 1970s,
when these plants seemed to have become common in extreme southern
Florida (J. Calhoun, pers. comm. 2003b). Subsequently, balloonvine
(Cardiospermum halicacabum), an exotic species in Florida, was the most
frequently reported host plant for Miami blue (e.g., Lenczewski 1980,
p. 47; Opler and Krizek 1984, p. 113; Minno and Emmel 1993, p. 134;
1994, p. 647; Calhoun et al. 2002, p. 18). However, Carroll and Loye
(2006, pp. 13-15) corrected ``the common view that a principal host
plant, balloonvine, is an exotic weed.'' They found that published
reports of Miami blue larvae on balloonvine all identified the host as
C. halicacabum and stated that the butterfly was instead dependent upon
a declining native, C. corindum (Carroll and Loye 2006, pp. 14, 23).
Bradley (pers. comm. 2002) also confirmed that C. halicacabum does not
occur in the Keys, noting that the native balloonvine (C. corindum) is
relatively common and widespread in the Keys and has been commonly
mistaken as C. halicacabum in the Keys and other sites in south
Florida.
Calhoun (pers. comm. 2003b) suggested that the Miami blue may
simply utilize whatever acceptable hosts are available under suitable
conditions. According to Calhoun (pers. comm. 2003b), a review of the
historical range of the butterfly and its host plants suggests
balloonvine was a more recent larval host plant and temporarily
surpassed nickerbean as the primary host plant. As native coastal
habitats were destroyed, balloonvine readily invaded disturbed
environments, and the Miami blue used what was most commonly available.
Minno (pers. comm. 2010) suggested that the Miami blue used balloonvine
on Key Largo and Plantation Key extensively in the 1970s through the
1990s, noting that nickerbean, blackbead, and perhaps

[[Page 20952]]

other hosts were also probably used, but not documented.
The Miami blue metapopulation (series of small populations that
have some level of interaction) at KWNWR was found to rely upon Florida
Keys blackbead as the singular host plant (Cannon et al. 2007, p. 1;
Cannon et al. 2010, pp. 851-852). Blackbead was also an important
nectar plant when in flower. High counts of Miami blues at KWNWR were
generally associated with the emergence of flowers and new leaves on
blackbead (Cannon et al. 2007, pp. 14-15; Cannon et al. 2010, pp. 851-
852). All sites that supported Miami blues contained blackbead (Cannon
et al. 2007, p. 6; Cannon et al. 2010, p. 851). Limited abundance of
blackbead within select areas of KWNWR was thought to limit abundance
of the Miami blue (Cannon et al. 2007, p. 10; Cannon et al. 2010, p.
850). At BHSP, the Miami blue was closely associated with gray
nickerbean, but also used blackbead (M. Minno, pers. comm. 2010). In
KWNWR, gray nickerbean was rare, with only a few small plants on Boca
Grande Key and the Marquesas Keys (Cannon et al. 2010, p. 851).
Adult Miami blues have been reported to feed on a wide variety of
nectar sources, including Spanish needles (Bidens alba), Leavenworth's
tickseed (Coreopsis leavenworthi), scorpionstail (Heliotropium
angiospermum), turkey tangle fogfruit or capeweed (Lippia nodiflora),
buttonsage (Lantana involucrata), snow squarestem (Melanthera nivea [M.
aspera]), blackbead, Brazilian pepper (Schinus terebinthifolius), false
buttonweed (Spermacoce spp.), and seaside heliotrope (Heliotropium
curassavicum) (Pyle 1981, p. 489; Opler and Krizek 1984, p. 113; Minno
and Emmel 1993, p. 135; Emmel and Daniels 2004, p. 12). Emmel and
Daniels (2004, p. 12) reported that the Miami blue uses a variety of
flowering plant species in the Boraginaceae, Asteraceae, Fabaceae,
Polygonaceae, and Verbenaceae families for nectar. Cannon et al. (2010,
p. 851) found the butterfly uses nine plant species as nectar sources
within KWNWR, including: blackbead, snow squarestem, coastal searocket
(Cakile lanceolata), black torch (Erithalis fruticosa), yellow joyweed
(Alternanthera flavescens), bay cedar (Suriana maritime), sea lavender
(Argusia gnaphalodes), seaside heliotrope, and sea purslane (Sesuvium
portulacastrum).
Nectar sources must be near potential host plants since the
butterflies are presumably sedentary and may not travel between patches
of host and nectar sources (Emmel and Daniels 2004, p. 13). This may
help explain the absence of the Miami blue from areas in which host
plants are abundant and nectar sources are limited (J. Calhoun, pers.
comm. 2003b). Emmel and Daniels (2004, p. 13) argued that it is
potentially critical that sufficient available adult nectar sources be
directly adjacent to host patches and also important that a range of
potential nectar sources be available in the event one plant species
goes out of flower or is adversely impacted by environmental factors.
Cannon et al. (2010, p. 851) suggested that the growth stage of
blackbead, coupled with abundant nectar from herbaceous plants, likely
influenced Miami blue abundance; the highest counts occurred when
blackbead was flowering profusely and producing new leaves.

Historical Distribution

The Miami blue butterfly (Cyclargus thomasi bethunebakeri) is
endemic to Florida with additional subspecies occurring in the
Caribbean (Smith et al. 1994, p. 129; Hernandez 2004, p. 100; Saarinen
2009, pp. 18-19, 28). Field guides and other sources differ as to
whether C. thomasi bethunebakeri occurs in the Bahamas. Clench (1963,
p. 250), who collected butterflies in the West Indies, indicated that
the subspecies occurred only in Florida. Riley (1975, p. 110) and
Calhoun et al. (2002, p. 13) indicated that the Miami blue of Florida
rarely occurs as a stray in the Bahamas. Minno and Emmel (1993, p. 134;
1994, p. 647) and Calhoun (1997, p. 46) considered the Miami blue to
occur only in Florida (endemic to Florida, with other subspecies found
in the Bahamas and Greater Antilles). Smith et al. (1994, p. 129)
indicated that the Miami blue occurs in southern Florida, but noted it
has been recorded from the Bimini Islands in the Bahamas. However, in a
recent comprehensive study of museum specimens, Saarinen (2009, p. 28)
found no specimens in current museum holdings to verify this. Overall,
the majority of historical records pertaining to this subspecies'
distribution are dominated by Florida occurrences, with any peripheral
occurrences in the Bahamas possibly being ephemeral in nature.
Although information on distribution is somewhat limited, it is
clear that the historical range of the Miami blue has been
significantly reduced. The type series (i.e., the original set of
specimens on which the description of the species is based) contains
specimens ranging from Key West up the east coast to Volusia County
(Comstock and Huntington 1943, p. 98; J. Calhoun, pers. comm., 2003b).
Opler and Krizek (1984, p. 112) showed its historical range as being
approximately from Tampa Bay and Cape Canaveral southward along the
coasts and through the Keys. It has also been collected in the Dry
Tortugas (Forbes 1941, pp. 147-148; Kimball 1965, p. 49; Glassberg and
Salvato 2000, p. 2). Lenczewski (1980, p. 47) noted that it was
reported as extremely common in the Miami area in the 1930s and 1940s.
Calhoun et al. (2002, p. 17) placed the historical limits of the
subspecies' northern distribution at Hillsborough and Volusia Counties,
extending southward along the coasts to the Marquesas Keys (west of Key
West).
The Miami blue was most common on the southern mainland and the
Keys, especially Key Largo and Big Pine Key (Calhoun et al. 2002, p.
17) and other larger keys with hardwood hammock (Monroe County) (M.
Minno, pers. comm. 2010). The subspecies was recorded on at least 10
islands of the Keys (Adams Key, Big Pine Key, Elliott Key, Geiger Key,
Key Largo, Lignumvitae Key, Old Rhodes Key, Plantation Key, Stock
Island, Sugarloaf Key) (Minno and Emmel 1993, p. 134). On the Gulf
coast, it was reportedly more localized and tended to occur on more
southerly barrier islands (J. Calhoun, pers. comm. 2003b). According to
Calhoun et al. (2002, p. 17), the Miami blue occupied areas on the
barrier islands of Sanibel, Marco, and Chokoloskee, along the west
coast into the 1980s (based upon Brewer 1982, p. 22; Minno and Emmel
1994, pp. 647-648). Lenczewski (1980, p. 47) reported that the Miami
blue historically occurred at Chokoloskee, Royal Palm (Miami-Dade
County), and Flamingo (Monroe County) within ENP, but that the
subspecies has not been observed in ENP since 1972.
Based upon examination of specimens from museum collections (N =
689), Saarinen (2009, pp. 42, 55-57) found a large, primarily coastal,
geographic distribution for the butterfly. Most specimens from an 11-
county area from 1900 to 1990 were collected in Miami-Dade and Monroe
Counties (Saarinen 2009, pp. 42, 58). Records from Miami-Dade County (N
= 212) were most numerous in the 1930s and 1940s; records from Monroe
County (N = 387) (including all of the Florida Keys) were most numerous
in the 1970s (Saarinen 2009, pp. 42, 58). Saarinen (2009, p. 47) was
not able to quantify issues of collector bias and noted that collecting
restrictions, inaccessibility of certain islands, and targeted interest
in certain areas may have been factors influencing the relative
abundance (and distribution) of specimens collected. For example, it is
unclear whether Key

[[Page 20953]]

Largo represented a ``central hotspot,'' a spot simply heavily visited
by lepidopterists, or both (Saarinen 2009, p. 47). Still, it is clear
that specimens were common in museum collections from the early 1900s
to the 1980s, suggesting that the butterfly was abundant, at least in
local patches, during this time period (Saarinen 2009, p. 46). This is
consistent with the work of Carroll and Loye (2006, pp. 15-18), who, in
a compilation of location data for specimens (N = 209), found that most
collections were from the Upper Keys; those from peripheral sites were
generally less recent and only single specimens. Examination of museum
records further verified the Miami blue's wide distribution in southern
Florida through time (Carroll and Loye 2006, pp. 15-18; Saarinen 2009,
p. 46).
By the 1990s, very few Miami blue populations were known to
persist, and the butterfly had not been seen on the western Florida
coast since 1990, where it was last recorded on Sanibel Island (Calhoun
et al. 2002, p. 17). One of the few verifiable reports (prior to
rediscovery in 1999) was on Big Pine Key in March 1992 (Glassberg et
al. 2000, p. 79; Glassberg and Salvato 2000, p. 1; Calhoun et al. 2002,
p. 17). Following Hurricane Andrew in 1992, there were a few
unsupported reports from Key Largo and Big Pine Key and the
southeastern Florida mainland from approximately 1993 to 1998
(Glassberg and Salvato 2000, p. 3; Calhoun et al. 2002, p. 17). In
1996, four adult Miami blues were observed in the area of Dagny Johnson
Key Largo Hammock Botanical State Park (DJSP) by Linda and Byrum Cooper
(L. Cooper, listowner of LEPSrUS Web site, pers. comm. 2002; Calhoun et
al. 2002, p. 17). However, a habitat restoration project apparently
eradicated that population (L. Cooper, pers. comm. as cited in Calhoun
et al. 2002, p. 17).
The Miami blue was presumed to be extirpated until its rediscovery
in 1999 by Jane Ruffin, who observed approximately 50 individuals at a
site in the lower Keys (Bahia Honda) (Ruffin and Glassberg 2000, p. 3;
Calhoun et al. 2002, p. 17). Additional individuals were located at a
site within 0.5 mile (mi) (0.8 kilometers (km)) of where Ruffin had
discovered the population (Glassberg and Salvato 2000, p. 3). Glassberg
and Salvato (2000, p. 1) stated that more than 15 highly competent
butterfly enthusiasts had failed to find any populations of the Miami
blue from 1992 until 1999, despite more than 1,000 hours of search
effort in all sites known to harbor former colonies and other potential
sites throughout south Florida and the Keys. In May 2001, there was an
additional sighting by Richard Gillmore of a single Miami blue in the
hammocks in North Key Largo (Calhoun et al. 2002, p. 17; J. Calhoun,
pers. comm. 2003b).

Current Distribution

Numerous searches for the Miami blue have occurred in the past
decade by various parties. The Miami blue was not observed on 105
survey dates at 11 locations on the southern Florida mainland from 1990
to 2002 (Edwards and Glassberg 2002, p. 4). In the Keys, surveys during
the same time period also produced no sightings of the Miami blue at 29
locations for 224 survey dates (Edwards and Glassberg 2002, p. 4). In
2002, the Service initiated a status survey, contracting researchers at
the UF, to search areas within the subspecies' historical range,
concentrating on the extreme south Florida mainland and throughout the
Keys. Despite surveys at 45 sites during 2002-2003, adults or immature
stages were found only at a single site near BHSP on West Summerland
Key (Emmel and Daniels 2004, pp. 3-6; 21-25) (approximately 1.9 mi [3
km]) west of BHSP). The Miami blue was not found on the mainland,
including Fakahatchee Strand, Charles Deering Estate, ENP, Marco
Island, or Chokoloskee (Emmel and Daniels 2004, pp. 5-6, 25). It was
also absent from the following locations in the Keys: Elliott, Old
Rhodes, Totten, and Adams Key in Biscayne National Park (BNP) and Key
Largo and Plantation Key in the Upper Keys; Lignumvitae, Lower
Matecumbe, Indian, and Long Keys in the Middle Keys; and Little Duck,
Missouri, Ohio, No Name, Big Pine, Ramrod, Little Torch, Wahoo, Cudjoe,
Sugarloaf, and Stock Island in the Lower Keys (Emmel and Daniels 2004,
pp. 3-5; 21-24).
Based upon an additional independent survey in 2002, the Miami blue
was also not found at 18 historical locations where it had previously
been observed or collected in Monroe, Broward, Miami-Dade, and Collier
Counties into the 1980s (D. Fine, unpub. data, pers. comm. 2002). These
were: Cactus Hammock (Big Pine Key), County Road (Big Pine Key), Grassy
Key, John Pennekamp Coral Reef State Park (Key Largo), Windley Key,
Crawl Key, Stock Island, Plantation Key, and Lower Matecumbe Key in
Monroe County; Hugh Taylor Birch State Park and Coral Springs (2
locations) in Broward County; Redlands, Frog City, Card Sound Road, and
an unidentified road in Miami-Dade County; and Marco Island and
Fakahatchee Strand State Preserve in Collier County.
In 2003, the Service contracted the North American Butterfly
Association (NABA) to perform systematic surveys in south Florida and
the Keys to identify all sites at which 21 targeted butterflies,
including the Miami blue, could be found. Despite considerable survey
effort (i.e., 187 surveys performed), the Miami blue was not located at
any location except BHSP (NABA 2005, pp. 1-7). In addition, the Miami
blue was not present within the J.N. Ding Darling National Wildlife
Refuge or on Sanibel-Captiva Conservation Foundation properties (both
on Sanibel Island), during annual surveys conducted from 1998 to 2009
(M. Salvato, pers. comm. 2011a). Monthly or quarterly surveys of Big
Pine Key, conducted from 1997 to 2010, failed to locate Miami blues (M.
Salvato, pers. comm. 2011b). Minno and Minno (2009, pp. 77, 123-193)
failed to locate the subspecies during butterfly surveys throughout the
Keys conducted from August 2006 to July 2009.
Although two fourth-instar larvae were documented on West
Summerland Key in November 2003, on unprotected land approximately 2.2
mi (3.6 km) west of BHSP (Emmel and Daniels 2004, pp. 3, 24, 26), none
have been seen there since. According to Daniels (pers. comm. 2003c),
an adult (or adults) was likely blown to this key from BHSP by strong
winds or was at least partially assisted by the wind.
In November 2006, Miami blues were discovered on islands within
KWNWR (Cannon et al. 2007, p. 2). This discovery was significant
because it was a new, geographically separate population, and doubled
the known number of metapopulations remaining (to 2). During the period
from 1999 to 2009, the Miami blue was consistently found at BHSP
(Ruffin and Glassberg 2000, p. 29; Edwards and Glassberg 2002, p. 9;
Emmel and Daniels 2009, p. 4; Daniels 2009, p. 3). However, this
population may now be extirpated. Thus, islands of KWNWR appear to
support the only known extant population.
Overall, the Miami blue has undergone a substantial reduction in
its historical range, with an estimated >99 percent decline in area
occupied (Florida Fish and Wildlife Conservation Commission [FWC] 2010,
p. 11). In 2009, metapopulations existed at two main locations: BHSP
and KWNWR, roughly 50 mi (80 km) apart. The metapopulation at BHSP is
now possibly extirpated with the last adult documented in July 2010 (A.
Edwards, Florida Atlantic University, pers. comm. 2011). It is feasible
that additional occurrences exist in the Keys, but these may be
ephemeral and low in

[[Page 20954]]

population number (Saarinen 2009, p. 143). In 2010, the Service funded
an additional study with UF to search remote areas for possible
presence; this study has not identified any new populations. The
subspecies was not located in limited surveys conducted in the Cape
Sable area of ENP in March 2011 (P. Halupa, pers. obs. 2011; M. Minno,
pers. comm. 2011a) nor December 2011 (J. Daniels, pers. comm. 2011).

Bahia Honda State Park

BHSP is a small island at the east end of the lower Keys,
approximately 7.0 mi (11.3 km) west of Vaca Key (Marathon) and 2.0 mi
(3.2 km) east of Big Pine Key. The amount of suitable habitat (habitat
supporting larval host plants and adjacent adult nectar sources) within
BHSP is approximately 1.5 acres (ac) (0.6 hectares [ha]). Of the
suitable habitat available at BHSP, approximately 85 percent (1.3 ac
[0.5 ha]) was occupied by the Miami blue (Emmel and Daniels 2004, p.
12). The metapopulation comprised 13 distinct colonies, with the core
comprising 3 or 4 colonies, located at the southwestern end (Emmel and
Daniels 2004, pp. 6, 27). This area contained the largest contiguous
patch of host plants, although the size was estimated to be 0.8 ac
(0.32 ha) (Emmel and Daniels 2004, p. 12). The second largest colony
occurred at the opposite (northeast) end of BHSP and was based solely
on the presence of two to three small, isolated patches of nickerbean
directly adjacent to an existing nature trail and parking area (Emmel
and Daniels 2004, p. 6). The remaining colonies were isolated, with
most occurring in close proximity to the main park road (Emmel and
Daniels 2004, pp. 13, 27). Isolated colonies used very small patches of
nickerbean (e.g., one was estimated to be 10 by 10 feet [3 by 3
meters]) (Emmel and Daniels 2003, p. 3), often adjacent to paved roads
(Emmel and Daniels 2004, pp. 6, 12, 27).

Key West National Wildlife Refuge

Efforts to define the limits of the KWNWR metapopulation were
conducted from November 2006 to July 2007 (Cannon et al. 2007, pp. 10-
11; 2010, p. 849). Miami blues were found at seven sites on five
islands in the Marquesas Keys, approximately 18 to 23 mi (29 to 37 km)
west of Key West, and on Boca Grande Key, approximately 12 mi (19 km)
west of Key West (Cannon et al. 2007, pp. 1-24; 2010, pp. 847-848). The
eight sites occupied by Miami blues ranged from approximately 0.25 to
37.10 ac (0.1-15.0 ha) (Cannon et al. 2007, p. 6; 2010, p. 848). The
combined amount of upland habitat of occupied sites (within KWNWR) was
roughly 59 ac (23.8 ha) (Cannon et al. 2010, p. 848). Miami blues were
not found on Woman Key, approximately 10.1 mi (16.2 km) west of Key
West, or Man Key, approximately 6.8 mi (10.9 km) west of Key West;
these sites had abundant nectar plants, but few host plants (Cannon et
al. 2007, pp. 5, 12; 2010, pp. 848-850). In addition, the Miami blue
was not found on six islands in the Great White Heron National Wildlife
Refuge (GWHNWR); these sites contained limited amounts of, or were
lacking, either host plants or nectar plants (Cannon et al. 2007, pp.
5, 12; 2010, pp. 847, 850-851).
In a separate study, Daniels also found four of the sites
previously occupied within KWNWR to support the Miami blue variously
from 2008 to 2010 (Emmel and Daniels 2008, pp. 7-10; 2009, pp. 9-13;
Daniels 2008, pp. 1-6; Daniels 2010, pp. 3-5; J. Daniels, pers. comm.
2010a). Survey effort, however, was limited. Some previously occupied
islands were not searched, and no new occupied areas were identified.
Followup presence and absence surveys by KWNWR in 2009 showed that
the Miami blue was present on two sites in the Marquesas, but not on
Boca Grande (P. Cannon, pers. comm. 2010a). In 2010, similar surveys
indicated that the Miami blue was present on Boca Grande and one site
in the Marquesas; it was still not located on Woman Key (P. Cannon,
pers. comm. 2010b; T. Wilmers, pers. comm. 2010a). In March and April
2011, Miami blues were still present on five of seven sites where
previously found in KWNWR (T. Wilmers pers. comm. 2011a; Haddad and
Wilson 2011, p. 2).

Reintroductions

Although Miami blue butterflies were successfully reared in
captivity, reintroductions have been unsuccessful. Since 2004,
approximately 7,140 individuals have been released (J. Daniels, pers.
comm. as cited in FWC 2010, p. 8). Initially, larvae were released in
the vicinity of Flamingo at multiple locations within ENP (J. Daniels,
pers. comm. 2012). Between August 2007 and November 2008,
reintroduction events were carried out at BNP and DJSP 12 times
resulting in the release of 3,553 individuals (276 adults/3,277 larvae)
(Emmel and Daniels 2009, p. 4). Monitoring efforts have been limited;
19 days were spent monitoring reintroduction sites (Emmel and Daniels
2009, p. 4). To date, no evidence of colony establishment has been
found (Emmel and Daniels 2009, p. 4). It is not clear why
reintroductions were unsuccessful. Numerous factors may have been
involved (e.g., predation, parasitism, insufficient host plant or
larval sources). Due to limited resources and other constraints,
standard protocols were not employed to help identify factors that may
have influenced reintroduction success. Research with surrogate species
may be helpful to better establish protocols and refine techniques for
the Miami blue prior to future propagation and reintroduction efforts.

Population Estimates and Status

Bahia Honda State Park Metapopulation

Prior to its apparent extirpation, the metapopulation at BHSP was
monitored regularly from 2002 to 2009 (Emmel and Daniels 2009, p. 4).
Pollard transects (fixed-route transects walked weekly under favorable
weather conditions) at the south-end colony site (largest) yielded
annual peak counts of approximately 175, 84, 112, and 132, from 2002 to
2005 (prior to hurricanes), and 82, 81, 120, and 38, from 2006 to 2009
(Emmel and Daniels 2009, p. 4). From October 2002 to September 2003,
abundance estimates using mark-release-recapture (Schnabel method)
ranged from a low of 19.7 in February 2003 to a high of 114.5 in June
2003 (Emmel and Daniels 2004, p. 9).
Counts ranged from 6 to 100 adults during surveys by the NABA,
conducted from February 2004 to January 2005 (NABA 2005, unpub. data).
Monthly (2003 to 2006) or bimonthly (2007) monitoring by Salvato (pers.
comm. 2011c) at the south-end colony produced annual average counts of
129, 58, 46, 6, and 8, respectively, from 2003 to 2007. Salvato (pers.
comm. 2011c) observed 21, 10, and 0 Miami blues from 2008 to 2010,
respectively, based on limited surveys.
Due to the differences in methodologies and other factors, the
above estimates cannot be compared. Although abundance of select
butterflies may change frequently, their overall geographic
distribution from year-to-year is often more consistent. Given that the
Miami blue has overlapping generations and, at times, capacity for
explosive growth, it may be useful to report population status in terms
of occupied habitat, as has been done for other butterflies (Longcore
et al. 2010, pp. 335-346; T. Longcore, in litt. 2011).
In general, early (dry) season numbers were low in most years and
were attributed to a persistent south Florida drought (Emmel and
Daniels 2009, p. 4). Abundance trends indicated that there was a marked
decrease in the number of

[[Page 20955]]

individuals during the winter months (November to February) (Emmel and
Daniels 2004, p. 9; 2009, p. 4). Higher abundances during the summer
wet season may relate to production of a large quantity of new terminal
growth on the larval host plants (nickerbean) and availability of
nectar sources from spring rainfall (Emmel and Daniels 2004, pp. 9-11).
Four hurricanes affected habitat at BHSP in 2005, resulting in
reduced abundance of Miami blue following subsequent storms that
continued throughout 2006 (Salvato and Salvato 2007, p. 160). Although
no quantitative measurements were taken, a significant portion of the
nickerbean in the survey area (> 35 percent of the area of available
habitat) was damaged by the storms; roughly 60-80 percent of the
vegetation on the southern side of the island was visually estimated to
have been heavily damaged, including large stands of host and nectar
plants (Salvato and Salvato 2007, p. 156). Despite a decline in
abundance after the hurricanes, the Miami blue had appeared to rebound
toward pre-storm abundance by the summer months of 2007 (Salvato and
Salvato 2007, p. 160). However, peaks remained below those found prior
to the 2005 hurricane season (Emmel and Daniels 2009, p. 4).
Although it is unclear when iguanas became established at BHSP,
effects of herbivory on the host plant were apparent by late 2008 or
early 2009 (Emmel and Daniels 2009, p. 4; Daniels 2009, p. 5; P.
Cannon, pers. comm. 2009; A. Edwards, pers. comm. 2009; P. Hughes,
pers. comm. 2009; M. Salvato, pers. comm. 2010a). Defoliation was
mostly limited to the south-end colony site (Emmel and Daniels 2009, p.
4). Cooperative eradication efforts to address this problem began in
2009 and continue today; however, iguanas continue to impact terminal
nickerbean growth (see Summary of Factors Affecting the Species) (Emmel
and Daniels 2009, p. 4; Daniels 2009, p. 5; E. Kiefer, BHSP, pers.
comm. 2011a). From 2006 through 2009, adult or immature Miami blues
were found at several colony sites; however, one colony became
relatively unproductive in 2005 (pre-hurricane) (Emmel and Daniels
2009, p. 4). No Miami blues have been found at any roadway nickerbean
patches within BHSP since 2005, prior to the advent of profound iguana
herbivory and damages from hurricanes (Emmel and Daniels 2009, p. 4).
The metapopulation has diminished in recent years likely due to the
combined effects of small population size, drought, cold temperatures,
and iguanas (see Summary of Factors Affecting the Species). In 2010,
few Miami blues were observed at BHSP. On January 23, 2010, a
photograph was taken of a pair of Miami blues mating (Olle 2010, p. 5).
On February 12, 2010, a photograph was taken of a single adult (C.
DeWitt, pers. comm. 2011). In March 2010, Daniels found one larva, but
no adults (D. Cook, FWC, pers. comm. 2010a). In July 2010, a single
adult was observed and photographed (A. Edwards, pers. comm. 2011). No
Miami blue adults have been located during quarterly surveys conducted
in 2010 by Salvato (pers. comm. 2010b, 2011c). No Miami blue
butterflies of any life stage were subsequently seen despite frequent
searches (D. Cook, pers. comm. 2010a; P. Cannon, pers. comm. 2010c,
2010d, 2010e, 2010f; M. Salvato, pers. comm. 2011c, 2011d; Jim
Duquesnel, BHSP, pers. comm. 2011a, 2011b).

Key West National Wildlife Refuge Metapopulation(s)

The metapopulation at KWNWR yielded counts of several hundred, at
various times, in 2006-2007. Checklist counting, a method where
suitable habitat is initially screened to determine the presence of
target species, was used during surveys conducted between November 2006
and July 2007 to document the distribution and abundance of Miami blues
(Cannon et al. 2007, p. 5; 2010, p. 848). Within the seven sites
occupied in the Marquesas Keys, the highest counts ranged from 8 to
521, depending upon site and sampling date (Cannon et al. 2007, p. 7;
2010, p. 848). The highest count on Boca Grande was 441 in February
2007 (Cannon et al. 2007, p. 7; 2010, p. 848). Highest counts occurred
when blackbead flowered profusely and produced new leaves (Cannon et
al. 2010, p. 851). In March and April, blackbead was observed to yield
little new growth and no flowering, and oviposition by Miami blues was
not observed (Cannon et al. 2007, p. 8). Partial searches on two
islands in May and June revealed few Miami blues; little new leaf
growth and no flowering of blackbead was observed at these locations
after February 2007 (Cannon et al. 2010, p. 850). Seasonality observed
on KWNWR was different than that described for the BHSP metapopulation
(above). Hurricane Wilma (October 2005) heavily damaged or killed
blackbead stands at most sites, but it also likely enhanced foraging
habitat, if only temporarily, on select islands within the KWNWR
(Cannon et al. 2007, p. 10; 2010, p. 851) (see Summary of Factors
Affecting the Species).
Periodic surveys at KWNWR in 2008 and 2009 suggested relatively
lower levels of abundance, based upon limited effort (Emmel and Daniels
2008, pp. 7-10; 2009, pp. 9-13) and using different methodologies. In
February 2008, researchers recorded 3 adults on Boca Grande and a total
of 32 adults at two islands within the Marquesas; lack of rainfall
resulted in very limited adult nectar sources and limited new growth of
larval host plants (Emmel and Daniels 2008, pp. 7-8). In April 2008,
one adult was recorded on Boca Grande; one adult was also recorded at
another island (Emmel and Daniels 2008, p. 8). In June 2008, no adults
were located on Boca Grande, and a total of 27 were recorded from two
other islands (Emmel and Daniels 2008, p. 9). In August 2008, no adults
were found at Boca Grande, and five adults were recorded at another
island (Emmel and Daniels 2008, p. 10). In March 2009, no adults were
recorded on Boca Grande; habitat conditions were deemed very poor, with
limited new host growth and available nectar resources (Emmel and
Daniels 2009, p. 12). In April 2009, researchers found a total of 22
adults from 2 islands within the Marquesas (Emmel and Daniels 2009, p.
13).
Based upon limited data and observations, the Miami blue persisted
on various islands within the KWNWR in 2010. From April through July
2010, the Miami blue was observed on 5 of 10 dates at one location
within the Marquesas, although in limited numbers during brief surveys
(T. Wilmers, pers. comm. 2010b). On July 28, 2010, researchers recorded
19 adults from 3 islands within the Marquesas, in limited surveys;
another 25 adults were recorded on Boca Grande in less than 1 hour of
survey work (J. Daniels, pers. comm. 2010a). On September 30, 2010,
dozens of Miami blues were observed on Boca Grande; this may have
represented an actual population size in the hundreds (N. Haddad, North
Carolina State University [NCSU]), pers. comm. 2010). On November 24,
2010, researchers positively identified 48 Miami blue adults on Boca
Grande in less than 3 hours of surveys, noting that assessment was
difficult due to the many hundreds or possibly thousands of cassius
blues, which were also present (P. Cannon, pers. comm. 2010b; T.
Wilmers, pers. comm. 2010a). In March and April 2011, researchers
observed Miami blue adults at five sites within KWNWR in numbers
similar to those reported above (Haddad and Wilson 2011, p. 2). In July
2011, fewer adults were observed (P. Hughes, pers. comm. 2011a). In
September 2011,

[[Page 20956]]

Refuge staff observed 14 adults on Boca Grande (P. Hughes, pers. comm.
2011b). In December 2011, 88 adults were found in roughly 4 hours (P.
Cannon, pers. comm. 2012). In January 2012, Refuge staff observed 20
adults on Boca Grande and 14 adults at one site in the Marquesas during
brief surveys under windy conditions (A. Morkill, pers. comm. 2012).
At this time, both the size of the metapopulation at KWNWR and its
dynamics are unclear. However, available data (given above) suggest
wide fluctuations of adults within and between years and sites. The
frequency of dispersal between islands is also not known (Cannon et al.
2010, p. 852). Due to the distance between the Marquesas and Boca
Grande (i.e., about 7 mi [11 km]) and the species' apparent limited
dispersal capabilities, it is possible that two (or more) distinct
metapopulations exist within KWNWR (J. Daniels, pers. comm. 2010b). In
September 2010, the Service initiated a new study with researchers from
NCSU to conduct a comprehensive examination of potential habitat within
KWNWR and GWHNWR, quantify current distribution and habitat use, and
develop a monitoring protocol to estimate detectability, abundance, and
occupancy parameters.

Gene Flow and Genetic Diversity Within Contemporary Populations

Saarinen (2009, pp. 15, 29-33, 40, 44) and Saarinen et al. (2009b,
pp. 242-244) examined 12 polymorphic microsatellite loci (noncoding
regions of chromosomes) to assess molecular diversity and gene flow of
wild and captive-reared Miami blue butterflies. In addition, one of
these microsatellite loci was successfully amplified from a subset of
the museum specimens. Although results from historical specimens should
be interpreted with caution (due both to small sample size and the
single microsatellite locus), Saarinen (2009, pp. 15, 50-51) reported
some loss of diversity in the contemporary populations, though less
than had been expected. Even with small sample sizes, historical
populations were significantly more diverse (with generally higher
effective numbers of alleles and observed levels of heterozygosity)
than BHSP; KWNWR population values were between historical values and
BHSP values (Saarinen 2009, pp. 44-46).
Both historical and contemporary populations showed evidence of a
metapopulation structure with interacting subcolonies (E.V. Saarinen
and J.C. Daniels, unpub. data as cited in Saarinen 2009, p. 49).
However, the metapopulations at BHSP and KWNWR are separated by a
distance of more than 43 mi (70 km). Given the Miami blue's dispersal
capabilities (E.V. Saarinen and J.C. Daniels, unpub. data as cited in
Saarinen 2009, p. 22), it is unlikely that they interacted. Saarinen's
work showed no gene flow and a clear distinction between the BHSP and
KWNWR metapopulations (Saarinen 2009, pp. 36, 74, 89) (see Summary of
Factors Affecting the Species).
Studies addressing molecular diversity at BHSP showed the effective
number of alleles remained relatively constant over time, at both a
monthly (generational) and annual scale (Saarinen 2009, pp. 71, 84).
Allelic (gene) richness was also stable over time in BHSP, with values
ranging from 2.988 to 3.121, when averaged across the 12 microsatellite
loci from September 2005 to October 2006. These values were lower than
those in KWNWR [3.790] (Saarinen 2009, p. 71). However, data showed
that the BHSP metapopulation retained an adequate amount of genetic
diversity to maintain the population in 2005 and 2006, despite
perceived changes in overall population size (Saarinen 2009, p. 77). No
significant evidence of a recent genetic bottleneck was found in the
BHSP generations analyzed; however, there may have been a previous
bottleneck that was undetectable with the methods used (Saarinen 2009,
pp. 72, 85, 141).
To explore the level of gene flow and connectivity between discrete
habitat patches at BHSP, Saarinen (2009, pp. 64-65) conducted analyses
at several spatial scales, analyzing BHSP as a single population (with
no subdivision), as individual colonies occupying discrete habitat
patches (as several groups acting in a metapopulation structure), and
as a division of clumped colonies versus other, more spatially distant
colonies. Analyses of microsatellite frequencies were also used to
assess gene flow between habitat patches (Saarinen 2009, p. 72). While
some subpopulations were well linked, others showed more division
(Saarinen 2009, p. 73). High levels of gene flow (and relatively little
differentiation) were apparent even between distant habitat patches on
BHSP, and the smaller patches appeared to be important links in
maintaining connectivity (Saarinen 2009, pp. 78, 141). Overall, gene
flow between habitat patches on BHSP was considered crucial to
maintaining genetic diversity and imperative for the Miami blue's long-
term persistence at this location (Saarinen 2009, p. 141).
The metapopulation structure on KWNWR is more extensive than that
which occurred at BHSP (Saarinen 2009, p. 49). Due to small sample
sizes from Boca Grande, only samples from the Marquesas Keys were used
for genetic analysis of KWNWR, and results were limited (Saarinen 2009,
pp. 66, 72). Overall, this metapopulation was found to have higher
genetic diversity (mean observed heterozygosity of 51 percent versus
39.5 percent) than the BHSP population (Saarinen 2009, p. 49). Allelic
richness (3.790 in February 2008) was also higher in KWNWR (Saarinen
2009, pp. 71, 75). Accordingly, KWNWR is a particularly important
source of variation to be considered for future conservation efforts
for this taxon (Saarinen 2009, pp. 71, 75), especially now if this is
the only extant metapopulation(s) remaining. The KWNWR metapopulation
showed signs of a bottleneck and may support the hypothesis that it is
a newly founded population (Saarinen 2009, pp. 76, 141). Further work
is needed to better understand the metapopulation dynamics and genetic
implications in this population.

Summary of Comments and Recommendations

In the proposed rule published on August 10, 2011 (76 FR 49408), we
requested that all interested parties submit written comments on the
proposal by October 11, 2011. We also contacted appropriate Federal and
State agencies, scientific experts and organizations, and other
interested parties and invited them to comment on the proposal.
Newspaper notices inviting general public comment were published in The
Miami Herald, Orlando Sentinel, Tampa Tribune, The Daytona Beach News-
Journal, and the Key West Citizen on Sunday, August 21, 2011. We did
not receive any requests for a public hearing.
During the comment period for the proposed rule, we received 37
comment letters (from 35 entities) directly addressing the proposed
listing of the Miami blue butterfly with endangered status and the
proposed listing of the cassius blue, ceraunus blue, and nickerbean
blue butterflies as threatened under similarity of appearance. With
regard to listing the Miami blue butterfly as endangered, 25 comments
were in support, 2 were in opposition, and 10 were neutral. With regard
to listing the other 3 butterflies under similarity of appearance, 4
comments were in support, and 16 comments were in opposition. Of those
comments in opposition, six suggested alternatives that were more
limited in scope (e.g., applying similarity of appearance provisions to
the Miami blue's current

[[Page 20957]]

or historical range). All substantive information provided during the
comment period has either been incorporated directly into this final
determination or addressed below.

Peer Review

In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinion from 14 individuals with
specialties that include scientific expertise with butterflies,
particularly lycaenids, and general expertise with ecology and
conservation. We received independent responses from eight of the peer
reviewers. We also received two collaborative responses from State
governmental agencies, which had been solicited as part of this
process. We address these under Comments from the State.
We reviewed all comments received from peer reviewers for
substantive and new information regarding the listing of the Miami blue
butterfly as endangered and the cassius blue, ceraunus blue, and
nickerbean blue butterflies as threatened under similarity of
appearance. The peer reviewers concurred with the conclusion to list
the Miami blue butterfly as endangered and provided additional
information, clarifications, and suggestions to improve the final rule.
In general, the majority of peer reviewers opposed Federal listing of
the three other butterflies due to similarity of appearance; however,
one reviewer agreed with the original proposal, and three suggested
applying the similarity of appearance listing only to select areas
where the butterflies may co-occur with the Miami blue.

Peer Reviewer Comments

(1) Comment: One peer reviewer indicated that the Miami blue
butterfly should remain in the genus Hemiargus, as originally
described, citing Comstock and Huntington (1943), Nabokov (1945), and
Vila et al. (2011) as relevant taxonomic papers. The reviewer noted
that only limited phylogenetic analyses have been conducted to
determine if the genus Hemiargus should be split into a variety of
additional genera, such as Cyclargus. In his view, the Miami blue is
well characterized and easily recognized, but should continue to be
treated as Hemiargus thomasi bethunebakeri and listed as such, rather
than Cyclargus thomasi bethunebakeri.
Our Response: We acknowledge that some sources continue to place
the Miami blue in the genus Hemiargus. However, our basis for using
Cyclargus is founded on published and unpublished literature, separate
confirmation of specimens from independent taxonomists or reviewers,
and other accepted taxonomic sources (see Taxonomy). We note that
several Web sites (e.g., Butterflies of America, Catalog of the
Butterflies of the United States and Canada, and the Integrated
Taxonomic Information System), widely regarded as definitive sources,
also continue to place the Miami blue as Cyclargus thomasi
bethunebakeri. We determined that this is the most appropriate
nomenclature because it is more widely accepted by the scientific
community. Therefore, we have used the genus Cyclargus in this final
rule.
(2) Comment: Two peer reviewers and five commenters expressed
concern over the Service's determination that critical habitat is not
prudent, disagreed with this decision, or otherwise suggested that we
reconsider this determination. Two commenters supported our
determination. Comments in opposition to our not prudent determination
were largely based on the potential benefits of designating critical
habitat and skepticism that increased risk and harm to the Miami blue
would occur with designation, as ample detail is already available for
poachers to locate remaining populations.
Our Response: We determined that designating critical habitat for
the Miami blue is not prudent. We recognize that designation of
critical habitat can provide benefits to listed species (see Benefits
to the Subspecies From Critical Habitat Designation, below, as well as
discussion later in this response); however, for the Miami blue,
increased threats (see Increased Threat to the Subspecies by
Designating Critical Habitat, below) outweigh the benefits (see
Increased Threat to the Subspecies Outweighs the Benefits of Critical
Habitat Designation, below).
We do not dispute the arguments of the two peer reviewers and some
commenters who suggested that industrious or unethical collectors have
enough information to be able to locate the remaining populations. We
acknowledge that general location information is provided within the
rule, and more specific location information can be found through other
sources. However, we maintain that designation of critical habitat
would more widely publicize the potential locations of the butterfly
and its essential habitat to poachers, collectors, vandals, and
mischievous individuals, thereby exacerbating the already significant
threats of collection, vandalism, disturbance, fire, and other harm
from humans.
One commenter, who agreed with our decision that designating
critical habitat is not prudent, provided additional references
(Hoekwater 1997, Kleiner 1995, O'Neill 2007) showing that individuals
poach rare and imperiled taxa for profit, even to the point of driving
a species to extinction in order to increase the value of individual
specimens (Laufer 2009). We want to stress that our reasons for not
designating critical habitat go beyond the potential increased threat
of collection, but also involve potential associated increased risks to
sensitive and important habitats (see also Inadvertent and Purposeful
Impacts From Humans, below). Designation of unoccupied habitat could
also alienate any affected private landowners and stakeholders, thus
limiting reintroduction and recovery options (see also Response to
Comment 24 below).
We agree that designation of critical habitat can provide some
benefits to listed species (e.g., a tool to restore and manage habitat
on Federal lands, greater awareness and education by the public,
increased cooperation by other agencies to improve habitat). With the
Miami blue, substantial efforts at education and active conservation
efforts from Federal, State, and local agencies are already underway,
so potential added benefits from designation would likely be minimal.
(3) Comment: One peer reviewer stated that the status of the Miami
blue is grave and that extinction is a distinct possibility. Another
peer reviewer stated that the Miami blue has an extremely high
likelihood of becoming extinct unless active conservation measures are
applied immediately.
One commenter indicated that the Miami blue is one of the rarest
butterflies in the United States and in the world. The commenter
specifically stated that it may be the single rarest butterfly species,
and is rarer than at least 14 species that are listed under the Act. He
indicated that understanding spatial and population structure and
dispersal are keys to recovery, as are restoration and reintroduction.
Another commenter, certified by the International Union for the
Conservation of Nature to evaluate extinction risk, stated that the
Miami blue meets all five criteria for listing under the Act. Another
commenter urged immediate action to address threats and the development
of a ``functional'' recovery plan, with the assistance of experts.
Another commenter encouraged the Service to take all possible steps to
recover the subspecies, stressing the importance of future
reintroductions in the best possible habitats.
Our Response: We agree. The threats to the Miami blue pose a
significant risk

[[Page 20958]]

to the subspecies and were the basis of our emergency determination,
which immediately put forth conservation measures (see Available
Conservation Measures, below). We are actively working with
stakeholders and partners to implement additional conservation actions
now to prevent extinction. We fully intend to actively engage others
and implement actions that will help ensure survival and long-term
recovery. We will work closely with scientific experts, land managers,
stakeholders, and others to ensure that any future captive propagation
and reintroduction efforts do not harm the wild population, and occur
in optimal habitat to increase the likelihood of persistence.
(4) Comment: One peer reviewer stated that the largest threat to
the Miami blue is the small size of the single remaining
metapopulation. He contended that, if the subspecies is to survive, the
priority needs to be on improving the quality of existing habitats,
enlarging breeding areas, and creating new breeding habitats, if
possible. One commenter estimated numbers at the peak of the Miami
blue's flight period in the hundreds, stating that conservation
biologists agree that numbers should be many thousands to counteract
the negative effects of inbreeding, genetic drift, and environmental
catastrophes. This commenter also stated the small area currently
occupied is ``frighteningly small'' and that additional and more
widespread sites are needed to provide insurance against the extinction
of a localized population. This reviewer and other commenters believed
that reestablishment at other locations is a priority because of the
substantial risk of extinction due to stochastic events and other
threats.
Our Response: We agree that several of the most important threats
to the Miami blue are currently small population size, few populations,
and restricted range. We concur that the actions specified are needed
and acknowledge that other actions to reduce threats are also needed
for survival and recovery (see Determination of Status, below).
(5) Comment: One peer reviewer suggested that poaching is a more
accurate term than collection. This reviewer viewed poaching as a
potential threat to the Miami blue and indicated that to spend ``two
full pages discussing hypothetical threats sounds biased'' in his view.
One commenter stated that the Miami blue has no protection from
poachers and suggested that listing may invite poachers to offshore
islands. She indicated that she has been contacted by someone
interested in acquiring rare butterflies. Another commenter noted that
listing would call additional attention from commercial traders to the
Miami blue and related species.
Our Response: We provided a thorough and detailed description of
the threat posed by collection in the proposed rule. In addition, we
believe that it is necessary to fully discuss the many activities that
go beyond collection, and include other illegal and illicit activities.
Because we do not have evidence of collection of the Miami blue, we
outline illegal and illicit activities involving other listed or
imperiled butterflies on various protected lands and the established
markets for specimens. We have determined that poaching is a potential
and significant threat that could occur at any time, but poaching is
only a subset of the activities that threaten the Miami blue. The
generic term ``collection'' is more easily understood by the public and
better encompasses the breadth of activities related to this threat.
We recognize that listing may inadvertently increase the threat of
collection and trade (i.e., raise value, create demand). However, we
have determined, based upon the best available scientific information,
that the subspecies meets the criteria for Federal protection.
Accordingly, it is our obligation to take protective action through
Federal listing to help safeguard the subspecies.
(6) Comment: Two peer reviewers indicated that a better
understanding of host plants will be essential for effective Miami blue
conservation. One noted that there is considerable ambiguity as to the
breadth of host plant use and plant-herbivore interactions. Another
peer reviewer noted the general preference of the Palos Verdes blue
butterfly for fresh growth on host plants (citing Johnson et al. 2011).
This reviewer suggested that not all available host plant mass at a
given location may be appropriate for use (larval and female egg-
laying) and that the actual available suitable host plant may be far
less than the total mass at any given site. One commenter suggested
that no natural populations of the Miami blue are known to feed on
balloonvine, despite its availability. Another commenter noted that the
Miami blue was originally associated with balloonvine, but subsequently
adapted to using gray nickerbean due to efforts to control balloonvine.
Our Response: We agree that further studies into historical and
current Miami blue host plant preferences are essential to best
conserve and recover the subspecies. Available scientific literature
documents a variety of host plants for the Miami blue (see--Life
History and Habitat under Background, above). This is consistent with
recent host plant use in contemporary Miami blue populations. The last
Miami blues observed on northern Key Largo in 1996 fed on balloonvine;
those at BHSP fed on nickerbean and blackbead; and those within KWNWR
rely primarily on blackbead. We note that balloonvine was not reported
as a host plant until the 1970s, and that host plant use appears to
have changed through time depending upon availability (see Habitat for
complete discussion). Balloonvine was likely only one of several
legumes used by historical Miami blue populations.
We agree that not all available host plants at a given location may
be appropriate for larval use and that actual available suitable host
plant mass may be far less than the total present. This is consistent
with findings from available research. For example, when the Miami blue
occurred at BHSP, only a small portion of available habitat on the
island appeared occupied, and higher abundances were found when there
was a large quantity of new terminal growth of nickerbean and when more
nectar sources were available (Emmel and Daniels 2004, pp. 9-12).
(7) Comment: One peer reviewer recommended several clarifications
regarding the description of the Miami blue (wing-chord length) and
aspects of its life history (four instars, not five).
Our Response: We have replaced the term ``wing-chord length'' with
the more frequently used measure of ``forewing.'' The term fifth-instar
was a typographical error and has been corrected with fourth-instar. We
also made other suggested minor clarifications. These changes are set
forth in the Background section of this final rule.
(8) Comment: Two peer reviewers questioned the maximum adult life
span of the Miami blue and how this was determined and suggested that
adults likely live more than 9 days. These reviewers suggested that
older individuals may be more likely to disperse and that finding them
once dispersed may be difficult. One reviewer cited research showing
that older females may be prone to longer movements (Bergman and Landin
2002, p. 361).
Our Response: We agree that the maximum 9-day life span as
discussed in the emergency rule is unclear and may be an underestimate
of natural adult life span. We have clarified the text in this final
rule accordingly. Additional field studies are needed to

[[Page 20959]]

better ascertain adult Miami blue longevity in the wild and to
determine dispersal capabilities.
(9) Comment: Three peer reviewers and one commenter questioned the
degree to which the Miami blue is sedentary, suggesting that it may be
less sedentary than described. One reviewer suggested that the
subspecies may be sedentary at certain stages of its life, but that the
Miami blue's historical range (i.e., central Florida to the Keys and
Dry Tortugas) is evidence that it disperses over wide areas of water
over long periods of time. Another suggested that it only takes a
wayward gravid female to colonize a new habitat. Another suggested that
a butterfly surviving in a metapopulation due to habitat structure such
as the Miami blue must have stronger dispersal capabilities than
described in the rule, at least in a small fraction of the population.
One commenter stated that, although the butterfly appears to be
sedentary now, it once occurred widely in the Keys and coastal areas of
central and southern Florida and that it is capable of dispersing and
colonizing new areas, including islands.
Commenters suggested that keys to designing a recovery strategy
include a clear focus on basic life history, population dynamics, and
an improved understanding of dispersal. One commenter indicated that a
well-informed recovery plan would include a strategy for multiple
interconnected populations that buffer the subspecies when some
localized populations are lost and that more information is needed
about dispersal capacity.
Our Response: We agree that the Miami blue may be less sedentary
than described and have made clarifications to the text. At this time,
it is unclear how far the butterfly can disperse and the mechanisms for
dispersal (i.e., active [flight] or passive [wind-assisted]). We
acknowledge that wayward individuals and gravid females can colonize
new areas. Clearly, additional study is needed to better understand the
Miami blue's dispersal capabilities and mechanisms. We agree that
improved understanding of basic life history and population dynamics,
including dispersal, will be key components to an effective recovery
strategy. An effective recovery strategy will likely provide for
multiple, interconnected populations that enable genetic exchange and
facilitate recolonization in the event of local extirpations.
(10) Comment: One peer reviewer indicated that diapause can be
difficult to detect. He suggested that the Miami blue, like other
closely related species, could enter diapause as third instars rather
than as adults, in response to photoperiod, temperature, or changes in
host plants.
Our Response: We acknowledge that there is some uncertainty
regarding diapause (see Life History). We believe that the Miami blue's
life history requires further study in order to better determine if any
life stages undergo a dormant period.
(11) Comment: One peer reviewer expressed his opposition of mark-
recapture methods for lycaenids, particularly small blues, such as the
Miami blue butterfly.
Our Response: We acknowledge that not enough information is known
about the influence of mark-recapture on butterflies and that it can be
harmful, depending upon the species, techniques employed, skill of
handlers, and other factors. There have been several studies of various
mark-recapture techniques with conflicting results regarding the impact
on butterflies. Recently, Haddad et al. (2008, p. 938) reviewed several
types of monitoring techniques and suggested that mark-recapture is not
appropriate for small and/or imperiled butterflies. Researchers are not
employing mark-recapture techniques on the Miami blue at this time.
(12) Comment: One peer reviewer indicated that disturbance factors
may be beneficial to the host plants and that conservationists have a
tendency to remove disturbances from protected lands, which can work
against species dependent upon early successional plants (citing
Longcore and Osborne 2010 and Longcore et al. 2010). One commenter
indicated that trampling of host plants has occurred within KWNWR.
Our Response: We agree that periodic natural disturbances may
benefit the habitat, thereby increasing the vigor or distribution of
important host plants. However, human-related disturbances (e.g.,
vandalism, trampling, camping, fire pits) can present significant risk
to the Miami blue (especially larval stages) and important stands of
host plants (see Inadvertent and Purposeful Impacts from Humans). Given
the butterfly's overall vulnerability to extinction, we acknowledge
that it will be important to minimize human-related and other
controllable threats, especially in areas of known occupied habitat.
Reducing threats will help safeguard the subspecies and its habitat.
(13) Comment: One peer reviewer stressed the importance of ant
associations among lycaenids and provided various examples and
citations. This reviewer stated that he believed that carpenter ants,
Camponotus spp., may be extremely important in the reintroduction and
long-term survival of the Miami blue at specific locations and that
successful establishment may be dependent upon presence of these ants.
Another peer reviewer cited a new paper by Trager and Daniels (2011) on
mating and egg production in the Miami blue, noting that incorporating
that study into the background does not change the outcome or
conclusions of the proposed and emergency rules. Two commenters also
noted interactions (mutualistic, predatory) between the Miami blue and
ants and suggested further investigation.
Our Response: We agree that ant associations may be an important
component of the Miami blue's life history and that further studies of
ant and Miami blue larval interactions are needed. Studies focusing on
remaining populations would be useful. However, it may also be helpful
to examine ant-larval interactions using surrogate species at
historical Miami blue locations (e.g., BHSP or Key Largo) or in the
laboratory. We have included information from the Trager and Daniels
(2011) paper in the Background (see Life History, above) and agree that
this paper does not alter the conclusions of our proposed and emergency
rules. It also does not alter the conclusions of this final rule.
(14) Comment: One peer reviewer cautioned against comparisons of
Pollard transect counts with mark-recapture abundance estimates, noting
that these two different methods of estimating population size can be
compared with similar methods but not necessarily with each other. This
reviewer suggested that, because the Miami blue has overlapping
generations and presumably the capacity for explosive growth, it might
be more productive to report population status in terms of area
occupied (citing Longcore et al. 2010).
Our Response: We agree. We understand that there are a variety of
techniques to measure abundance and monitor butterfly populations and
have clarified discussion of available data (see Population Estimates
and Status, above). Researchers are currently refining methods and
techniques to most effectively gauge population size within KWNWR,
including seasonality, as part of an ongoing study the Service funded
in 2010. Gauging overall status in terms of occupied habitat, as has
been done for other butterflies, may be more meaningful (Longcore et
al. 2010, pp. 335-346; T. Longcore, in litt. 2011).
(15) Comment: One peer reviewer noted that Clench only made one
collecting trip to the West Indies (the

[[Page 20960]]

Bahamas before 1941) (see Clench 1941).
Our Response: We have clarified the text in this final rule
accordingly.
(16) Comment: One peer reviewer was concerned about a proposed
project to develop a zip-line course at Crane Point in the City of
Marathon and suggested that the Service work closely with the City to
minimize potentially adverse impacts of such a development to the
recovery of the Miami blue.
Our Response: We were not aware of this particular project, but we
are coordinating with agencies and partners regarding various
development projects within Monroe County to avoid and minimize impacts
to the Miami blue and other federally listed species. We will work
closely with the City of Marathon and others on this potential project
as well.
Comments Relating to Similarity of Appearance Butterflies
(17) Comment: Six peer reviewers and ten commenters opposed listing
the other butterflies due to similarity of appearance, as proposed, for
a variety of reasons. The proposed action was generally opposed because
it was thought to be overly restrictive or not needed because the
similar butterflies are common and can be readily differentiated from
the Miami blue based upon clear morphological differences.
Some reviewers and commenters supported the listing of the similar
butterflies as proposed. Other reviewers, commenters, and FWC suggested
alternatives for application of the similarity of appearance provision
of the Act. These alternatives consisted of limiting application to
only areas where the butterflies are sympatric with the Miami blue
(potential or occupied habitat), only within critical habitat (if
designated), only within specified counties, or only within counties
within the Miami blue's historical range.
Those in opposition generally believed that listing similar
butterflies would impede research and discourage cooperation or
scientific support for future listing actions. Several commenters
indicated that it would negatively and needlessly impact collectors,
hobbyists, and those who collect insects for educational purposes. One
commenter stated that there should not be any restrictions on the sale,
purchase, or gifts of legally obtained cassius, ceraunus, or nickerbean
blue butterflies. One commenter warned that the ``unnecessary ban on
collection and commerce'' of the three ``similar'' species could
ultimately harm the butterflies by impeding research and future
discoveries, and also harm the relationships between the Service and
hobbyist collectors, researchers, and naturalists. The same commenter
suggested that careful monitoring and patrolling of occupied and
historical suitable sites may be a more effective protective measure
than enforcing a ban on collection and commercial transactions
involving these taxa at a state or national level.
Another commenter noted that the action was not necessary because
those seeking to collect the Miami blue or similar species on protected
conservation lands would theoretically already possess the necessary
permits. Some commenters suggested that listing due to similarity of
appearance was inconsistent with other butterfly listings that have
similar species that more closely resemble each other and do not have
similarity of appearance provisions.
Our Response: We carefully considered all of the comments received
and agree that prohibiting collection, possession, and trade of these
similar butterflies throughout their national and international ranges
could result in unnecessary restrictions and regulatory burdens. After
careful review of the needs of the Miami blue and the potential impacts
of the special 4(d) rule as originally proposed, we have reconsidered
this aspect of the proposed rule and have made significant changes
regarding its application. Consequently, in this final rule, only
collection of these similar butterflies within the current and
historical range of the Miami blue butterfly will be prohibited. See
Summary of Changes from Proposed Rule, below, for more detail.
We maintain that the Miami blue, due to its small population size
and few populations, faces a significant threat from collection, and
that prohibiting collection of similar butterflies within the
historical range of the Miami blue is in the best interest of the
subspecies. We have determined that limiting application of the special
4(d) rule to only the act of collecting and only within the historical
range of the Miami blue is sufficient to protect the subspecies from
threats faced due to collection pressure on the three similar
butterflies. The proposed restrictions on trade and commerce have been
removed, thus eliminating unnecessary restrictions and reducing
regulatory burdens for most potentially affected parties (i.e.,
elsewhere in Florida, other countries). We value relationships and are
committed to working cooperatively with stakeholders to relieve
unnecessary burdens while safeguarding the subspecies.
With regard to concerns regarding research, studies can be
conducted on the similarity of appearance butterflies in the vast
majority of their ranges (i.e., outside of Florida, outside of the
affected counties in Florida). For research in south and central
Florida, many scientific activities involving the similar butterflies
will only need prior written authorization (e.g., a letter) from the
Service. See Special Rule Under Section 4(d) of the Act below for more
information.
We agree that increased patrols and monitoring may be helpful in
deterring collection of the Miami blue. However, due to limited
resources, this may not be feasible.
We disagree with views that listing the other butterflies due to
similarity of appearance is unnecessary because those seeking to
collect the Miami blue or similar species on conservation lands would
already possess the necessary permits. We are aware of cases where
federally listed species have been collected from conservation lands
illegally or without permits (see Collection, below) and acknowledge
that listing may increase demand for specimens. We have determined that
the similarity of appearance provisions will help deter potential
collection of Miami blues (purposeful or inadvertent) in all areas
within its historical range, including those areas that are not
conserved or those in private ownership.
Finally, we acknowledge that similarity of appearance has not been
previously applied to arthropods (including insects, such as
butterflies) prior to this listing, but it is a tool available to us
under the Act. Similarity of appearance protections can be effective in
situations where collection is a primary threat and population sizes
are extremely low, as in the case of the Miami blue butterfly. We have
determined that a special rule listing the additional three butterflies
is necessary in this instance to protect the subspecies from collection
throughout its current and historical range.
(18) Comment: One peer reviewer indicated that, if listing creates
demand for collectors, then listing of the other similarity of
appearance butterflies will increase the likelihood of intentional or
unintentional collection of the Miami blue. Another reviewer and a
commenter suggested that listing would increase their values to
collectors. Other reviewers and commenters believed that the issue of
illegal collection of the Miami blue is unlikely to be deterred by
listing the three additional co-occurring, common butterflies.

[[Page 20961]]

Our Response: Although we agree that listing may create demand for
some collectors, we find that prohibiting collection of the similarity
of appearance butterflies within the Miami blue's historical range will
help reduce the threat of collection for the Miami blue. Through this
action, the public and all stakeholders will be aware that the
collection of the Miami blue and other similar blue butterflies in
coastal south and central Florida is prohibited and illegal.
(19) Comment: One peer reviewer questioned if the other similarity
of appearance butterflies would remain listed should the Miami blue
butterfly become extinct.
Our Response: If the Miami blue becomes extinct, the similarity of
appearance butterflies will remain listed until the Miami blue becomes
delisted, or we deem that the similarity of appearance protections are
no longer necessary. In either of these scenarios, the Service would
need to have adequate scientific data suggesting these actions are
warranted, and then proceed with the normal rulemaking process (i.e.,
publish proposed and final rules in the Federal Register).

Comments From the State

Section 4(i) of the Act states, ``the Secretary shall submit to the
State agency a written justification for his failure to adopt
regulations consistent with the agency's comments or petition.''
Comments received from the State are addressed below.
(20) Comment: The FWC stated that it did not have any additional
data or other information that would lead to different conclusions
regarding the Miami blue's threats, life history, or other ecological
attributes. The FWC supported our decision not to designate critical
habitat. With regard to listing the other three blues as threatened due
to similarity of appearance, the FWC supported the listing of the other
blues, but suggested that it need only apply to the counties within the
Miami blue's historical range. The FWC also encouraged the use of their
management plan as a basis for the Federal recovery plan and other
management and recovery actions.
Our Response: We agree with the FWC's recommendation to apply
similarity of appearance protection only in the counties within the
Miami blue's historical range and have modified this final rule
accordingly in response to these and other comments received. See
Summary of Changes from Proposed Rule, below.
We intend to draw upon the State's management plan for the Miami
blue and all other relevant sources during recovery planning and
implementation efforts. We will be soliciting input from the State and
other stakeholders, who are integral in the conservation of the
subspecies, during recovery planning.
(21) Comment: The Florida Department of Environmental Protection
(FDEP) found the proposed rule to be comprehensive and suggested no
changes. The FDEP noted the thorough evaluation of research by Zhong et
al. (2010), which demonstrated that a single treatment within normal
mosquito control operations can kill substantial Miami blue larvae in
targeted residential areas and, to a lesser extent, in adjacent
nontarget areas. The FDEP suggested this research may indicate that
normal mosquito control operations may have played a role in the
historical decline of the Miami blue and other Keys insect fauna. The
FDEP recommended that research be continued to better understand the
impacts of mosquito control and exotic fire ants.
Our Response: We agree that additional research will be helpful in
developing a more thorough understanding of impacts from mosquito
control, fire ants, and other threats. We are interested in working
with others to better understand and address threats.

Federal Agency Comments

(22) Comment: The Naval Air Station Key West (NAS) expressed its
commitment to work proactively with the Service to address potential
issues should the Miami blue be listed as endangered. The commenter was
concerned that, if critical habitat was designated, this would have
significant impacts on the Navy's ability to conduct mission-essential
activities.
Our Response: We appreciate the Navy's assistance in the
conservation of the Miami blue and acknowledge their concerns. We have
worked cooperatively with the Navy regarding their Integrated Natural
Resource Management Plan (INRMP) for NAS and realize it affords many
provisions for successful ecosystem management and protections for
listed species. We will coordinate with NAS to incorporate conservation
actions for the Miami blue into their INRMP.

Public Comments

Comments Relating to Critical Habitat
(23) Comment: Several commenters encouraged the designation of
critical habitat, emphasizing the need and importance of such
designation, especially for reintroduction and recovery. One commenter
stated that there is unquestionably habitat on the Keys and in south
Florida that is critical to the butterfly's recovery. Another commenter
stated that critical habitat designations are required to ensure
successful reintroductions of Miami blue populations elsewhere in its
historical range. These commenters indicated that such designation is
imperative for achieving recovery goals for the Miami blue and
recommended that high-quality target areas for reintroduction be listed
as critical habitat. One commenter suggested that designating critical
habitat has the benefit of doubling the likelihood that an endangered
species will recover.
Our Response: We acknowledge that there are benefits to designating
critical habitat, as the commenters suggest (see Benefits to the
Subspecies From Critical Habitat Designation, below). For the Miami
blue, we have determined that increased harm to the subspecies and its
habitat outweighs the benefits that critical habitat may provide (see
Increased Threat to the Subspecies by Designating Critical Habitat and
Increased Threat to the Subspecies Outweighs the Benefits of Critical
Habitat Designation, below).
We disagree that designation of critical habitat is required or
needed for successful reintroductions of the Miami blue, or that it is
imperative for achieving recovery. Landowner permission is needed to
reintroduce endangered species, even if unoccupied critical habitat is
present. Some private property owners in the Keys have reportedly
threatened to clear vegetation from undeveloped parcels to avoid
restrictions regarding the butterfly (M. Minno, in litt. 2011b; N.
Pakhomoff-Spencer, consultant, pers. comm. 2011). Designation of
critical habitat would also preclude the use of nonessential
experimental populations (NEPs) under section 10(j) of the Act, a tool
that could be useful to help reintroduce the subspecies in select areas
within its historical range in the future. Section 10(j)(2) of the Act
prohibits the use of NEPs where critical habitat is designated (the two
are mutually exclusive). Overall, we believe that successful
reintroductions and recovery will be dependent upon improved captive
propagation and reintroduction techniques, removal of controllable
threats, and cooperation of landowners, stakeholders, and partners.
Finally, with regard to the recommendation to include targeted
high-quality reintroduction sites as critical habitat, there is
currently no accepted, established list of high-quality reintroduction
sites, as implied.

[[Page 20962]]

Preliminary assessments to determine the best potential reintroduction
sites are outdated. Since originally assessed, additional populations
of the Miami blue (using a different host plant) have been found, we
have a better understanding of threats, and the captive colony no
longer exists. We expect to reevaluate potential reintroduction sites
to determine those most suitable with the help of our partners and
prior to future captive propagation, reintroduction, and monitoring
efforts.
(24) Comment: Two commenters suggested that it is not feasible to
eliminate all threats throughout the Miami blue's historical range, but
that designating critical habitat will have the benefit of identifying
focused management zones for persistence. One commenter suggested that
critical habitat should provide additional benefits in that spraying
for mosquitoes would be prohibited, host plants would be completely
protected, and invasive species would be removed. He argued that
without designating critical habitat there are few regulatory
mechanisms that will mitigate illicit activities contributing to
habitat destruction at potential reintroduction sites within the
historical range.
Another commenter acknowledged the value of designating critical
habitat for conservation and management purposes and suggested that the
limited amount of remaining vital habitat be identified for the Miami
blue. He suggested that site assessments conducted during the
unsuccessful reintroduction efforts could help identify this habitat.
This commenter indicated that designating all undeveloped coastal areas
as critical habitat is too sweeping and ignores the potential for more
specific environmental requirements, which may help explain the failure
of the reintroduction efforts. Additional studies to identify habitat
requirements were recommended.
Our Response: We agree that it is not possible to eliminate all
threats throughout the Miami blue's historical range and acknowledge
that designating critical habitat could help focus management actions.
However, we determined that designation of critical habitat is not
prudent for the Miami blue for the reasons stated below (see Critical
Habitat and Prudency Determination and explanatory sections that
follow).
With regard to threats, it is not realistic to assume that critical
habitat designation would remove threats such as mosquito-control
pesticides, completely protect host plants, or guarantee that invasive
species would be removed, as one commenter purports. Critical habitat
only provides protections where there is a Federal nexus (i.e., actions
that come under the purview of section 7 of the Act) (see Benefits to
the Subspecies from Critical Habitat Designation, below). Mosquito
control activities are not normally considered Federal projects, and
would therefore not typically be subject to section 7 review.
Furthermore, a landowner is not obligated to conduct conservation
actions, such as the removal of invasive plants, when critical habitat
is designated.
We disagree with the view that there are few regulatory mechanisms
that will mitigate activities contributing to habitat destruction
within the subspecies' historical range. Sections 7, 9, and 10 of the
Act (see Available Conservation Measures, below) can provide useful
regulatory mechanisms that will help conserve the Miami blue in its
current and historical range. In addition, listing facilitates
proactive programs and partnerships that can help protect and restore
habitats and implement recovery actions (e.g., section 4 and 6 of the
Act; see Available Conservation Measures, below). In short, some
commenters may have overestimated the potential benefits of critical
habitat designation and underestimated the regulatory protections that
the Act confers simply when a species is listed as endangered.
Finally, we agree that additional studies to identify specific
habitat requirements are needed. Such studies would be helpful to both
understanding the Miami blue's specific physical and biological habitat
needs and for increasing the likelihood of successful reintroductions
in the future. These actions will likely be undertaken with researchers
and others during recovery planning and implementation.
(25) Comment: One commenter stated that the conditions given under
50 CFR 424.12(a)(1) for a not prudent determination would apply to most
endangered species, especially insects that maintain small populations.
The commenter contended that the increased threat to the Miami blue
from designating critical habitat would be minimal because most
suitable habitat exists within protected State and Federal lands.
Our Response: We disagree that a ``not prudent'' determination
would apply to most endangered species. However, we acknowledge that it
may often apply to endangered insects and plants that are highly sought
after by collectors, hobbyists, and enthusiasts (e.g., butterflies,
tiger beetles, orchids, cacti). Although we acknowledge that most
suitable habitat for the Miami blue is on State, Federal, or other
conservation land, we do not agree with the commenter's view that
increased threat to the butterfly from designation would be minimal. In
fact, we find that the increased threat may be substantial in that it
could exacerbate the already serious threats of collection, vandalism,
disturbance, fire, and other harm from humans (see Increased Threat to
the Subspecies by Designating Critical Habitat, below).
(26) Comment: Two commenters suggested that since high-quality
target areas for reintroduction are all located on Federal, State, or
conservation lands, there would not be significant economic consequence
to designating critical habitat.
Our Response: We agree that the majority of suitable and potential
habitat for the Miami blue occurs on Federal, State, or conservation
lands. Our determination is that critical habitat designation for the
Miami blue is not prudent. Therefore, an economic analysis was not
required by the Act and was not conducted.
Comments Related to Taxonomy and Current Distribution
(27) Comment: The National Environmental and Planning Agency of
Jamaica provided comments prepared by the Scientific Authority of
Jamaica regarding the relative abundance and distribution of the
cassius blue butterfly in that country. It indicated that it did not
have data to support the suspected decline in Jamaica and had
insufficient evidence to concur with the proposal. The agency suggested
a population and distribution study was needed to determine
conservation status in Jamaica.
Our Response: We appreciate the comments provided. However, the
proposed rule did not suggest listing the cassius blue butterfly on the
basis of imperilment. Rather, it proposed threatened status for the
cassius blue solely due to its similarity in appearance to the Miami
blue, and to provide greater protection for the Miami blue. In response
to comments received during the public comment period, the similarity
of appearance aspect of the final rule has been modified. The Service
no longer sees a need to list the cassius blue, ceraunus blue, or
nickerbean blue butterflies as threatened throughout their ranges.
Rather, we believe that prohibiting collection of these similar
butterflies only in the historical range of the Miami blue in Florida
is sufficient for minimizing the threat of collection of the Miami
blue.

[[Page 20963]]

Therefore, the cassius blue will not be listed under the similarity of
appearance provision of the Act in Jamaica (see Summary of Changes from
Proposed Rule, below.).
(28) Comment: Five commenters expressed concern regarding taxonomy
and current distribution. Another commenter stated that the question of
taxonomic status has been settled since multiple, independent
researchers have verified the unique standing of the Miami blue by
genitalic dissection (See also Comment 29 and Response below).
One commenter, who had previously identified captive-reared BHSP
specimens as Cyclargus thomasi bethunebakeri, noted limitations in
contemporary specimens and available literature about Cyclargus taxa.
This commenter indicated that there are morphological and genetic
differences between historical and contemporary populations of C.
thomasi in Florida [noting Saarinen (2009)] and suspected that these
disparities may indicate the presence of a Cuban entity now in the
lower Keys. However, he acknowledged that he was unaware of any
detailed morphological or genetic investigations of the Cuban entity.
Considering Florida's proximity to other West Indian populations, he
suggested that it is possible that multiple genetic entities of C.
thomasi have occurred (or do occur) in Florida, and the presence of a
more genetically diverse metapopulation within the KWNWR may be the
result of more recent immigrations from Cuba. Further, this commenter
noted an unconfirmed report that captive-bred Miami blue larvae did not
readily accept balloonvine, reinforcing his notion that historical and
contemporary populations are not the same entity.
Another commenter stated that the Service does not have the
necessary information to determine if Cyclargus thomasi bethunebakeri
is globally endangered or not since C. thomasi has recently been
reported from Cuba and appears to be secure there. He indicated that it
has not been determined if the entity in Cuba is different from the
subspecies in Florida and that it is possible that these are the same
subspecies. He also noted that C. thomasi bethunebakeri has been
reported from the Bimini Islands in the western Bahamas. In his view,
the entity in Cuba may be the same subspecies and it may be secure;
therefore, the Florida taxon is not endangered, and should not be
listed at this time.
Another commenter noted that the Cyclargus thomasi complex was not
well defined, citing Johnson and Balint (1995). This commenter
recommended that the taxonomic status be clarified.
Another commenter indicated the differences between photographs she
had taken from BHSP with those she had discovered within KWNWR. She
suggested the possibility that the KWNWR colonies may more closely
resemble those of Cuba and elsewhere, rather than those from mainland
Florida. She noted that the range of the butterfly does not seem well
documented in recent years, and that the full range outside of the
known locations should be determined.
Our Response: We understand the commenters' questions and
uncertainty regarding taxonomy and distribution. We disagree with the
comment that the subspecies is not well defined or described. The best
scientific and commercial information and evidence indicates that
Cyclargus thomasi bethunebakeri is a distinct, well-described and
examined taxon (see Taxonomy, above) and that its distribution is
limited (see Historical Distribution and Current Distribution).
Some concerns over the taxonomy and current distribution are based
on discussion of a similar looking blue butterfly recently documented
in Cuba. Historically, the nickerbean blue, Cyclargus ammon, was
reported from Cuba. However, Hernandez (2004, p. 100) indicated that an
undetermined subspecies of Cyclargus thomasi is now also known to occur
on the island. Craves (2004, p. 43) indicated that she observed C.
thomasi commonly at two locations in Cuba: Cayo Paredon and Santiago de
Cuba. Based on examination of photographs, she suggested that these
appeared to be C. t. bethunebakeri. However, no specimens were
collected and, to our knowledge, there have been no additional studies
of the Cuban C. thomasi. Craves (2004, p. 43) suggested the possibility
that C. t. bethunebakeri recolonized Florida from Cuba.
We acknowledge the concerns raised by some commenters regarding
taxonomy, but we do not have any scientific evidence to suggest that
Cyclargus thomasi bethunebakeri also now occurs in Cuba or that it
recently immigrated from Cuba to Florida. Other subspecies of C.
thomasi occur in the Caribbean (Smith et al. 1994, p. 129), and it is
possible that the unidentified C. thomasi in Cuba is one of these
subspecies, another subspecies that has not yet been described, or
possibly C. t. bethunebakeri. Additional work to better understand the
full range of the Miami blue outside of the known locations would be
helpful. Surveys of remote areas in Florida are ongoing; additional
surveys in the Bahamas (and Cuba) would be helpful. Additional research
could help determine if other Caribbean taxa are also imperiled.
It is unlikely that Cyclargus thomasi has only recently established
in the lower Keys, as one commenter suggested. There were few
historical surveys for butterflies at BHSP or KWNWR; therefore, it is
unknown how long the Miami blue occurred at these locations prior to
their discoveries. By contrast, many of the other islands in the lower
Keys have been continually monitored for butterflies for several
decades. If the Miami blue had recently colonized the lower Keys, it
seems likely that it would have attempted to establish at numerous
locations along the chain of islands, thereby being observed and
reported prior to ultimately colonizing BHSP and KWNWR.
The concern that captive Miami blue larvae may not have readily
accepted balloonvine as the basis of historical and contemporary
populations being different entities seems unfounded. Captive
individuals and artificial conditions may produce responses that are
different than those occurring in the wild. Available scientific
literature documents a variety of host plants for the Miami blue (see
Life History and Habitat under Background--and response to Comment
6, above). Balloonvine was likely only one of several legumes
used by historical Miami blue populations.
Based on the best scientific information, including recent genetic
work, we find that Cyclargus thomasi bethunebakeri is a distinct and
unique entity, that it is limited in distribution (i.e., Florida,
possibly Bahamas), that it is imperiled, and that listing is warranted.
We lack any substantial information or evidence that the Cuban entity
is the same taxon and have no information on that entity's abundance or
status.
(29) Comment: In support of our determination, one commenter, who
had conducted her dissertation on the taxon, unequivocally stated that
the Florida subspecies, Cyclargus thomasi bethunebakeri, is unique and
imperiled. In addition to the work by multiple, independent scientists
who have verified the unique standing of the Miami blue through
dissection, this commenter cited her own additional genetic analyses,
which compared genetic sequence data of a mitochondrial gene useful in
elucidating species distinctions, and her finding of sequence
differences between multiple specimens of C. thomasi from Florida,
Cuba, and the Bahamas. The sequence data and genitalic dissections

[[Page 20964]]

make it possible to separate the bethunebakeri from others in the C.
thomasi complex. This commenter definitively stated that C. thomasi
bethunebakeri is unique and imperiled. She noted that other Caribbean
taxa are also unique and recommended research to determine if these are
also imperiled. Sequencing of specimens at additional mitochondrial and
nuclear markers would be helpful in more fully understanding the
relationship between Floridian and other Caribbean taxa of Cyclargus
thomasi.
Our Response: We agree. Based on the best scientific information,
including recent genetics work, we find that Cyclargus thomasi
bethunebakeri is a distinct and unique entity, that it is limited in
distribution (i.e., Florida, possibly Bahamas), that it is imperiled,
and that listing is warranted. We agree with the commenter's suggestion
for additional research to help determine if other Caribbean taxa are
also imperiled.
Comments Related to Threats
(30) Comment: One commenter provided considerable new information
on exotic green iguanas within KWNWR, potential impacts on the Miami
blue, and prospects for eradication. This commenter identified studies
to determine if green iguanas are eating blackbead in KWNWR as an
immediate research need. He also noted that, worldwide, there are no
known cases in which an exotic reptile, once established in an area,
has been eradicated (citing G.H. Rodda, pers. comm. 2011).
Our Response: We have incorporated new information pertaining to
green iguanas within KWNWR into the text of this final rule (see
Summary of Factors Affecting the Species, Factor E). We agree that
determining iguana food sources, both at KWNWR and within habitat
formerly occupied by Miami blues, is a crucial first step in preventing
further harm to the Miami blue from this exotic species. Because Miami
blues have historically fed on a variety of legumes, studies are needed
to determine iguana seasonal dietary preferences in south Florida and
the Keys. We are working with the U.S. Geological Survey (USGS), the
State, researchers, and others to analyze gut contents of iguanas
removed from current and historical locations. Preliminary gut content
analyses conducted by FDEP and researchers have confirmed ingestion of
at least one host plant (nickerbean) in the lower Keys (Jim Duquesnel,
pers. comm. 2012).
We agree that there is an urgent need to better understand the
extent of threat to the Miami blue and its host plants posed by iguanas
at KWNWR and elsewhere. Efforts to better understand this threat and
control or contain iguanas in select areas of Miami blue habitat are
continuing. The State and other partners have been actively working to
reduce the presence and impact of iguanas at BHSP. Efforts by FWC and
the FDEP appear to have helped control impacts to host plants at BHSP.
Iguanas are well-established throughout the islands of KWNWR. While
efforts have been made to assess this potential threat at the Refuge,
we acknowledge the difficulties with controlling iguanas and likelihood
that broad eradication efforts will be unsuccessful. In the short term,
extensive iguana eradication or containment efforts may need to be
focused in select occupied areas, future reintroduction sites, or other
areas with greatest habitat potential, where damage to host plant is
evident. Given the current distribution of iguanas in the Keys, any
island has the potential to be quickly colonized or recolonized by
iguanas, despite substantial control and containment efforts.
(31) Comment: Two commenters indicated that the role of fire in
pine rockland habitats does not need to be discussed, because the Miami
blue is a coastal butterfly that does not currently occur in fire-
maintained habitats.
Our Response: Historically, the Miami blue was documented from a
variety of habitat types, including pine rocklands (Calhoun et al.
2000, pp. 17-18) (see Habitat). We believe discussion of pine rocklands
and the need to maintain this habitat with natural or prescribed fires
is applicable, and have kept it in the final rule.
(32) Comment: One commenter indicated that mismanagement has been
an ongoing problem and that the Miami blue is thriving at remote
locations because humans have not burned, sprayed, cleared, or
developed habitat. She believed that Federal listing will do nothing to
save the Miami blue.
Our Response: We acknowledge that the Miami blue faces numerous
threats (see Summary of Factors Affecting the Species) and that its
persistence on a Refuge may be, in part, due to the absence of some
threats. Protections under the Act (through sections 7, 9, and 10) and
the recognition that immediately became available to the subspecies
with Federal emergency listing (and will continue with permanent
listing) will increase the likelihood that extinction can be prevented,
and the subspecies can ultimately be recovered (see Available
Conservation Measures, below).
(33) Comment: One commenter stated that the most likely threats to
the Miami blue are exotic predatory ants and the fragmentation and loss
of critical breeding areas.
Our Response: We acknowledge that the Miami blue faces numerous
threats (see Summary of Factors Affecting the Species). Habitat loss
and fragmentation and predation are two of many threats affecting the
butterfly.
Forys et al. (2001, p. 256) found high mortality among immature
giant swallowtails (Papilio cresphontes) from red imported fire ant
(Solenopsis invicta) predation in experimental trials and suggested
other butterflies in southern Florida might also be influenced.
Similarly, Cannon (2006, p. 7) reported high mortality of giant and
Bahamian (Papilio andraemon) swallowtail eggs from an exotic species of
twig ant on Big Pine Key. Salvato and Salvato (2010, p. 95) extensively
monitored the immature stages of the Federal candidate Florida leafwing
(Anaea troglodyta floridalis) and reported mortality from a number of
exotic and native predators, including ants.
We are not aware of any studies that have been conducted to
specifically examine the role of exotic ants on the natural history of
the Miami blue. Therefore, while we agree that exotic ants, as well as
other invasive species, have likely played a role in the decline of the
Miami blue, to date, no field studies have identified exotic ants as
specific predators of this subspecies.
(34) Comment: Other commenters acknowledged that the Miami blue
requires an active plan for reintroduction and that novel
reintroduction schemes will be an important part of its recovery.
Our Response: We agree that captive propagation and reintroduction
may be important components of the subspecies' survival and recovery,
and that innovative methods may be needed. Actions need to be carefully
planned, implemented, and monitored. Any future efforts should only be
initiated after it has been determined that such actions will not harm
the wild population, rigorous standards are met, and commitments are in
place to increase the likelihood of success and maximize knowledge
gained. Research with surrogate species may be helpful to better
establish protocols and refine techniques for the Miami blue prior to
propagation and reintroduction efforts.
(35) Comment: One commenter stated that listing will hamper
conservation efforts and research because of legal

[[Page 20965]]

restrictions. He claimed that some private property owners in the Keys
have already threatened to clear vegetation from undeveloped properties
to avoid any restrictions. He cited inconsistent funding for research
and restoration, lack of cooperation between Federal and State agencies
in recent times, and hindrances from permitting requirements and
reporting efforts. This commenter suggested that the successful
reintroductions of the Atala hairstreak (Eumaeus atala) be studied as
an example of cooperative efforts, which were only possible because
that butterfly was not listed.
Our Response: We disagree with the commenter's view that listing
will impede conservation efforts and research due to legal
restrictions. Federal listing will increase the likelihood that
extinction can be prevented and that the Miami blue may ultimately be
recovered (see Available Conservation Measures, below). Funding under
section 4 and section 6 of the Act may help implement actions that may
be difficult to undertake otherwise. The need for a section 10 permit
under the Act to conduct research on a species is dependent upon the
nature of the activity and the likelihood for incidental take. Some
research activities may require a permit; others may not. However, the
reporting requirements of a section 10 permit provide additional
benefit by ensuring the Service receives the most recent and best
available scientific information. With the Miami blue population at
critically low numbers, section 10 permits also allow us to control the
amount of take allowed for research, which might otherwise threaten the
subspecies through overutilization.
We agree with the commenter's view that funding can be
inconsistent. In general, Federal funding is limited. However, Federal
listing increases potential funding opportunities and funding sources.
We disagree with the commenter's assertion that State and Federal
agencies have not worked cooperatively in recent times. Agencies
regularly coordinate on Miami blue butterfly issues, needs, and
actions. For example, State agencies have provided vessel
transportation for researchers and staff conducting federally funded
surveys in remote areas. Federal agencies have supported previous
captive propagation efforts and more recently assisted in the formation
of a State management plan.
While we agree that Atala hairstreak releases throughout Florida
demonstrate how volunteer organizations can galvanize to work locally
towards conservation, we question its applicability to the Miami blue
situation. It is our understanding that Atala hairstreaks were
reintroduced to numerous areas, including locations where they had not
historically occurred. Any reintroduction efforts for the Miami blue
would focus on the most suitable habitat within its historical range,
with the cooperation of landowners.
There have been several successful reintroductions for endangered
blue butterflies elsewhere in the United States, such as the Karner
(Plebejus samuelis) or Mission blue (Plebejus icarioides missionensis).
We are hopeful that researchers and other conservation partners will
draw on guidance from these and other successful reintroductions prior
to undertaking future captive propagation and reintroduction efforts
for the Miami blue. State and Federal funding has been provided in
support of previous captive propagation efforts for the Miami blue. Due
to the subspecies' precarious status, it is imperative to identify the
potential causes of failure from previous efforts before future efforts
are undertaken.
(36) Comment: One commenter contended that mosquito control
activities have had minimal impact on the Miami blue butterfly. A
second commenter stated that the record clearly demonstrates that
mosquito control adulticides (insecticides targeting adult mosquitos)
have not been a primary cause (or even a substantial contributory
secondary cause) to mortality in the Miami blue and ``its sibling
species.'' A third commenter stated that mosquito spraying is not an
issue because the remaining Miami blue colonies in the KWNWR are not
sprayed.
Our Response: No comprehensive studies have been completed that
examine the impact of current or historical mosquito control activities
on Miami blue butterflies in the wild. Although there is no evidence of
mosquito control impacts on wild Miami blue populations, potential
impacts over the subspecies' historical range have never been examined.
Recent research has shown that exposure to mosquito control chemicals
in sufficient quantities can impact various butterfly species,
including captive-bred Miami blue (Zhong et al. 2010 pp. 1967-1968;
Hoang et al. 2011 pp. 1000-1002). Based on these findings, the Service
determined that mosquito control pesticides can be a threat to the
Miami blue.
(37) Comment: One commenter stated that Hennessey and Habeck (1991)
found no adverse effect on insect populations due to pesticide drift. A
second commenter stated that no harm was demonstrated in Hennessey and
Habeck (1989), Hennessey and Habeck (1991), and Hennessey et al. (1992)
when mosquito control chemicals drifted 750 meters into protected no-
spray zones.
Another commenter cited two studies (Davis and Peterson 2008,
Breidenbach and Szalay 2010) that demonstrated few deleterious effects
on insect communities following mosquito control chemical application.
Our Response: With regard to the first comment relating to
pesticide drift, the results of the aforementioned field study (all
three references detail activities associated with just one field
study) did not provide conclusive findings regarding the effects of
mosquito control spraying on the two butterfly species examined
(Florida leafwing and Bartram's hairstreak [Strymon acis bartrami]). A
greater number of adult Florida leafwing butterflies was observed in
untreated areas during one year of the study, but this difference was
not observed in the second year of the study (Hennessey and Habeck
1991, p. 14). Additionally, the study revealed that one of the
reference locations received adulticide deposition through aerial
drift, thus compromising the utility of the location to be used as a
reference site and making it difficult to discern any pesticide effects
(Hennessey and Habeck 1991, pp. 29-30).
With regard to deleterious effects of pesticides, we agree with the
other commenter's assertion that the two studies cited did not show
dramatic effects on insect communities following mosquito control
activities. There were exceptions in both studies where insect numbers
declined following treatment events (Davis and Peterson 2008, pp. 274-
276; Breidenbach and Szalay 2010, pp. 594-595). It also did not appear
that any butterfly families were included in the study, thus making it
difficult to draw any conclusions about mosquito control effects on
butterflies.
(38) Comment: Two commenters stated that current mosquito control
application methods are improved when compared to methods used in the
Hennessey and Habeck (1991) study that documented drift of mosquito
control chemicals. One of the commenters specifically stated that
mosquito spray optimization utilizing smaller and more uniform
insecticide aerosol droplets has been shown to mitigate exposure to
nontarget organisms. Two studies are cited (Zhong et al. 2003, 2004) in
support of this assertion. This same commenter also stated that the
small droplets degrade rapidly and leave little or no residue at ground
level.

[[Page 20966]]

Our Response: We acknowledge that mosquito control spraying
technology has advanced in recent years. Despite these advances, recent
research (Pierce 2009, pp. 2-15; Zhong et al. 2010, pp. 1966-1967;
Pierce 2011, pp. 6-11; T. Bargar, USGS, pers. comm. 2011) has still
documented quantifiable residues of mosquito control chemicals on
filter pads and foliage in nontarget areas.
(39) Comment: Two commenters addressed the results of Zhong et al.
(2010), a paper that assessed exposure and acute toxicity of late
instar Miami blue larvae to aerially applied mosquito control
adulticides in the field. One commenter noted that he has heard and
read multiple comments regarding the mortality level of Miami blue
caterpillars within a mosquito control spray zone from the Zhong et al.
(2010) study, cited in the emergency rule. This same commenter noted
that Miami blue caterpillar mortality in the ``drift zone'' did not
differ statistically from control organisms that were 11 mi (18 km)
from mosquito control chemical application. The second commenter noted
that larval mortality was insignificant in the ``drift zone'', despite
the fact that naled (organophosphate insecticide) residues were
detected at least once in each of those locations. This commenter
stated that these results may indicate that other variables need to be
studied. Vitality of the larvae, uneven distribution of naled residue,
and the effects of distance from the spray line on butterfly mortality
under various wind conditions and spray drift offsets are all suggested
as additional studies.
Our Response: The naled residues that were observed in the drift
zone were lower in concentration than the residues in the spray zone
(Zhong et al. 2010, p. 1966); therefore, it is not surprising that
caterpillar mortality in the drift zone was significantly lower than in
the spray zone. The mortality trend observed in mosquitoes placed in
the spray, drift, and control zones also followed a clear dose-response
similar to that of the butterfly caterpillars (Zhong et al. 2010, p.
1969). The vitality of the larvae used in the study is confirmed by the
fact that no larval mortality was observed in the control zone (Zhong
et al. 2010, p. 1969). The Service agrees with the second commenter's
suggestion that naled residue distribution and the effects of distance
from the spray line on butterfly mortality under various wind
conditions and spray drift offsets should be studied further.
(40) Comment: One commenter provided quotes from a lepidopterist
with experience studying butterflies in Florida. The lepidopterist
presented a theory, based upon unpublished field observations, that
mosquito control spraying may benefit butterfly species by decreasing
parasitoids.
Our Response: The theory presented in this comment appears to be
based solely on an individual's qualitative observations. No
quantitative methods or data are given or cited. Concrete evidence in
support of such a theory would need to be provided for further
consideration.
(41) Comment: One commenter stated that risk-based assessments to
address the probability of injury, based on actual field exposure,
rather than hazard-based assessments that simply indicate the potential
to cause injury and do not take into account environmentally relevant
exposure scenarios, should be used when examining pesticide impacts to
threatened and endangered species. They maintain these assessments
should be made in terms of long-term population-level effects, rather
than localized effects upon individual organisms. This would allow for
``inadvertent take'' provisions of the Act to be used.
Our Response: The Service agrees that risk-based assessments that
take into account actual field exposure scenarios are an effective way
to evaluate risk to threatened and endangered species. For example, in
a recent study, field deposition values for naled on the National Key
Deer Refuge (NKDR), Big Pine Key, were incorporated into a
probabilistic risk assessment that predicted significant risk to common
butterflies (Bargar 2012, pp. 1-7). Such risk assessments would examine
direct effects on individual organisms, but would also be interpreted
at the population level. This could be used to estimate take and
incidental take under the Act.
(42) Comment: One commenter stated his support for recommendations
made by the Imperiled Species Subcommittee of the Florida Coordinating
Council on Mosquito Control, which include requiring buffers for known
Miami blue populations, allowing for incidental take in areas receiving
mosquito control, and supporting additional research into nontarget
impacts from mosquito control. The commenter also indicated that it is
important to definitively map populations of Miami blues to ensure that
mosquito control activities are not unnecessarily curtailed.
Our Response: The Service supports the aforementioned
recommendations of the Imperiled Species Subcommittee and was
instrumental in the development of the recommendations. It is helpful
to identify important Miami blue habitat to help reduce threats to the
subspecies and to not unnecessarily restrict mosquito control
operations. Mapping potential suitable habitat would be more inclusive
and likely provide broader conservation benefits than mapping
populations since populations can fluctuate seasonally (or even more
frequently) based upon habitat quality, availability, and other
factors.
(43) Comment: One commenter believed that the Service should not
regulate the sale, purchase, or gifts of specimens of the Miami blue
legally obtained before the rule was enacted. With regard to the
exception for properly documented antique specimens, he noted that the
butterfly was not even described until 1941 and that there are not
likely to be many specimens at least 100 years old; if such specimens
exist, these are probably the property of major museums, not private
collectors.
Our Response: We disagree. We have determined that prohibiting the
sale and purchase of Miami blue specimens obtained before this rule is
enacted (but not specimens documented to be over 100 years old) will
help deter collection and help safeguard the subspecies. This
prohibition of sale or offering for sale automatically applies to all
pre-Act specimens of species listed as endangered under the Act. Some
authorized activities, with proper permits and documentation, would
still be allowed (e.g., exchange of museum specimens among permitted
institutions). We agree that it is not likely that many exempted
specimens of at least 100 years are in existence.

Summary of Changes From Proposed Rule

After consideration of the comments received during the public
comment period (see above), we made changes to the final listing rule.
Many small, nonsubstantive changes and corrections, not affecting the
determination (e.g., updating the Background section in response to
comments, minor clarifications) were made throughout the document. All
substantial changes relate to similarity of appearance under section
4(e) of the Act and applicable prohibitions and exceptions under
section 4(d) of the Act.
These include the following:
(1) We reduced prohibitions for the similarity of appearance
butterflies to include collection only. We have removed prohibitions
regarding possession and trade for the similarity of appearance
butterflies.
(2) We limited the collection prohibition for the similarity of
appearance butterflies to only portions

[[Page 20967]]

of their ranges. Collection of the similarity of appearance butterflies
is prohibited only within the historical range of the Miami blue.
(3) We modified the special rule under section 4(d) for the
similarity of appearance butterflies to specify that prohibitions apply
only to the act of collecting them in coastal south and central Florida
within the historical range of the Miami blue butterfly.
(4) We modified our similarity of appearance determination to
reflect the changes outlined above (see Determination of Status).
(5) We modified our discussion regarding the effects of the rule to
reflect the changes outlined above (see Effects of the Rule).
See Similarity of Appearance, Special Rule Under Section 4(d) of
the Act, Determination of Status, and Effects of the Rule below.

Summary of Factors Affecting the Species

Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may determine a species to
be endangered or threatened due to one or more of the following five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination. Each of these
factors is discussed below.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
The Miami blue has experienced substantial destruction,
modification, and curtailment of its habitat and range (see Background,
above), with an estimated >99 percent decline in area occupied (FWC
2010, p. 11). Although many factors likely contributed to its decline,
some of which may have operated synergistically, habitat loss,
degradation, and fragmentation are undoubtedly major forces that
contribute to its imperilment (Calhoun et al. 2002, pp. 13-19; Saarinen
2009, p. 36).

Human Population Growth and Development

The geographic range of this butterfly once extended from the Dry
Tortugas north along the Florida coasts to about St. Petersburg and
Daytona. It was most common on the southern mainland and the Keys, and
more localized on the Gulf coast. Examination of museum collections
indicated that specimens were common from the early 1900s to the 1980s;
the butterfly was widely distributed, existing in a variety of
locations in southern Florida for decades (Saarinen 2009, p. 46).
However, through time, much of this subspecies' native habitat has been
lost, degraded, or fragmented, especially on the mainland, largely from
development and urban growth (Lenczewski 1980, p. 47; Minno and Emmel
1994, pp. 647-648; Calhoun et al. 2002, p. 18; Carroll and Loye 2006,
p. 25).
On the east coast of Florida, the entire coastline in Palm Beach,
Broward, and Miami-Dade Counties (as far south as Miami Beach) is
densely urban, with only small remnants of native coastal vegetation
conserved in fragmented natural areas. Most of the Gulf Coast barrier
islands that previously supported the Miami blue, including Marco and
Chokoloskee Islands, have experienced intense development pressure and
undergone subsequent habitat loss (Calhoun et al. 2002, p. 18). In an
independent survey of historical sites where the Miami blue had
previously been observed or collected, half were found to be developed
or no longer supporting host plants in 2002 (D. Fine, unpub. data,
pers. comm. 2002).
Significant land use changes have occurred through time in south
Florida. Considering political and economic structure and changes,
Solecki (2001, pp. 339-356) divided Florida's land-use history into
three broad eras: frontier era (1870-1930), development era (1931-
1970), and globalization era (1971-present). Within the development
era, Solecki (2001, p. 350) noted that: ``Tremendous change took place
from the early 1950s to the early and mid-1970s. Between 1953 and 1973,
nearly 5,800 km\2\ (2,300 mi\2\) (28,997 ha/year or 11,735 ac/year) of
natural areas were lost to agricultural and urban land uses (Solecki
and Walker, 2001).'' During this time, ``an almost continuous strip of
urban development became present along the Atlantic coast'' and ``urban
land uses became well established in the extreme southeastern part of
the region, particularly around the cities of Miami and Fort
Lauderdale, and along the entire coastline heading northward to West
Palm Beach.''
Saarinen (2009, pp. 42, 46) examined museum collections in the
context of Solecki's development eras and found that Miami blue records
for Miami-Dade County were highest in the 1930s and 1940s, prior to
massive land use changes and urbanization. Records from Monroe County
(including the Keys) were most numerous in the 1970s (Saarinen 2009, p.
46). Calhoun (pers. comm. 2003b) suggested the butterfly reached peak
abundance when balloonvine invaded clearings associated with the
construction boom of the 1970s and 1980s in the northern Keys and
southern mainland and became available as a suitable host plant. If so,
this may have represented a change in primary host plant at a time when
the subspecies was beginning to decline due to continued development
and destruction of coastal habitat. Saarinen (2009, p. 46) could not
correlate decreases in natural land areas with changes in the numbers
collected (or abundance), due to several confounding factors (e.g.,
increased pesticide use, exotic species). Calhoun et al. (2002, p. 13)
also attributed the butterfly's decline to loss of habitat due to
coastal development, but acknowledged that other factors such as
succession, tropical storms, and mosquito control also likely
exacerbated the decline (see Factor E).
Habitat loss and human population growth in coastal areas on the
mainland and the Keys is continuing. The human population in south
Florida has increased from less than 20,000 people in 1920 to more than
4.6 million by 1990 (Solecki 2001, p. 345). Monroe County and Miami-
Dade County, two areas where the Miami blue was historically abundant,
increased from less than 30,000 and 500,000 people in 1950,
respectively, to more than 73,000 and 2.5 million in 2009 (http://quickfacts.census.gov). All available vacant land in the Keys is
projected to be consumed by human population increases (i.e.,
developed) by 2060, including lands not accessible by automobile (Zwick
and Carr 2006, p. 14). Scenarios developed by Massachusetts Institute
of Technology (MIT) urban studies and planning department staff
(Vargas-Moreno and Flaxman 2010, pp. 1-8) included both trend and
doubling population estimates combined with climate change factors (see
below) and show significant impacts on remaining conservation lands,
including the refuges, within the Keys. While the rate of development
in portions of south Florida has slowed in recent years, habitat loss
and

[[Page 20968]]

degradation, especially in desirable coastal areas, continues and is
expected to increase.
Although extensive loss and fragmentation of habitat has occurred,
significant areas of suitable larval host plants still remain on
private and public lands. Results from surveys (2002-2003) within south
Florida and the Keys showed that numerous areas still contained host
plants (Emmel and Daniels 2004, pp. 3-6). Results from similar surveys
in 2007-2009 suggested that 14 of 16 sites on the mainland and 20 of 22
in the Keys contained suitable habitat (Emmel and Daniels 2009, pp. 6-
8). Other researchers noted that larval host plants are common in the
Keys (Carroll and Loye 2006, p. 24; Minno and Minno 2009, p. 9). A
search of IRC's database suggests that 79 conservation areas in south
Florida contain Caesalpinia spp., 39 areas contain Cardiospermum spp.,
and 77 contain Pithecellobium spp. (www.regionalconservation.org/ircs/database/search). With significant areas of host plants still remaining
in portions of the butterfly's range, there is potential for additional
populations of the Miami blue to exist.
Acute habitat fragmentation appears to have severely diminished the
Miami blue's ability to repopulate formerly inhabited sites or to
successfully locate host plants in new areas (Calhoun et al. 2002, p.
18). Although larval host plants remain locally common, the
disappearance of core populations and extent of habitat fragmentation
may now prevent the subspecies from colonizing new areas (J. Calhoun,
pers. comm. 2003b). The Miami blue appears sedentary and is not known
to travel far from pockets of larval host plants and adult nectar
sources (J. Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, pp. 6,
13). The presence of adult nectar sources proximal to larval host
plants is critical to the Miami blue and may help explain its absence
from areas that contain high larval host plant abundance but few nectar
sources (J. Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, p. 13).

Land Management Practices

Land management practices that remove larval host plants and nectar
sources can be a threat to the Miami blue. Some actions on public
conservation lands may have negatively affected occupied habitat, but
the extent of this impact is not known. For example, the Miami blue had
been sighted in DJSP in 1996, but following removal of balloonvine as
part of routine land management, no adults were observed (L. Cooper,
pers. comm. 2002; J. Calhoun, pers. comm. 2003b; M. Salvato, pers.
comm. 2003). In 2001, following the return of balloonvine, a single
adult was observed (J. Calhoun, pers. comm. 2003b). Calhoun noted that
the silver-banded hairstreak (Chlorostrymon simaethis), which also
feeds on balloonvine, had also returned to the site. The silver-banded
hairstreak has rebounded substantially on northern Key Largo within
disturbed areas of DJSP; if any extant Miami blues remain on the
island, reestablishment in this area is possible.
Removal of nickerbean as part of trail maintenance and impacts to a
tree resulting from placement of a facility may have impacted the south
colony at BHSP in 2002 (J. Daniels, pers. comm. 2002; P. Halupa, pers.
obs. 2002). The tree was an apparent assembly area for display by
butterflies during courtship (J. Daniels, pers. comm. 2002). Damage to
host plant and nectar sources from trimming and mowing during the dry
season and herbivory by iguanas (see Factor E) impacted habitat
conditions at BHSP in 2010 (D. Olle, NABA, pers. comm. 2010). More
recently, the FDEP has worked to improve habitat conditions at BHSP
through plantings, modification of its mowing practices, removal of
iguanas, protection of sensitive areas, and other actions (R. Zambrano,
FWC, pers. comm. 2010; D. Cook, pers. comm. 2010a, 2010b; Janice
Duquesnel, Florida Park Service [FPS], pers. comm. 2010a, 2010b; Jim
Duquesnel, pers. comm. 2010, 2011b; E. Kiefer, pers. comm. 2011a).
Maintenance, including pruning of host vegetation along trails and
roadsides, use of herbicides, and impacts from other projects could
lead to direct mortality in occupied habitats (Emmel and Daniels 2004,
p. 14). Habitat previously supporting immature stages of the butterfly
on West Summerland Key is subject to periodic mowing for road
maintenance by the Florida Department of Transportation (J. Daniels,
pers. comm. 2003c); the butterfly no longer occurs at this location
(Emmel and Daniels 2004, p. 3; 2009, p. 8). Since Miami blues appear
sedentary with limited dispersal capabilities, alteration of even small
habitat patches may be deleterious.
Removal of host plants from conservation lands does not appear to
be occurring on any large scale at this time. IRC has conducted
extensive plant inventories on conservation lands within south Florida
and is not aware of any attempts to eradicate balloonvine and noted
that gray nickerbean has only rarely been controlled (i.e.,
purposefully removed or pruned, followed with herbicide treatment) (K.
Bradley, pers. comm. 2002). Nickerbean is reported to occur in all of
the State parks in the Keys. It is not removed, but where it is a
safety hazard for visitors, such as when overgrowing into trails, it is
trimmed (Janice Duquesnel, pers. comm. 2003). Removal of host plants in
or near occupied habitat remains a concern, given the subspecies' small
population size, isolated occurrences, and limited dispersal
capabilities (see Factor E).
Lack of prescribed fire on public lands may have adversely affected
the Miami blue through time, but impacts are unclear. In addition to
being found within coastal areas and hardwood hammocks, the Miami blue
was also reported within tropical pinelands, a fire-dependent habitat
(Minno and Emmel 1993, p. 134; Calhoun et al. 2002, p. 18). Calhoun et
al. (2002, p. 18) reported that, until the early 1990s, the Miami blue
most commonly occurred within pine rocklands on Big Pine Key. In the
absence of fire, pine rockland often progresses to hardwood hammock.
Lack of fire may have resulted in habitat loss; however, the extent to
which this condition occurred is unclear and difficult to assess. Since
the Miami blue is presumably sedentary, changes in vegetation due to
this and other land management practices may have exacerbated the
effects of fragmentation.
As part of its listing process, the FWC has completed a biological
status review and management plan for the subspecies (FWC 2003, pp. 1-
26). This management plan was recently revised (FWC 2010, pp. ii-39).
Although the management plan is a fundamental step in outlining
conservation needs, it may be insufficient for achieving conservation
goals and long-term persistence. Recommended conservation strategies
and actions within the plan are voluntary and dependent upon adequate
funding, staffing, and the cooperation and participation of multiple
agencies and private entities, which may or may not be available or
able to assist. Conservation strategies include suggested actions to
maintain, protect, and monitor known metapopulations; establish new
metapopulations; and conduct additional research to support
conservation (FWC 2010, pp. 17-26).
In summary, a variety of land management practices on public lands
(e.g., removal of host plants, mowing of nectar sources, and lack of
prescribed fires) may have adversely affected the Miami blue and its
habitat historically and continues to do so currently.

Climate Change and Sea Level Rise

Our analyses under the Act include consideration of ongoing and
projected

[[Page 20969]]

changes in climate. The terms ``climate'' and ``climate change'' are
defined by the Intergovernmental Panel on Climate Change (IPCC).
``Climate'' refers to the mean (average) and variability of different
types of weather conditions over time, with 30 years being a typical
period for such measurements, although shorter or longer periods also
may be used (IPCC 2007, p. 78). The term ``climate change'' thus refers
to a change in the mean or variability of one or more measures of
climate (e.g., temperature or precipitation) that persists for an
extended period, typically decades or longer, whether the change is due
to natural variability, human activity, or both (IPCC 2007, p. 78).
Various types of changes in climate can have direct or indirect effects
on species. These effects may be positive, neutral, or negative and
they may change over time, depending on the species and other relevant
considerations, such as the effects of interactions of climate with
other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-
19). In our analyses, we use our expert judgment to weigh relevant
information, including uncertainty, in our consideration of various
aspects of climate change.
Climatic changes, including sea level rise, are major threats to
south Florida, including the Miami blue and its habitat. In general,
the IPCC reported that the warming of the world's climate system is
unequivocal based on documented increases in global average air and
ocean temperatures, unprecedented melting of snow and ice, and rising
average sea level (IPCC 2007, p. 2; 2008, p. 15). On a global scale,
sea level rise results from the thermal expansion of warming ocean
water, water input to oceans from the melting of ice sheets, glaciers,
and ice caps, and the addition of water from terrestrial systems
(United Nations (UN) 2009, p. 26). Sea level rise is the largest
climate-driven challenge to low-lying coastal areas and refuges in the
subtropical ecoregion of southern Florida (U.S. Climate Change Science
Program [CCSP] 2008, pp. 5-31, 5-32). The long-term record at Key West
shows that sea level rose on average 0.088 inches (0.224 cm) annually
between 1913 and 2006 (National Oceanographic and Atmospheric
Administration [NOAA] 2008, p. 1). This equates to approximately 8.76
inches (22.3 cm) in 100 years (NOAA 2008, p. 1).
In a technical paper following its 2007 report, the IPCC (2008, p.
28) emphasized it is very likely that the average rate of sea level
rise during the 21st century will exceed that from 1961 to 2003,
although it was projected to have substantial geographical variability.
Partial loss of the Greenland and Antarctic ice sheets could result in
many feet (several meters) of sea level rise, major changes in
coastlines, and inundation of low-lying areas (IPCC 2008, pp. 28-29).
Low-lying islands and river deltas will incur the largest impacts (IPCC
2008, pp. 28-29). According to CCSP (2008, p. 5-31), much of low-lying,
coastal south Florida ``will be underwater or inundated with salt water
in the coming century.'' This means that most occupied, suitable, and
potential habitat for Miami blue will likely be either submerged or
affected by increased flooding.
The 2007 IPCC report found a 90 percent probability of an
additional 7 to 23 inches (18-58 cm) and possibly as high as many feet
(several meters) of sea level rise by 2100 in the Keys. This would
cause major changes to coastlines and inundation of low-lying areas
like the Keys (IPCC 2008, pp. 28-29). The IPCC (2008, pp. 3, 103)
concluded that climate change is likely to increase the occurrence of
saltwater intrusion as sea level rises. Since the 1930s, increased
salinity of coastal waters contributed to the decline of cabbage palm
forests in southwest Florida (Williams et al. 1999, pp. 2056-2059),
expansion of mangroves into adjacent marshes in the Everglades (Ross et
al. 2000, pp. 9, 12-13), and loss of pine rockland in the Keys (Ross et
al. 1994, pp. 144, 151-155).
Hydrology has a strong influence on plant distribution in these and
other coastal areas (IPCC 2008, p. 57). Such communities typically
grade from salt to brackish to freshwater species. In the Keys,
elevational differences between such communities are very slight (Ross
et al. 1994, p. 146), and horizontal distances are also small. Human
developments will also likely be significant factors influencing
whether natural communities can move and persist (IPCC 2008, p. 57;
CCSP 2008, p. 7-6). For the Miami blue, this means that much of the
butterfly's habitat in the Keys, as well as habitat in other parts of
its historical range, will likely change as vegetation changes. Any
deleterious changes to important host plants and nectar sources could
further diminish the likelihood of the subspecies' survival and
recovery.
The Nature Conservancy (TNC) (2010, pp. 1-4) used Light Detection
and Ranging (LIDAR) remote sensing technology to derive digital
elevation models and project future shorelines and distribution of
habitat types for Big Pine Key based on sea level rise projections by
2100, ranging from the best case to worst case scenarios described by
current scientific literature. In the Keys, models projected that sea
level rise will first result in the conversion of habitat and
eventually the complete inundation of habitat. In the best case
scenario, a rise of 7 inches (18 cm) would result in the inundation of
1,840 ac (745 ha) (34 percent) of Big Pine Key and the loss of 11
percent of the island's upland habitat (TNC 2010, p. 1). In the worst
case scenario, a rise of 4.6 feet (140 cm) would result in the
inundation of about 5,950 ac (2,409 ha) (96 percent) and the loss of
all upland habitat (TNC 2010, p. 1). If modeling is accurate, under the
worst case scenario, even upland habitat on Big Pine Key will become
submerged, thereby making the butterfly's potential recolonization or
survival at this and other low-lying locations in the Keys very
unlikely.
Similarly, using a spatially explicit model for the Keys, Ross et
al. (2009, p. 473) found that mangrove habitats will expand steadily at
the expense of upland and traditional habitats as sea level rises. Most
of the upland and transitional habitat in the central portion of
Sugarloaf Key is projected to be lost with a 0.2-meter rise (0.7-foot
rise) in sea level; a 0.5-meter rise (1.6-foot rise) in sea level can
result in a 95 percent loss of upland habitat by 2100 (Ross et al.
2009, p. 473). Furthermore, Ross et al. (2009, pp. 471-478) suggested
that interactions between sea level rise and pulse disturbances (e.g.,
storm surges or fire [see Factor E]) can cause vegetation to change
sooner than projected based on sea level alone.
Scientific evidence that has emerged since the publication of the
IPCC Report (2007) indicates an acceleration in global climate change.
Important aspects of climate change seem to have been underestimated
previously, and the resulting impacts are being felt sooner. For
example, early signs of change suggest that the 1 [deg]C of global
warming the world has experienced to date may have already triggered
the first tipping point of the Earth's climate system--the
disappearance of summer Arctic sea ice. This process could lead to
rapid and abrupt climate change, rather than the gradual changes that
were forecasted. Other processes to be affected by projected warming
include temperatures, rainfall (amount, seasonal timing, and
distribution), and storms (frequency and intensity) (see Factor E). The
MIT scenarios combine various levels of sea level rise, temperature
change, and precipitation differences with population, policy
assumptions, and conservation funding changes. All of the scenarios,
from small climate change shifts to major changes, will have
significant effects on the Keys.

[[Page 20970]]

Several recent scientific publications have also addressed problems
that the IPCC's approach had in accounting for the observed level of
sea level rise in the late 20th and early 21st centuries, and yielded
new projections which reflect the possibility of rapid contributions
from ice sheet dynamics beyond surface melting (see summaries by Church
et al. 2010, Rahmstorf 2010, and Nicholls et al. 2011). The ranges of
recent projections of global sea level rise (Pfeffer et al., 2008, p.
1340, Vermeer & Rahmstorf 2009, p. 21530, Grinsted et al., 2010, pp.
469-470, Jevrejeva et al., 2010, L07703, p. 4, (GCCUS) 2009, p. 25) all
indicate substantially higher levels than the projection by the IPCC in
2007, suggesting that the impact of sea level rise on south Florida
could be even greater than indicated above. These recent studies also
show a much larger difference (approximately 3 to 4 ft (0.9 to 1.2 m))
from the low to the high ends of the ranges, which indicates the
magnitude of global mean sea level rise at the end of this century is
still quite uncertain.
Rising sea level is an acute threat to all sites known to currently
support the Miami blue (Cannon et al. 2010, p. 852), and it appears
that habitat is now being lost (T. Wilmers, pers. comm. 2012a). Most
occupied sites are <1 meter (1.09 yd) above sea level, and none are >2
meter (2.18 yd) above sea level (Cannon et al. 2010, p. 852). Prominent
beach erosion and narrowing of dunes and coastal strands have been
documented within Boca Grande and at least one island within the
Marquesas (Cannon et al. 2010, p. 852). Considerable blackbead on one
island has eroded into the sea (T. Wilmers, pers. comm. 2012a).

Summary of Factor A

We have identified a number of threats to the habitat of the Miami
blue which have operated in the past, are impacting the subspecies now,
and will continue to impact the subspecies in the future. The decline
of butterflies in south Florida is primarily the result of the long-
lasting effects of habitat loss, degradation, and modification from
human population growth and associated development and agriculture.
Environmental effects resulting from climatic change, including sea
level rise, are expected to become severe in the future and result in
additional habitat losses. Although efforts have been made to restore
habitat in some areas, the long-term effects of large-scale and wide-
ranging habitat modification, destruction, and curtailment will last
into the future. Therefore, based on our analysis of the best available
information, present and future loss and modification of the
subspecies' habitat is a significant threat to the subspecies
throughout all of its range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Collection
Rare butterflies and moths are highly prized by collectors, and an
international trade exists in specimens for both live and decorative
markets, as well as the specialist trade that supplies hobbyists,
collectors, and researchers (Collins and Morris 1985, pp. 155-179;
Morris et al. 1991, pp. 332-334; Williams 1996, pp. 30-37). The
specialist trade differs from both the live and decorative market in
that it concentrates on rare and threatened species (U.S. Department of
Justice [USDJ] 1993, pp. 1-3; United States v. Skalski et al., Case No.
CR9320137, U.S. District Court for the Northern District of California
[USDC] 1993, pp. 1-86). In general, the rarer the species, the more
valuable it is; prices can exceed $25,000 for exceedingly rare
specimens. For example, during a 4-year investigation, special agents
of the Service's Office of Law Enforcement executed warrants and seized
more than 30,000 endangered and protected butterflies and beetles, with
a total wholesale commercial market value of about $90,000 in the
United States (USDJ 1995, pp. 1-4). In another case, special agents
found at least 13 species protected under the Act, and another 130
species illegally taken from lands administered by the Department of
the Interior and other State lands (USDC 1993, pp. 1-86; Service 1995,
pp. 1-2). Law enforcement agents routinely see butterfly species
protected under the Convention on International Trade in Endangered
Species of Wild Fauna and Flora (CITES) during port inspections in
Florida, often without import declarations or the required CITES
permits (E. McKissick, Service Law Enforcement, pers. comm. 2011).
Several listings of butterflies as endangered or threatened species
under the Act have been based, at least partially, on intense
collection pressure. Notably, the Saint Francis' satyr (Neonympha
mitchellii francisci) was emergency-listed as endangered on April 18,
1994 (59 FR 18324). The Saint Francis' satyr was demonstrated to have
been significantly impacted by collectors in just a 3-year period (59
FR 18324). The Callippe and Behren's silverspot butterflies (Speyeria
callippe callippe and Speyeria zerene behrensii) were listed as
endangered on December 5, 1997 (62 FR 64306), partially due to
overcollection. The Blackburn's sphinx moth (Manduca blackburni) was
listed as endangered on February 1, 2000 (65 FR 4770), partially due to
overcollection by private and commercial collectors. The Schaus
swallowtail (Heraclides [Papilio] aristodemus ponceanus), the only
other federally listed butterfly in Florida, was reclassified from
threatened to endangered in 1984 due to its continued decline (49 FR
34501). At the time of its original listing, some believed that
collection represented a threat. As the Schaus decreased in
distribution and abundance, collection was estimated to be a greater
threat than at the time of listing (49 FR 34501).
Collection was cited as a threat to the Miami blue in both the
original and subsequent petitions for emergency listing. The State's
management plan for the Miami blue acknowledges that butterfly
collecting may stress small, localized populations and lead to the loss
of individuals and genetic variability, but also indicates that there
is no evidence or information on current or past collection pressure on
the Miami blue (FWC 2010, p. 13). Butterflies in small populations are
vulnerable to harm from collection (Gall 1984, p. 133). A population
may be reduced to below sustainable numbers (Allee effect) by removal
of females, reducing the probability that new colonies will be founded.
Collectors can pose threats to butterflies because they may be unable
to recognize when they are depleting colonies below the thresholds of
survival or recovery (Collins and Morris 1985, pp. 162-165). There is
ample evidence of collectors impacting other imperiled and endangered
butterflies (Gochfeld and Burger 1997, pp. 208-209), host plants (Cech
and Tudor 2005, p. 55), and even contributing to extirpations (Duffey
1968, p. 94). For example, the federally endangered Mitchell's satyr
(Neonympha mitchellii mitchellii) is believed to have been extirpated
from New Jersey due to overcollecting (57 FR 21567; Gochfeld and Burger
1997, p. 209).
Although we do not have evidence of collection of the Miami blue,
we do have evidence of illegal collection of other butterflies from
Federal lands in south Florida, including the endangered Schaus
swallowtail. In 1993, three defendants were indicted for conspiracy to
violate the wildlife laws of the United States, including the Act, the
Lacey Act, and 18 U.S.C. 371 (USDC 1993, p. 1). Violations involved
numerous listed, imperiled, and common species from many locales;
defendants later pled guilty to the felonies (Service 1995, p. 1). As
part of the evidence cited in the case, defendants exchanged
butterflies

[[Page 20971]]

taken from County and Federal lands in Florida and acknowledged that it
was best to trade ``under the table'' to avoid permits and ``extra red
tape'' because some were on the endangered species list (USDC 1993, p.
9). Acknowledging the difficulties in obtaining Schaus swallowtail,
defendants indicated that they would traffic amongst each other to
exchange a Schaus for other extremely rare butterflies (USDC 1993, p.
10). These defendants engaged in interstate commerce, exchanging a male
Schaus in 1984 in the course of a commercial activity (USDC 1993, p.
11). One defendant also trafficked with a collector in Florida, dealing
the federally listed San Bruno elfin butterfly (Callophrys mossii
bayensis) (USDC 1993, p. 67).
Illegal collection of butterflies on State, Federal, and other
lands in Florida appears ongoing, prevalent, and damaging. As part of
the aforementioned case, one defendant, who admitted getting caught
collecting within ENP and Loxahatchee National Wildlife Refuge, stated
that he ``got away with it each time, simply claiming ignorance of the
laws * * *.'' (USDC 1993, p. 13). Another defendant detailed his
poaching in Florida and acquisition of federally endangered
butterflies, acknowledging that he had ``fared very well, going
specifically after rare stuff'' (USDC 1993, pp. 28-29). The same
defendant offered to traffic atala hairstreaks (Eumaeus atala), noting
that he did not do very well and had only taken about ``600 bugs in 9
days'' and that this number seemed poor for Florida (USDC 1993, p. 46).
He further stated that collecting had become difficult in Florida due
to restrictions and extreme loss of habitat, admitting that he needed
to poach rare butterflies from protected parks (USDC 1993, p. 45).
Methods to poach wildlife and means to evade wildlife regulations,
laws, and law enforcement were given as part of the evidence (USDC
1993, pp. 32-33). In a separate incident in 2008, an individual was
observed attempting to take butterflies from Service lands in the Keys
(D. Pharo, pers. comm. 2008). When confronted by a FWC officer, he lied
about his activities; a live swallowtail butterfly (unidentified) was
found in an envelope on his person, a collapsible butterfly net was
found in a nearby area, and a cooler containing other live butterfly
species was in his car (D. Pharo, pers. comm. 2008).
Additionally, we are aware of and have documented evidence of
interest in the collection of other imperiled butterflies in south
Florida. In the aforementioned indictment, one defendant noted that
there was a ``huge demand for Florida stuff,'' that he knew ``exactly
where all the rare stuff is found,'' that he ``can readily get
material,'' and that in most cases he would ``have to poach the
material from protected parks'' (USDC 1993, p. 44). More recently, one
commenter stated that she has been contacted by someone interested in
acquiring rare butterflies (see Comment 5 and Response above).
In addition, Salvato (pers. comm. 2011e) has also been contacted by
several individuals requesting specimens of two Federal candidates, the
Florida leafwing and Bartram's hairstreak, or seeking information
regarding locations where they may be collected in the field. In
addition, interest in the collection of the Florida leafwing was posted
by two parties on at least one Web site in 2010 along with advice on
where and how to bait trap, despite the fact that this butterfly mainly
occurs on Federal lands within ENP. Thus, there is established and
ongoing collection pressure for rare butterflies, including two other
highly imperiled candidate species in south Florida.
We are also aware of multiple Web sites that offer or had offered
specimens of south Florida butterflies for sale that are candidates for
listing under the Act (M. Minno, pers. comm. 2009; C. Nagano, pers.
comm. 2011; D. Olle, pers. comm. 2011). Until recently, one Web site
offered male and female Florida leafwing specimens for [euro]110.00 and
[euro]60.00 (euros), respectively (approximately $144 and $78). It is
unclear from where the specimens originated or when these were
collected, but this butterfly is now mainly restricted to ENP. The same
Web site offered specimens of Bartram's hairstreak for [euro]10.00
($13). Although the specifics on its collection are not clear, this
butterfly now mainly occurs on protected Federal, State, and County
lands. The same Web site offers specimens of other butterflies similar
in appearance to the Miami blue; the cassius blue is available for
[euro]4.00-10.00 ($5-$13). Additionally, other subspecies of Cyclargus
thomasi that occur in foreign countries are also for sale. It is clear
that a market currently exists for both imperiled species and those
similar in appearance to the Miami blue.
The potential for unauthorized or illegal collection of the Miami
blue (eggs, larvae, pupae, or adults) exists, despite its State-
threatened status and the protections provided on Federal (and State)
land. Illegal collection could occur without detection at remote
islands of KWNWR because these areas are difficult to patrol. The
localized distribution and small population size render this butterfly
highly vulnerable to impacts from collection. At this time, removal of
any individuals may have devastating consequences to the survival of
the subspecies. Although the Miami blue is no longer believed to be
present at BHSP, its return is possible. At BHSP, the butterfly, like
other wildlife and plant species within the Florida park system, is
protected from unauthorized collection (Chapter 62 D-2.013(5)) (see
Factor D). However, because BHSP is so heavily used, continual
monitoring for illegal collections is a challenge. Daniels (pers. comm.
2002) believed that additional patrols would be helpful because
unauthorized collection of specimens is possible, even though
collection is prohibited. In addition, any colonies that might be found
or become established outside of BHSP or other protected sites would
also not be patrolled and would be at risk of collection.
Although the Miami blue's status as a State-threatened species
provides some protection, this protection does not include provisions
for other species of blues that are similar in appearance. Therefore,
it is quite possible that collectors authorized to collect similar
species may inadvertently (or purposefully) collect the Miami blue
butterfly thinking it was, or planning to claim they thought it was,
the cassius blue, nickerbean blue, or ceraunus blue, which can also
occur in the same general geographical area and habitat type. Federal
listing of other similar butterflies can partially reduce this threat
(see Similarity of Appearance below) and provide added protective
measures for the Miami blue above those afforded by the State.
In summary, due to the few metapopulations, small population size,
restricted range, and remoteness of occupied habitat, we have
determined that collection is a significant threat to the subspecies
and could potentially occur at any time. Even limited collection from
the small population in KWNWR (or other populations, if discovered)
could have deleterious effects on reproductive and genetic viability
and thus could contribute to its extinction.

Scientific Research and Conservation Efforts

Some techniques (e.g., capture, handling) used to understand or
monitor the Miami blue have the potential to cause harm to individuals
or habitat. Visual surveys, transect counts, and netting for
identification purposes have been performed during scientific research
and conservation efforts with the potential to disturb or

[[Page 20972]]

injure individuals or damage habitat. Mark-recapture, a common method
used to determine population size, has been used by some researchers to
monitor Miami blue populations. This method has received some
criticism. While mark-recapture may be preferable to other sampling
estimates (e.g., count-based transects) in obtaining demographic data
when used in a proper design on appropriate species, such techniques
may also result in deleterious impacts to captured butterflies (Mallet
et al. 1987, pp. 377-386; Murphy 1988, pp. 236-239; Haddad et al. 2008,
pp. 929-940). Although effects may vary depending upon taxon,
technique, or other factors, some studies suggest that marking may
damage or kill butterflies or alter their behaviors (Mallet et al.
1987, pp. 377-386; Murphy 1988, pp. 236-239). Murphy (1988, p. 236) and
Mattoni et al. (2001, p. 198) indicated that studies on various
lycaenids have demonstrated mortality and altered behavior as a result
of marking. Conversely, other studies have found that marking did not
harm individual butterflies or populations (Gall 1984, pp. 139-154;
Orive and Baughman 1989, p. 246; Haddad et al. 2008, p. 938). No
studies have been conducted to determine the potential effects of
marking on the Miami blue. Although data are lacking, researchers
permitted to use such techniques have been confident in their abilities
to employ the techniques safely with minimal effect on individuals
handled. Researchers currently studying the population within KWNWR
have opted not to use mark-release-recapture techniques due to the
potential for damage to this small, fragile butterfly (Haddad and
Wilson 2011, p. 3).
Captive propagation and reintroduction activities may present risks
if wild populations are impacted or if the species is introduced to new
or inappropriate areas outside of its historical range (65 FR 56916-
56922, September 20, 2000). Although butterflies were successfully
reared in captivity at the UF with the support of State and Federal
agencies, efforts to reintroduce the Miami blue to portions of its
historical range did not result in the establishment of any new
populations (Emmel and Daniels 2009, pp. 4-5; FWC 2010, p. 8). While
some monitoring occurred following releases, it is not clear why
captive-reared individuals did not persist in the wild. Perhaps
experiments using surrogate species (e.g., other lycaenids) and more
structured and intense monitoring following releases can help elucidate
possible causes for failure and improve chances for reestablishment in
the future.
Declines in the captive colony in 2005 and 2006 were attributed to
a baculovirus; consequently, this captive colony was terminated after
30 generations and another was started with new stock from BHSP
(Saarinen 2009, p. 92). Baculovirus infections are capable of
devastating both laboratory and wild butterfly populations (Saarinen
2009, pp. 99, 119). Irrevocable consequences may occur if a pathogen is
transferred from laboratory-reared to wild populations. Genetic
diversity within the captive colony was lost over time (between
generations) (Saarinen 2009, p. 100). At one point, the captive colony
was not infused with new genetic material for approximately 1 year due
to low numbers within the wild population. As a result, decreases in
genetic diversity, allelic richness, and number of individuals produced
occurred during this time (Saarinen 2009, p. 100). While captive
propagation and reintroduction efforts offer enormous conservation
potential, there can be associated risks and ramifications to both wild
and captive-reared individuals and populations.
The use of captive-reared Miami blues in pesticide-use and life-
history studies can be questioned and has been criticized by some (FWC
2010, p. 10). All experiments were conducted with captive-reared
individuals; no wild individuals were used. Individuals used in
experiments were not intended for release back into the wild or were
reared specifically for this purpose. Researchers involved with the
captive colony and others conducting scientific studies or other
conservation efforts were authorized by appropriate agencies to conduct
such work.

Summary of Factor B

Collection interest of imperiled butterflies is high, and there are
ample examples of collection pressure contributing to extirpations.
Although we do not have information indicating that Miami blues are
being collected, we consider collection to be a significant threat to
the subspecies due to the few remaining metapopulations, small
population size, restricted range, and remoteness of occupied habitat,
and because collection could potentially occur at any time. Even
limited collection from the remaining metapopulation could have
deleterious effects on reproductive and genetic viability of the
subspecies and could contribute to its extinction.
Captive propagation and reintroduction may be important components
of the subspecies' survival and recovery, but such actions need to be
carefully planned, implemented, and monitored. Any future efforts
should only be initiated after it has been determined that such actions
will not harm the wild population, rigorous standards are met, and
commitments are in place to increase the likelihood of success and
maximize knowledge gained.
Based on our analysis of the best available information, there is
no evidence to suggest that its vulnerability to collection and risks
associated with scientific or conservation efforts will change in the
future.
C. Disease or Predation
The effects of disease or predation are not well known. Because the
Miami blue is known from only a few locations and population size
appears low, disease and predation could pose a threat to its survival.

Disease

A baculovirus was confirmed within the captive colony, and
infection caused the death of Miami blue larvae in captivity (see
Factor B above) (Saarinen 2009, p. 120). Pathogens have affected other
insect captive-breeding programs, however, this was the first time a
baculovirus was found to affect a captive colony of an endangered
Lepidopteran (Saarinen 2009, p. 120). A baculovirus or other disease or
pathogens have the potential to destroy wild populations (Saarinen
2009, p. 99). Nice et al. (2009, p. 3137) identified widespread
infection from the endosymbiotic bacterial Wolbachia within western
populations of the endangered Karner blue (Lycaeides samuelis) and
indicated the bacteria may also pose a significant threat towards other
endangered arthropods. Plant pathogens could also negatively impact
host plant survival, host growth, or the production of terminal host
growth available to developing larvae (Emmel and Daniels 2004, p. 14).
At this time, there is no information to suggest that disease or
pathogens are affecting Miami blue butterflies or host plants in the
wild.

Predation

Predation of adults or immature stages was not observed during
monitoring at BHSP, despite the presence of potential predators (Emmel
and Daniels 2004, p. 12; Trager 2009, p. 152). Several species of
social wasps, specifically paper wasps (Polistes) and yellow jackets
(Vespula), are known to depredate Lepidoptera on nickerbean and
surrounding vegetation at BHSP and other sites with suitable habitat,
but

[[Page 20973]]

predation on Miami blue larvae was not observed (Trager 2009, p. 152).
Carroll and Loye (2006, p. 18) encountered a parasitic wasp,
Lisseurytomella flava, during their studies of the balloonvine insects
on northern Key Largo during the late 1980s. No wasp parasitism towards
Miami blue larvae was noted (Carroll and Loye 2006, p. 24). However,
this wasp, along with the Miami blue, was absent from continued
balloonvine sampling in 2003, suggesting the wasp may have used the
butterfly as host.
Cannon et al. (2007, p. 16) observed wasps (unidentified) eating
Miami blue larvae at KWNWR; wasps and dragonflies were also observed to
chase adults in flight. Adult Miami blues were found entrapped in the
webs of silver orb spiders (Argiope argentata) (Cannon et al. 2007, p.
16). Trager (2009, pp. 149, 153-154) indicated that the Miami blue is
likely depredated under natural conditions, but only predation by an
adult brown anole lizard (Anolis sagrei) was observed during field
studies. Iguanas likely consume eggs and pupae when opportunistically
feeding on host plants (P. Hughes, pers. comm. 2009; Daniels 2009, p.
5; FWC 2010, p. 13), especially since the butterfly uses the same
terminal growth of host plants that iguanas typically eat (see Factor
E). Predators and parasitoids have been suggested as potential
contributors to the butterfly's decline (M. Minno, pers. comm. 2010),
but this has not been observed or confirmed in the field (Trager 2009,
p. 149; Minno and Minno 2009, p. 78; FWC 2010, pp. 13, 24).
The extent to which native or exotic ants and other predators and
parasitoids may pose a threat to the Miami blue is not clear, but
deserves further attention. For example, invasive fire ants (Solenopsis
invicta) were first confirmed in counties within the historical range
of the Miami blue as early as 1958 (Hillsborough); presence was
confirmed in additional counties in the late 1960s (Brevard and
Volusia) and 1970s (Broward, Collier, Miami-Dade, Lee, Monroe)
(Callcott and Collins 1996, p. 249); infestation has since expanded. In
addition to the possible direct effects of predation, fire ants can
also disrupt arthropod communities and displace native ants. In one
study, Porter and Savignano (1990, pp. 2095-2106) found that S. invicta
reduced species richness by 70 percent and abundance of native ants by
90 percent.
Both the red imported fire ant and the little fire ant (Wasmannia
auropunctata), another invasive exotic ant, currently occur at BHSP
(Saarinen and Daniels 2006, p. 71). Fire ants have also been found on
all beaches within KWNWR (Wilmers et al. 1996, pp. 341-343; Wilmers
2011, pp. 20-21; T. Wilmers, pers. comm. 2012a). In one study in Key
Largo, fire ants were found within half of the study transects and in
close proximity to the edge of hardwood hammock habitat (Forys et al.
2001, p. 257). Forys et al. (2001, p. 257) found all immature
swallowtail life stages to be vulnerable to predation by imported fire
ants and recognized the potential impact of this predatory insect on
the federally endangered Schaus swallowtail and other butterflies in
south Florida. Thus, immature life stages of the Miami blue may be
vulnerable to predation by fire ants within its current known locations
or if the butterfly still persists, elsewhere in its historical range.
In a greenhouse situation, Trager (2009, p. 151) observed fire ants
removing Miami blue eggs in an indoor flight cage, but noted that the
ants did not attack larvae on the same plant. In his studies, a captive
colony of fire ants was found to consume captive-reared Miami blue
pupae in food trays; however, the ants did not remove newly laid eggs
from the host plant and even exhibited weak tending behavior toward
larvae (Trager 2009, pp. 151-152). At this time, it is unclear to what
extent native and exotic predatory insects may be impacting wild Miami
blue populations.
Some ant species may also protect Miami blue larvae against
parasitoids and predators; however, this has not yet been observed in
the wild (Trager and Daniels 2009, 479; Trager 2009, p. 101). In
laboratory studies, Camponotus floridanus ants have been shown to
display strong defensive behaviors (e.g., rapidly circling larvae,
recruiting nearby workers, and lunging at forceps) when disturbed
(Trager and Daniels 2009, p. 480; Trager 2009, p. 102). The large size
of this ant species and nearly constant tending may serve as a visual
deterrent to potential attackers; however, researchers acknowledged
that they have no definitive evidence that C. floridanus are more
effective defenders of Miami blue larvae than small-bodied ant species
(Trager and Daniels 2009, p. 480; Trager 2009, p. 97).
Researchers have suggested that some ant species may depredate
Miami blue larvae or may opportunistically tend larvae without
providing protection against predators or other benefits (Saarinen and
Daniels 2006, p. 73; Saarinen 2009, pp. 134, 138). However, Trager and
Daniels (2009, pp. 478-481) recorded a universal tending response among
ants consistent with a mutualistic interaction through both field
observations and laboratory trials. They did not observe any
depredation of larvae by ants in the field and, based upon
observations, doubted that many ant species regularly depredate larvae
(Trager and Daniels 2009, pp. 479-481; Trager 2009, p. 149).

Summary of Factor C

Studies suggest that various stressors (e.g., baculovirus, fire
ants) have the potential to negatively impact the Miami blue, but there
is no information on their impacts to wild populations. The Miami blue
may have some mechanisms to potentially deter predators and
parasitoids, but these are not well understood. The role of predation
and parasitism needs to be more closely examined. Disease and predation
have the potential to impact the Miami blue's continued survival, given
its few remaining populations, low abundance, and restricted range.
However, we do not have information to suggest that disease and
predation are threats to the Miami blue at this time.
D. The Inadequacy of Existing Regulatory Mechanisms
Despite the fact that they contain several protections for the
Miami blue, Federal, State, and local laws have not been sufficient to
prevent past and ongoing impacts to the Miami blue and its habitat
within its current and historical range.
In response to a petition from the NABA in 2002, the FWC emergency-
listed the Miami blue butterfly in 2002, temporarily protecting the
butterfly. On November 19, 2003, the FWC declared the Miami blue
butterfly endangered (68A-27.003), making its protection permanent. On
November 8, 2010, the FWC adopted a revised listing classification
system, moving from a multi-tiered to single-category system. As a
consequence of this change, the Miami blue butterfly (along with other
species) became State-threatened; its original protective measures
remained in place (68A-27.003, amended). This designation prohibits any
person from taking, harming, harassing, possessing, selling, or
transporting any Miami blue or parts thereof or eggs, larvae or pupae,
except as authorized by permit from the executive director, with
permits issued based upon whether issuance would further management
plan goals and objectives. Although these provisions prohibit take of
individuals, there is a general lack of law enforcement presence in
many areas. In addition, existing regulations prohibit take, but do not
provide substantive protection of Miami blue habitat or protection of
potentially suitable habitat. Therefore, while the Miami blue butterfly
is afforded some protection by its presence

[[Page 20974]]

on Federal (and State) lands, losses of suitable and potential habitat
outside of these areas are expected to continue (see Factor A).
The Miami blue's presence on Federal (and State) lands offers some
insulation against collection, but protection is somewhat limited (see
Factor B). Permits are necessary for authorized collection, but law
enforcement presence on Federal and State land is often inadequate. In
addition, many areas are difficult to patrol and the State's protection
of the Miami blue does not extend to butterflies that are similar in
appearance (see Similarity of Appearance below). Because there are only
slight morphological differences between the Miami blue and other
butterfly species in the same areas, the Miami blue remains at risk to
illegal collection, despite the regulatory mechanisms already in place
(see Factor B).
As a Federal candidate subspecies, the Miami blue was afforded some
protection through sections 7 and 10 of the Act and associated policies
and guidelines, but protection was limited. Federal action agencies are
to consider the potential effects to the butterfly and its habitat
during the consultation process. Applicants and action agencies are
encouraged to consider candidate species when seeking incidental take
for other listed species and when developing habitat conservation
plans. On Federal lands, such as KWNWR, candidate species are treated
as ``proposed threatened.''
Although the Miami blue occurs on Federal (and possibly State) land
that offers protection, these areas are vast and often heavily used.
Signage prohibiting collection is sometimes lacking or may not be
advisable as it could draw attention to the presence of the subspecies;
patrolling and monitoring of activities can be limited and dependent
upon the availability of staffing and resources. Within KWNWR, the
Marquesas Keys are open to the public; portions of the beach on Boca
Grande are closed (T. Wilmers, pers. comm. 2011b). In general, occupied
islands are remote and difficult to patrol, and trespassing and
unauthorized uses (e.g., fire and fire pits) still occur (see Factor
E). Therefore, the potential for illegal collection and damage to
sensitive habitats still exists (see Factors B and E).
Prior to its apparent extirpation, the metapopulation at BHSP was
afforded some protection by its presence on State lands. All property
and resources owned by FDEP are generally protected from harm in
Chapter 62D-2.013(2), and animals are specifically protected from
unauthorized collection in Chapter 62D-2.013(5) of the Florida
Statutes. Exceptions are made for collecting permits, which are issued,
``for scientific or educational purposes.'' Still, protection of
resources at BHSP is a challenge due to the park's popularity and high
use (See Factor E). Although in 2010, the FDEP hired a temporary, full-
time biologist to work on Miami blue conservation issues at BHSP,
including patrol of sensitive habitats, this position has since been
reduced to part-time.
Permits are required from the FWC for scientific research on and
collection of the Miami blue. For work on Federal lands (i.e., KWNWR,
ENP, and BNP), permits are required from the Service or the NPS. For
work on State lands, permits are required from FDEP. Permits are also
required for work on County-owned lands.

Summary of Factor D

Despite existing regulatory mechanisms, the Miami blue continues to
decline due to the effects of a wide array of threats (see Factors A,
B, and E). Based on our analysis of the best available information, we
find that existing regulatory measures, due to a variety of
constraints, do not work as designed, and, therefore, the existing
regulatory mechanisms are inadequate to address threats to the
subspecies throughout all of its range. We have no information to
indicate that the aforementioned regulations, which currently do not
offer adequate protection to the Miami blue, will be revised such that
they would be adequate to provide protection for the subspecies in the
future.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Impacts From Iguanas
The exotic green iguana (Iguana iguana) appears to be a severe
threat to the Miami blue (75 FR 69258; Daniels 2009, p. 5; FWC 2010,
pp. 6, 13; Olle 2010, pp. 4, 14). Iguanas are prevalent within the
Keys, and sightings within occupied and potential Miami blue habitat
are common (P. Cannon, pers. comm. 2009, 2010d, 2010e). Effects of
iguana herbivory to the host plant (nickerbean) at BHSP were evident by
late 2008 and early 2009 (Emmel and Daniels 2009, p. 4; Daniels 2009,
p. 5; P. Hughes, pers. comm. 2009; P. Cannon, pers. comm. 2009; A.
Edwards, pers. comm. 2009). In January 2009, Cannon (pers. comm. 2009)
reported that iguanas had stripped all new nickerbean growth, causing
substantial losses since November 2008. In April 2009, nickerbean
showed signs of limited growth due to chronic herbivory (P. Hughes,
pers. comm. 2009).
In addition to damage, iguanas likely consume eggs and pupae when
opportunistically feeding (P. Hughes, pers. comm. 2009; Daniels 2009,
p. 5; FWC 2010, p. 13), especially since the butterfly uses the same
terminal growth of host plants to lay eggs. For many years, host plant
abundance within BHSP appeared capable of sustaining both iguanas and
Miami blues. Depressed numbers of Miami blues in 2008, however, were
likely the result of both a severe drought and impacts to the
nickerbean from iguanas feeding on the terminal nickerbean growth (FWC
2010, p. 6). During the winter of 2010, prolonged and unseasonably cold
temperatures in the lower Keys resulted in a considerable decline in
available nickerbean at BHSP (Olle 2010, p. 14). The suppressed Miami
blue population at this site during this time may not have been able to
survive this temporary, but severe, reduction in nickerbean, likely
caused by the combined influences of iguanas and environmental factors
(e.g., drought and cold).
Iguana tracks have been found on islands occupied by the Miami blue
in KWNWR (Cannon et al. 2007, p. 16; T. Wilmers, pers. comm. 2011c) as
well as on three islands in GWHNWR (T. Wilmers, pers. comm. 2011b).
Three large, gravid female iguanas were trapped and removed from the
Marquesas in February 2011 (T. Wilmers, pers. comm. 2011d). To date,
the presence of iguanas (burrows or tracks) has been documented on each
of the islands known to harbor Miami blues (T. Wilmers, in litt.
2011e). Cannon et al. (2007, p. 16) stated that the exotic herbivore
has the potential to impact host and nectar plants. Iguana populations
in south Florida, after long periods of slow growth, have been shown to
irrupt (increase suddenly or rapidly in numbers) (Meshaka et al. 2004,
pp. 157-158; Meshaka 2011, p. 52). Given the absence of predators
within KWNWR, the iguana population may grow unchecked until limited by
food sources or other natural factors (e.g., hurricanes). A further
concern is that severe damage to vegetation, as occurred during
Hurricane Wilma (Cannon et al. 2010, p. 851), may concentrate Miami
blues and iguanas in remnant stands of blackbead, thereby magnifying
the iguana's impact on the butterfly and its habitat (T. Wilmers, in
litt. 2011e).
Resource agencies are working to better understand and combat the
threat of green iguanas in areas occupied (and

[[Page 20975]]

recently occupied) by the Miami blue. At BHSP, cooperative efforts
resulted in the trapping and removal of 200 iguanas between November
2009 and October 2011 (Emmel and Daniels 2009, p. 4; FWC 2010, p. 17;
E. Kiefer, pers. comm. 2011a, 2011b; E. Cowan, FPS, pers. comm. 2011).
Removal efforts have significantly decreased the number of iguanas
within BHSP; these management actions will need to be an ongoing effort
due to the prevalence of iguanas in the surrounding areas (R. Zambrano,
pers. comm. 2009; E. Cowan, pers. comm. 2011). Efforts are also
underway to assess and address this threat at KWNWR, but it is unclear
if iguanas regularly consume blackbead at the Refuge (T. Wilmers, pers.
comm. 2011a, 2011c, 2011d, 2011f). Despite cooperative efforts, the
threat from iguanas is expected to continue due to their widespread
distribution and the difficulties in control.

Competition

Host resource competition from other butterfly species could
deleteriously impact metapopulation productivity of the Miami blue. The
introduction of or future island colonization by potential Lepidopteran
competitors may impact the Miami blue metapopulation. The nickerbean
blue, cassius blue, and Martial's scrub hairstreak are known to use
various species of nickerbean host plants throughout their range
(Glassberg et al. 2000, pp. 74-80; Calhoun et al. 2002, p. 15). The
nickerbean blue and Martial's scrub hairstreak have been documented
using gray nickerbean as a host plant at BHSP (Daniels et al. 2005, p.
174; P. Cannon, pers. comm. 2010g). Such host use may represent direct
competition for host resources (Emmel and Daniels 2004, p. 14).
However, Calhoun et al. (2002, p. 18) believed it was unlikely that
competition played a significant role in the decline of the Miami blue
based on the abundance of host plant sources available to lycaenids
throughout the Lower Keys. There is no evidence to suggest that host
resource competition is a threat to the Miami blue at this time or is
likely to become so in the future.

Inadvertent and Purposeful Impacts From Humans

Inadvertent damage from humans can affect the Miami blue and its
habitat in its current and former range. For example, the seed pods of
balloonvine ``pop'' when squeezed and can be targeted by humans. Damage
to balloonvine has been documented along roads in the Keys (J. Loye,
University of California-Davis, pers. comm. 2003a, 2003b). During a
study in the mid-1980s examining balloonvine and its associated insect
community, Loye (pers. comm. 2003a) found a difference in insect
diversity between sites along roads and those without road access.
Acknowledging other possible contributing factors (e.g., mosquito
control, car emissions), Loye (pers. comm. 2003a) indicated that
collectors and maintenance crews damaged balloons near roads, stating
that ``humans damaged every balloon that could be easily found at our
study sites'' (J. Loye, pers. comm. 2003b). It is not clear what, if
any, impact this had on the butterfly at or since that time. However,
damage to host plants (whole or parts) could contribute to mortality of
eggs or larvae.
BHSP is heavily used by the public for recreational purposes, and
although the butterfly has not been seen at this location since early
2010, suitable habitat is located along trails and other high-use areas
(e.g., campgrounds). Former colonies may have experienced disturbance
from Park visitors. Trampling of host plants and well-worn footpaths
were evident, at least periodically from 2002 to 2010, and during times
when other stressors (e.g., cold, drought, iguanas) occurred (P.
Halupa, pers. obs. 2002; D. Olle, pers. comm. 2010; M. Salvato, pers.
comm. 2010a; R. Zambrano, pers. comm. 2010). To protect larval host
plants and adult nectar sources, the FPS erected fencing and signage
around the majority of the south colony site at BHSP. Although this is
expected to minimize damage to the largest habitat patch, other small
habitat patches (as small as 15.0 by 15.0 feet [4.6 by 4.6 meters])
elsewhere on the island are still vulnerable to intentional or
accidental damage. Fencing small colony sites or patches of available
habitat is impractical and would make exact locations of colonies more
evident, possibly increasing the risk of illegal collection or harm
should the Miami blue return to the island.
KWNWR lacks human developments, but local disturbances result from
illicit camping, fire pits, smugglers, vandals, and immigrant landings.
These disturbances are generally infrequent for most islands within
KWNWR with the exception of Boca Grande, which contains the largest
amounts of beach. Recreational visitation is high on Boca Grande,
particularly during weekends (Cannon et al. 2010, p. 852). Trampling of
dune vegetation has been a long-term problem on Boca Grande, and fire
pits have been found many times over the past two decades on both Boca
Grande and the Marquesas Keys (Cannon et al. 2010, p. 852). Most
recently, a fire pit was found adjacent to host plants within occupied
habitat on Boca Grande in December 2011 (P. Cannon, pers. comm. 2012).
The large amount of dead vegetation intermingled with host plants on
Boca Grande and the Marquesas Keys makes the threat of fire (natural or
human-induced), a significant threat to the Miami blue (Cannon et al.
2007, p. 13; 2010, p. 852; P. Cannon, pers. comm. 2012; T. Wilmers,
pers. comm. 2012b). Immature stages (eggs, larvae), which are
sedentary, would be particularly vulnerable. Glassberg and Olle (2010,
p. 1) asserted that ``the proximity of the islands within KWNWR, to
both Key West and the Dry Tortugas, invite human mischief, and largely
go unpoliced.'' These areas within KWNWR are remote and accessible
mainly by boat, making them difficult to patrol and monitor.
Other patches of potential and suitable habitat are susceptible to
purposeful impacts from humans. Some private property owners in the
Keys have reportedly threatened to clear vegetation from undeveloped
properties to avoid any restrictions regarding the butterfly (M. Minno,
in litt. 2011b; N. Pakhomoff-Spencer, consultant, pers. comm. 2011).
In summary, inadvertent and purposeful impacts from humans may have
affected the Miami blue and its habitat. Due to the location of
occupied and suitable habitat, the popularity of these areas with
humans, and the projected human growth, especially in coastal areas,
such impacts from recreation and other uses are expected to continue.

Other Natural and Unnatural Changes to Habitat

Natural changes to vegetation from environmental factors,
succession, or other causes may now be a threat to the Miami blue
because of its severely reduced range, few populations, and limited
dispersal capabilities. Suitable and occupied habitat in KWNWR and
other coastal areas is dynamic and fluctuating, influenced by a variety
of environmental factors (e.g., storm surge, wind, precipitation). In
2010, substantial changes in habitat conditions on Boca Grande occurred
with the proliferation of Galactia striata, a native climbing vine (T.
Wilmers, pers. comm. 2010a; P. Cannon, pers. comm. 2010b, 2010h, 2010i,
2010j). The vine has enveloped a substantial amount of blackbead,
occurring on about 40 percent of the blackbead growing on the seaward
side at the dune interface (T. Wilmers, pers. comm. 2010a). Wilmers
(pers. comm. 2010a) indicated that the extensive growth was likely
fueled by the markedly higher

[[Page 20976]]

precipitation during September and October 2010 (3.47 and 2.22 inches
[8.81 and 5.64 cm], respectively, above normal in Key West). Under
favorable conditions, the vine first grows in the dune, then sprawls
landward laterally, eventually ascending and blanketing blackbead (T.
Wilmers, pers. comm. 2010a). While climbing vines can proliferate
before eventually dying back, Wilmers (pers. comm. 2010a) stated that
the intense proliferation in 2010 was unprecedented in his 25 years of
work in the area. Left unchecked, this proliferation has the potential
to impact host plants and affect the butterfly's ability to persist on
some islands.

Invasive and Exotic Vegetation

Displacement of native plants including host plants by invasive
exotic species, a common problem throughout south Florida, also
possibly contributed to habitat loss of the Miami blue. In coastal
areas where undeveloped land remains, the Miami blue's larval food
plants are likely to be displaced by invasive exotic plants, such as
Brazilian pepper, Australian pine (Casuarina equesitifolia), Asian
nakedwood (Colubrina asiatica), cat-claw vine (Macfadyena ungius-cati),
wedelia (Spahneticola trilobata), largeleaf lantana (Lantana camara),
Portia tree (Thespesia populnea), wild indigo (Indigofera spicata),
beach naupaka (Scaevola taccada), and several species of invasive
grasses. Although we do not have direct evidence of exotic species
displacing host plants or nectar sources, we recognize this as a
potential threat, due to the magnitude of this problem in south
Florida.

Pesticides

Efforts to control salt marsh mosquitoes, Aedes taeniorhynchus,
among others, have increased as human activity and population have
increased in south Florida. To control mosquito populations, second-
generation organophosphate (naled) and pyrethroid (permethrin)
adulticides are applied by mosquito control districts throughout south
Florida. In a rare case in upper Key Largo, another organophosphate
(malathion) was applied in 2011 when the number of permethrin
applications reached its annual limit. All three of these compounds
have been characterized as being highly toxic to nontarget insects by
the U.S. Environmental Protection Agency (2002, p. 32; 2006a, p. 58;
2006b, p. 44). The use of such pesticides (applied using both aerial
and ground-based methods) to control mosquitoes presents a potential
risk to nontarget species, including the Miami blue butterfly.
The potential for mosquito control chemicals to drift into
nontarget areas and persist for varying periods of time has been well
documented. Hennessey and Habeck (1989, pp. 1-22; 1991, pp. 1-68) and
Hennessey et al. (1992, pp. 715-721) illustrated the presence of
mosquito spray residues long after application in habitat of the Schaus
swallowtail and other imperiled species in both the upper (Crocodile
Lake NWR, North Key Largo) and lower Keys (NKDR). Residues of aerially
applied naled were found 6 hours after application in a pineland area
that was 820 yards (750 meters) from the target area; residues of
fenthion (an adulticide no longer used in the Keys) applied via truck
were found up to 55 yards (50 meters) downwind in a hammock area 15
minutes after application in adjacent target areas (Hennessey et al.
1992, pp. 715-721).
More recently, Pierce (2009, pp. 1-17) monitored naled and
permethrin deposition following application in and around NKDR from
2007 to 2009. Permethrin, applied by truck, was found to drift
considerable distances from target areas with residues that persisted
for weeks. Naled, applied by plane, was also found to drift into
nontarget areas but was much less persistent, exhibiting a half-life of
approximately 6 hours. To expand this work, Pierce (2011, pp. 6-11)
conducted an additional deposition study in 2010 focusing on permethrin
drift from truck spraying and again documented measurable amounts of
permethrin in nontarget areas. In 2009, Tim Bargar (pers. comm. 2011)
conducted two field trials on NKDR that detected significant naled
residues at locations within nontarget areas on the Refuge that were up
to 440 yards (402 meters) from the edge of zones targeted for aerial
applications.
In addition to mosquito control chemicals entering nontarget areas,
the toxic effects of mosquito control chemicals to nontarget organisms
have also been documented. Lethal effects on nontarget Lepidoptera have
been attributed to fenthion and naled in both south Florida and the
Keys (Emmel 1991, pp. 12-13; Eliazar and Emmel 1991, pp. 18-19; Eliazar
1992, pp. 29-30). In the lower Keys, Salvato (2001, pp. 8-14) suggested
that declines in populations of the Florida leafwing (now a Federal
candidate) were also partly attributable to mosquito control chemical
applications. Salvato (2001, p. 14; 2002, pp. 56-57) found populations
of the Florida leafwing (on Big Pine Key within NKDR) to increase
during drier years when adulticide applications over the pinelands
decreased, although Bartram's hairstreak did not follow this pattern.
It is important to note that vulnerability to chemical exposure may
vary widely between species, and current application regimes do not
appear to affect some species as strongly as others (Calhoun et al.
2002, p. 18; Breidenbaugh and De Szalay 2010, pp. 594-595; Rand and
Hoang 2010, pp. 14-17, 20; Hoang et al. 2011, pp. 997-1005).
Dose-dependent decreases in brain cholinesterase activity in great
southern white butterflies (Ascia monuste) exposed to naled have been
measured in the laboratory (T. Bargar, pers. comm. 2011). An inhibition
of cholinesterase, which is the primary mode of action of naled,
prevents an important neurotransmitter, acetylcholine, from being
metabolized, causing uncontrolled nerve impulses that may result in
erratic behavior and, if severe enough, mortality. From these data, it
was determined that significant mortality was associated with
cholinesterase activity depression of at least 27 percent (T. Bargar,
pers. comm. 2011). In a subsequent field study on NKDR, adult great
southern white and Gulf fritillary (Agraulis vanillae) butterflies were
placed in field enclosures at both target and nontarget areas during
aerial naled application. The critical level of cholinesterase
inhibition (27 percent) was exceeded in the majority of butterflies
from the target areas, as well as in a large proportion of butterflies
from the nontarget areas (T. Bargar, pers. comm. 2011). During the same
field experiment, great southern white and Gulf fritillary larvae were
also exposed in the field during aerial naled application and exhibited
mortality at both target and nontarget sites (T. Bargar, pers. comm.
2011).
In a laboratory study, Rand and Hoang (2010, pp. 1-33) and Hoang et
al. (2011, pp. 997-1005) examined the effects of exposure to naled,
permethrin, and dichlorvos (a breakdown product of naled) on both
adults and larvae of five Florida native butterfly species (common
buckeye (Junonia coenia), painted lady (Vanessa cardui), zebra longwing
(Heliconius charitonius), atala hairstreak (Eumaeus atala), and white
peacock (Anartia jatrophae). The results of this study indicated that,
in general, larvae were slightly more sensitive to each chemical than
adults, but the differences were not significant. Permethrin was
generally the most toxic chemical to both larvae and adults, although
the sensitivity between species varied.
The laboratory toxicity data generated by this study were used to
calculate hazard quotients (concentrations in the environment/
concentrations causing an

[[Page 20977]]

adverse effect) to assess the risk that concentrations of naled and
permethrin found in the field pose to butterflies. A hazard quotient
that exceeds one indicates that the environmental concentration is
greater than the concentration known to cause an adverse effect
(mortality in this case), thus indicating significant risk to the
organism. Environmental exposures for naled and permethrin were taken
from Zhong et al. (2010, pp. 1961-1972) and Pierce (2009, pp. 1-17),
respectively, and represent the highest concentrations of each chemical
that were quantified during field studies in the Keys. When using the
lowest median lethal concentrations from the laboratory study, the
hazard quotients for permethrin were greater than one for each adult
butterfly, indicating a significant risk of toxicity to each species.
In the case of naled, significant risk to the zebra longwing was
predicted based on its hazard quotient exceeding one.
In a recent study, Bargar (2012, pp. 1-7) conducted a probabilistic
risk assessment for adult butterflies using published acute toxicity
data in combination with deposition values for naled that were
quantified at eight locations within NKDR. The published toxicity data
were used in conjunction with morphometric data (total surface area and
weight) for 22 butterfly species and the NKDR naled deposition values
to estimate the probability that field exposure to naled will exceed
butterfly effect estimates (quantity of naled per unit body weight
associated with mortality in adult butterflies). From the field
deposition measurements, the probability that the effect estimate for
50 percent of the examined butterfly species will be exceeded ranged
from 70 (lowest butterfly surface area to weight ratio) to 95 percent
(highest surface area to weight ratio) based on filter paper deposition
results and 33 to 87 percent based on yarn sampler results. As the
surface area to weight ratio increases, the probability that a greater
quantity of naled per unit body weight will be delivered increases.
These results suggest that significant impacts on butterfly survival
may result from aerial naled application.
From 2006 to 2008, Zhong et al. (2010, pp. 1961-1972) investigated
the impact of single aerial applications of naled on Miami blue larvae
in the field. The study was conducted in North Key Largo in cooperation
with the Florida Keys Mosquito Control District (FKMCD) and used
experimentally placed Miami blue larvae that were reared in captivity.
The study involved 15 test stations: 9 stations in the target zone, 3
stations considered to be susceptible to drift (2 stations directly
adjacent to the spray zone and 1 station 12 mi (19.3 km) southwest of
the spray zone), and 3 field reference stations (25 mi (40.2 km)
southwest of the spray zone). Survival of butterfly larvae in the
target zone was 73.9 percent, which was significantly lower than both
the drift zone (90.6 percent) and the reference zone (100 percent),
indicating that direct exposure to naled poses significant risk to
Miami blue larvae. In addition to observing elevated concentrations of
naled at test stations in the target zone, 9 of 18 samples in the drift
zone also exhibited detectable concentrations, once again exhibiting
the potential for mosquito control chemicals to drift into nontarget
areas.
Based on these studies, it can be concluded that mosquito control
activities that involve the use of both aerial and ground-based
spraying methods have the potential to deliver pesticides in quantities
sufficient to cause adverse effects to nontarget species in both target
and nontarget areas. It should be noted that many of the studies
referenced above dealt with single application scenarios and examined
effects on only one to two butterfly life stages. Under a realistic
scenario, the potential exists for exposure to all life stages to occur
over multiple applications in a season. In the case of a persistent
compound like permethrin where residues remain on vegetation for weeks,
the potential exists for nontarget species to be exposed to multiple
pesticides within a season (e.g., permethrin on vegetation coupled with
aerial exposure to naled).
Aspects of the Miami blue's natural history may increase its
potential to be exposed to and affected by mosquito control pesticides
and other chemicals. For example, host plants and nectar sources are
commonly found at disturbed sites and often occur along roads in
developed areas, where chemicals are applied. Ants associated with the
Miami blue (see Interspecific relationships) may be affected in unknown
ways. Host plant and nectar source availability may also be indirectly
affected through impacts on pollinators. Carroll and Loye (2006, pp.
19, 24) and others (Emmel 1991, p. 13; Glassberg and Salvato 2000, p.
7; Calhoun et al. 2002, p. 18) suggested that the Miami blue butterfly
may be more susceptible to pesticides than perhaps other lycaenids
(e.g., the silver-banded hairstreak) because Miami blue larvae leave
entrance holes open in seed pods to allow access for attending ants.
Ants and larvae of the Miami blue on balloonvine were found to die when
roadside spraying for mosquito control began in late spring, but larvae
of the silver-banded hairstreak (also on balloonvine), who do not leave
entrance holes in seed pods, apparently survived subsequent spraying
(Emmel 1991, p. 13). However, Minno (pers. comm. 2010) argued that
larvae using balloonvine pods would be protected from the effects of
pesticides because the pods have internal partitions and exposure would
be limited due to the size of the entrance hole.
No mosquito control pesticides are used within KWNWR. At BHSP, the
only application of adulticides (permethrin) is occasional truck-based
spraying in the ranger residence areas (E. Kiefer, pers. comm. 2011a).
Mosquito control practices currently pose no risk to the Miami blue
within KWNWR. However, mosquito control activities, including the use
of larvicides and adulticides, are being implemented within suitable
and potential habitat for the Miami blue elsewhere in its range
(Carroll and Loye 2006, pp. 14-15). The findings of Zhong et al. (2010,
pp. 1961-1972) and Pierce (2009, pp. 1-17) along with other studies
suggest that aerial or truck-based applications of mosquito control
chemicals may pose a threat to the Miami blue, if the butterfly exists
in other, unknown locations. Additionally, mosquito control practices
potentially may limit expansion of undocumented populations or
colonization of new areas. If the Miami blue colonizes new areas or if
additional populations are discovered or reintroduced, adjustments in
mosquito control (and other) practices may be needed to help safeguard
the subspecies.
Efforts are already underway by multiple agencies and partners to
seek ways to avoid and minimize impacts to the Miami blue and other
imperiled nontarget species. For example, in an effort to reduce the
need for aerial adulticide spraying, the FKMCD is increasing
larviciding activities, which are believed to have less of an
ecological impact on wilderness islands near NKDR and GWHNWR (FKMCD
2009, pp. 3-4). This effort has led to a reduction in area receiving
adulticide treatment on Big Pine Key, No Name Key, and Torch Key (FKMCD
2009, p. 17). Another example is the Florida Coordinating Council on
Mosquito Control (FCCMC), including the Imperiled Species Subcommittee,
which was initially formed to resolve the conflict between mosquito
control spraying and the reintroduction of Miami blues to their
historical range (FWC 2010, p. 9).
The FWC's management plan for the Miami blue also recommended the
use

[[Page 20978]]

of no-spray zones for all pesticides and use of buffers at or around
Miami blue populations and other conservation measures (FWC 2010, pp.
ii-41). However, there are no specific binding or mandatory
restrictions to prohibit such practices or encourage other beneficial
measures. The FWC plan suggested that an aerial no-spray buffer zone of
820 yards (750 meters) be established around Miami blue populations,
where possible, and that buffer zones for truck-based applications of
adulticides also be established (FWC 2010, p. 17). The FCCMC also
recommended that the appropriate width of buffer zones be determined by
future research. The Service is supporting research to characterize
drift from truck-based spraying methods. The data from this study will
aid in better determining appropriate buffer distances around sensitive
areas.
In summary, although substantial progress has been made in reducing
impacts, the potential effects of mosquito control applications and
drift residues remain a threat to the Miami blue. We will continue to
work with the mosquito control districts and other partners and
stakeholders to reduce threats wherever possible.

Effects of Small Population Size and Isolation

The Miami blue is vulnerable to extinction due to its severely
reduced range, small population size, metapopulation structure, few
remaining populations, and relative isolation. In general, isolation,
whether caused by geographic distance, ecological factors, or
reproductive strategy, will likely prevent the influx of new genetic
material and can result in low diversity, which may impact viability
and fecundity (Chesser 1983, pp. 66-77). Extinction risk can increase
significantly with decreasing heterozygosity as was reported for the
Glanville fritillary (Saccheri et al. 1998, pp. 491-494). Distance
between metapopulations and colonies within those metapopulations and
the small size of highly sporadic populations can make recolonization
unlikely if populations are extirpated. Fragmentation of habitat and
aspects of a butterfly's natural history (e.g., limited dispersal,
reliance on host plants) can contribute to and exacerbate threats.
Estimated abundance of the Miami blue is not known, but may number
in the hundreds, and at times, possibly higher. Although highly
dependent on individual species considered, a population of 1,000 has
been suggested as marginally viable for an insect (D. Schweitzer, TNC,
pers. comm. 2003). Schweitzer (pers. comm. 2003) has also suggested
that butterfly populations of less than 200 adults per generation would
have difficulty surviving over the long term. In comparison, in a
review of 27 recovery plans for listed insect species, Schultz and
Hammond (2003, p. 1377) found that 25 plans broadly specified
metapopulation features in terms of requiring that recovery include
multiple population areas (the average number of sites required was
8.2). The three plans that quantified minimum population sizes as part
of their recovery criteria for butterflies ranged from 200 adults per
site (Oregon silverspot [Speyeria zerene hippolyta]) to 100,000 adults
(Bay checkerspot [Euphydryas editha bayensis]) (Schulz and Hammond
2003, pp. 1374-1375).
Schultz and Hammond (2003, pp. 1372-1385) used population viability
analyses to develop quantitative recovery criteria for insects whose
population sizes can be estimated and applied this framework in the
context of the Fender's blue (Icaricia icarioides fenderi), a butterfly
listed as endangered in 2000 due to its small population size and
limited remaining habitat. They found the Fender's blue to be at high
risk of extinction at most of its sites throughout its range despite
that fact that the average population at 12 sites examined ranged from
5 to 738 (Schulz and Hammond 2003, pp. 1377, 1379). Of the three sites
with populations greater than a few hundred butterflies, only one of
these had a reasonably high probability of surviving the next 100 years
(Schulz and Hammond 2003, p. 1379). Although the conservation needs and
biology of the Miami blue and Fender's blue are undoubtedly different,
the two lycaenids share characteristics: Both have limited dispersal,
and most remaining habitat patches are completely isolated.
Losses in diversity within historical and current populations of
the Miami blue butterfly have already occurred. Historical populations
were genetically more diverse than two contemporary populations (BHSP
and KWNWR) (Saarinen 2009, p. 48). Yet together, between the two
contemporary populations, the Miami blue had retained a significant
amount of genetic diversity from its historical values (Saarinen 2009,
p. 51). Despite likely fluctuations in population size, the BHSP
population had retained an adequate amount of genetic diversity to
maintain the population (Saarinen 2009, p. 77). Overall, patterns of
genetic diversity in the BHSP population (mean overall observed
heterozygosity of 39.5 percent) were similar to or slightly lower than
other nonmigratory butterfly species studies utilizing microsatellite
markers (Saarinen 2009, pp. 50, 74-75). Unfortunately, the BHSP
population may now be lost. The extant KWNWR population is more
genetically diverse (mean observed heterozygosity of 51 percent vs.
39.5 percent for BHSP) (Saarinen 2009, p. 75).
The Miami blue appears to have been impacted by relative isolation.
No gene flow has occurred between contemporary populations (Saarinen et
al. 2009a, p. 36). Saarinen (2009, p. 79) suggested that the separation
was recent. While historical populations may have once linked the two
contemporary populations, the recent absence of populations between
KWNWR and BHSP appears to have broken the gene flow (Saarinen 2009, p.
79). Based upon modeling with a different butterfly species, Fleishman
et al. (2002, pp. 706-716) argued that factors such as habitat quality
may influence metapopulation dynamics, driving extinction and
colonization processes, especially in systems that experience
substantial natural and anthropogenic environmental variability (see
Environmental Stochasticity below).
According to Saarinen et al. (2009a, p. 36), the severely reduced
size of the existing populations suggests that genetic factors, along
with environmental stochasticity, may already be affecting the
persistence of the Miami blue. However, they also suggested that, in
terms of extinction risk, a greater short-term problem for the two
contemporary natural populations (BHSP and KWNWR) may be the lack of
gene flow rather than the current effective population size (Saarinen
et al. 2009a, p. 36). If only one or two metapopulations remain, it is
absolutely critical that remaining genetic diversity and gene flow are
retained. Conservation decisions to augment or reintroduce populations
should not be made without careful consideration of habitat
availability, genetic adaptability, the potential for the introduction
of maladapted genotypes, and other factors (Frankham 2008, pp. 325-333;
Saarinen et al. 2009a, p. 36).

Aspects of Its Natural History

Aspects of the Miami blue's natural history may increase the
likelihood of extinction. Cushman and Murphy (1993, p. 40) argued that
dispersal is essential for the persistence of isolated populations.
Input of individuals from neighboring areas can bolster dwindling
numbers and provide an influx of genetic diversity, increasing fitness
and population viability. The tendency for

[[Page 20979]]

lycaenids to be comparatively sedentary should result in less frequent
recolonization, less influx of individuals, and reduced gene flow
between populations (Cushman and Murphy 1993, p. 40). In short, taxa
with limited dispersal abilities may be far more susceptible to local
extinction events than taxa with well-developed dispersal abilities
(Cushman and Murphy 1993, p. 40).
Lycaenids with a strong dependence on ants may be more sensitive to
environmental changes and, thus, more prone to endangerment and
extinction than species not tended by ants (and non-lycaenids in
general) (Cushman and Murphy 1993, pp. 37, 41). This hypothesis is
based on the probability that the combination of both the right food
plant and the presence of a particular ant species may occur relatively
infrequently in the landscape. Selection may favor reduced dispersal by
ant-associated lycaenids due to the difficulty associated with locating
patches that contain the appropriate combination of food plants and
ants (Cushman and Murphy 1993, pp. 39-40). Although significant
research on the relationship between Miami blue larvae and ants has
been conducted, this association is still not completely understood.
Lycaenid traits (sedentary, host-specific, symbiotic with ants) that
result in isolated populations of variable sizes may serve to limit
genetic exchange (Cushman and Murphy 1993, pp. 37, 39-40). The Miami
blue possesses several of these traits, all of which may increase
susceptibility and contribute to imperilment.

Environmental Stochasticity

The climate of the Keys is driven by a combination of local,
regional, and global events, regimes, and oscillations. There are three
main ``seasons'': (1) The wet season, which is hot, rainy, and humid
from June through October, (2) the official hurricane season that
extends one month beyond the wet season (June 1 through November 30)
with peak season being August and September, and (3) the dry season,
which is drier and cooler from November through May. In the dry season,
periodic surges of cool and dry continental air masses influence the
weather with short-duration rain events followed by long periods of dry
weather.
Environmental factors have likely impacted the Miami blue and its
habitat within its historical range. A hard freeze in the late 1980s
likely contributed to the Miami blue's decline (L. Koehn, pers. comm.
2002), presumably due to loss of larval host plants in south Florida.
Prolonged cold temperatures in January 2010 and December 2010 through
January 2011 may have also impacted the remaining metapopulations in
the Keys. Unseasonably cold temperatures during winter 2010 (in
combination with impacts from iguanas) resulted in a substantial loss
of nickerbean and nectar sources at BHSP. This reduction, albeit
temporary, may have severely impacted an already depressed Miami blue
population on the island. Similarly, extended dry conditions and
drought can affect the availability of host plants and nectar sources
and affect butterfly populations (Emmel and Daniels 2004, pp. 13-14,
17). Depressed numbers of the Miami blue at BHSP in 2008 were
attributed to severe drought (Emmel and Daniels 2009, p. 4).
The Keys are regularly threatened by tropical storms and
hurricanes. No area of the Keys is more than 20 feet (6.1 meters) above
sea level (and many areas are only a few feet (meters) in elevation).
These tropical systems have affected the Miami blue and its habitat.
Calhoun et al. (2002, p. 18) indicated that Hurricane Andrew in 1992
may have negatively impacted the majority of Miami blue populations in
southern Florida. In 2005, four hurricanes (Katrina, Dennis, Rita, and
Wilma) affected habitat at BHSP, resulting in reduced abundance of
Miami blues following the storms that continued throughout 2006
(Salvato and Salvato 2007, p. 160) and beyond (Emmel and Daniels 2009,
p. 4). A significant portion of the nickerbean and large stands of
nectar plants at BHSP were temporarily damaged by the storms, including
roughly 50 percent of the vegetation on the southern side of the island
(Salvato and Salvato 2007, p. 157). Although the host plant quickly
recovered following the storms (Salvato and Salvato 2007, p. 160), the
Miami blue never fully recolonized several parts of the island (Emmel
and Daniels 2009, p. 4).
Similarly, Hurricane Wilma heavily damaged blackbead across many
islands within KWNWR (Cannon et al. 2010, p. 850). Although the
hurricane severely damaged or killed much of the Miami blue host plant
on KWNWR, it is also believed to have enhanced or created many new
habitats across the islands by clearing older vegetation and opening
patches for growth of host plant and nectar sources (Cannon et al.
2010, p. 852). Cannon et al. (2010, p. 852) suggested that the
proximity and circular arrangement of these islands may provide some
safeguard during mild or moderate storms. Given enough resiliency in
extant populations, certain storm regimes may benefit populations over
some timeframe if these events result in disturbances that favor host
plants and other habitat components.
According to the Florida Climate Center, Florida is by far the most
vulnerable State in the United States to hurricanes and tropical storms
(http://coaps.fsu.edu/climate_center/tropicalweather.shtml). Based on
data gathered from 1856 to 2008, Klotzbach and Gray (2009, p. 28)
calculated the climatological and current-year probabilities for each
State being impacted by a hurricane and major hurricane. Of the coastal
States analyzed, Florida had the highest climatological probabilities,
with a 51 percent probability of a hurricane and a 21 percent
probability of a major hurricane over a 52-year time span. Florida had
a 45 percent current-year probability of a hurricane and an 18 percent
current-year probability of a major hurricane (Klotzbach and Gray 2009,
p. 28). Given the Miami blue's low population size and few isolated
occurrences, the subspecies is at substantial risk from hurricanes,
storm surges, or other extreme weather. Depending on the location and
intensity of a hurricane or other severe weather event, it is possible
that the Miami blue could become extirpated or extinct. Because it
appears to have limited dispersal capabilities, natural recolonization
of potentially suitable sites is anticipated to be unlikely or
exceedingly slow at best.
Other processes to be affected by climate change include
temperatures, rainfall (amount, seasonal timing, and distribution), and
storms (frequency and intensity). Temperatures are projected to rise
from 2 [deg]C to 5 [deg]C (3.6 [deg]F to 9 [deg]F) for North America by
the end of this century (IPCC 2007, pp. 7-9, 13). Based upon modeling,
Atlantic hurricane and tropical storm frequencies are expected to
decrease (Knutson et al. 2008, pp. 1-21). By 2100, there should be a
10-30 percent decrease in hurricane frequency with a 5-10 percent wind
increase. This is due to more hurricane energy available for intense
hurricanes. However, hurricane frequency is expected to drop due to
more wind shear impeding initial hurricane development. In addition to
climate change, weather variables are extremely influenced by other
natural cycles, such as El Ni[ntilde]o Southern Oscillation with a
frequency of every 4-7 years, solar cycle (every 11 years), and the
Atlantic Multi-decadal Oscillation. All of these cycles influence
changes in Floridian weather. The exact magnitude, direction, and
distribution of all of these changes at the regional level are
difficult to project.

[[Page 20980]]

Summary of Factor E
Based on our analysis of the best available information we have
identified a wide array of natural and manmade factors affecting the
continued existence of the Miami blue butterfly. Effects of small
population size, isolation, and loss of genetic diversity are likely
significant threats. Aspects of the Miami blue's natural history and
environmental stochasticity may also contribute to its imperilment.
Other natural (e.g., impacts from iguanas, changes to habitat, invasive
and exotic vegetation) and anthropogenic factors (e.g., pesticides,
habitat alteration, impacts from humans) are also identifiable threats.
Collectively, these threats have operated in the past, are impacting
the subspecies now, and will continue to impact the Miami blue in the
future.

Determination of Status

We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the Miami blue butterfly. The only confirmed metapopulation of Miami
blue is currently restricted to a few, small insular areas in the
extreme southern portion of its historical range. The butterfly's
range, which once extended from the Keys north along the Florida coasts
to about St. Petersburg and Daytona, is now substantially reduced, with
an estimated >99 percent decline in area occupied. Many factors likely
contributed to the Miami blue's decline, and numerous major threats,
acting individually or synergistically, continue today (see Summary of
Factors Affecting the Species).
Habitat loss, degradation, and modification from human population
growth and associated development and agriculture have impacted the
Miami blue, curtailing its range (see Factor A). Environmental effects
from climatic change, especially sea level rise, are expected to become
severe in the future, resulting in additional habitat losses (see
Factor A). Due to the few metapopulations, small population size,
restricted range, and remoteness of occupied habitat, collection is a
significant threat to the subspecies and could potentially occur at any
time (see Factor B). Even limited collection from the remaining
metapopulation could have deleterious effects on reproductive and
genetic viability of the subspecies and could contribute to its
extinction. Similarly, disease and predation (see Factor C) also have
the potential to impact the Miami blue's continued survival, given its
vulnerability (see Factor E).
The subspecies is currently also threatened by a wide array of
natural and manmade factors (see Factor E). In addition to the effects
of small population size, isolation, and loss of genetic diversity,
aspects of the Miami blue's natural history and environmental
stochasticity may contribute to its imperilment. Other natural (e.g.,
impacts from iguanas, changes to habitat) and anthropogenic factors
(e.g., pesticides, impacts from humans) are also threats of varying
magnitude. Finally, existing regulatory mechanisms (see Factor D), due
to a variety of constraints, do not work as designed and do not provide
adequate protection for the subspecies. Overall, impacts from
increasing threats, operating singly or in combination, are likely to
result in the extinction of the subspecies.
Section 3 of the Endangered Species Act defines an endangered
species as ``* * * any species which is in danger of extinction
throughout all or a significant portion of its range'' and a threatened
species as ``* * * any species which is likely to become an endangered
species within the foreseeable future throughout all or a significant
portion of its range.'' Based on the immediate and ongoing significant
threats to the Miami blue butterfly throughout its entire occupied
range and the fact that the subspecies is restricted to only one or
possibly two populations, we have determined that the subspecies is in
danger of extinction throughout all of its range. Since threats extend
throughout the entire range, it is unnecessary to determine if the
Miami blue butterfly is in danger of extinction throughout a
significant portion of its range. Therefore, on the basis of the best
available scientific and commercial information, we have determined
that the Miami blue butterfly meets the definition of an endangered
species under the Act. Consequently, we are listing the Miami blue
butterfly as an endangered species throughout its entire range.
The survival of the Miami blue now depends on protecting the
species' occupied and suitable habitat from further degradation and
fragmentation, removing and reducing controllable threats, increasing
the current population in size, reducing the threats of illegal
collection, retaining the remaining genetic diversity; and establishing
populations at additional locations. The survey and monitoring efforts
and scientific studies conducted to date, when combined with other
available historical information, indicate that the Miami blue
butterfly is on the brink of extinction.
By listing the Miami blue butterfly as an endangered subspecies,
the protections (through sections 7, 9, and 10 of the Act) and
recognition that immediately became available to the subspecies upon
emergency listing will continue and increase the likelihood that it can
be saved from extinction and ultimately be recovered. In addition,
recovery funds may become available, which could facilitate recovery
actions (e.g., funding for additional surveys, management needs,
research, captive propagation and reintroduction, monitoring) (see
Available Conservation Measures, below).
The Service acknowledges that it cannot fully address some of the
natural threats facing the subspecies (e.g., hurricanes, tropical
storms) or even some of the other significant, long-term threats (e.g.,
climatic changes, sea-level rise). However, through listing, we provide
protection to the known population(s) and any new population of the
subspecies that may be discovered (see section 9 of Available
Conservation Measures, below). With listing, we can also influence
Federal actions that may potentially impact the subspecies (see section
7 below); this is especially valuable if it is found at additional
locations. With this action, we are also better able to deter illicit
collection and trade.
Through this action, the Miami blue will continue receiving
protection from collection, possession, and trade (through sections 9
and 10 of the Act). The three butterflies that are similar in
appearance to the Miami blue will receive protection from collection in
portions of their ranges (i.e., portions that overlap with the Miami
blue's historical range). At present, the three similar butterflies are
not protected by the State of Florida. Extending the prohibitions of
collection to the three similar butterflies in portions of their ranges
provides greater protection to the Miami blue. Listing will partially
alleviate some of the imminent threats that now pose a significant risk
to the survival of the subspecies.

Critical Habitat and Prudency Determination

Critical habitat is defined in section 3(5)(A) of the Act as (i)
the specific areas within the geographic area occupied by a species, at
the time it is listed in accordance with the Act, on which are found
those physical or biological features (I) essential to the conservation
of the species and (II) that may require special management
considerations or protection; and (ii) specific areas

[[Page 20981]]

outside the geographic area occupied by a species at the time it is
listed, upon a determination that such areas are essential for the
conservation of the species. Conservation is defined in section 3(3) of
the Act as the use of all methods and procedures that are necessary to
bring any endangered or threatened species to the point at which
listing under the Act is no longer necessary.
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12), require that, to the maximum extent
prudent and determinable, we designate critical habitat at the time we
determine that a species is endangered or threatened. Our regulations
(50 CFR 424.12(a)(1)) state that the designation of critical habitat is
not prudent when one or both of the following situations exist: (1) The
species is threatened by taking or other human activity, and
identification of critical habitat can be expected to increase the
degree of threat to the species, or (2) such designation of critical
habitat would not be beneficial to the species. We have determined that
both circumstances apply to the Miami blue butterfly. This
determination involves a weighing of the expected increase in threats
associated with a critical habitat designation against the benefits
gained by a critical habitat designation. An explanation of this
``balancing'' evaluation follows.

Benefits to the Subspecies From Critical Habitat Designation

The principal benefit of including an area in a critical habitat
designation is the requirement for Federal agencies to ensure actions
they fund, authorize, or carry out are not likely to result in the
destruction or adverse modification of any designated critical habitat,
the regulatory standard of section 7(a)(2) of the Act under which
consultation is completed. Federal agencies must also consult with us
on actions that may affect a listed species and refrain from
undertaking actions that are likely to jeopardize the continued
existence of such species. The analysis of effects of a proposed
project on critical habitat is separate and different from that of the
effects of a proposed project on the species itself. The jeopardy
analysis evaluates the action's impact to survival and recovery of the
species, while the destruction or adverse modification analysis
evaluates the action's effects to the designated habitat's contribution
to conservation. Therefore, the difference in outcomes of these two
analyses represents the regulatory benefit of critical habitat. This
will, in some instances, lead to different results and different
regulatory requirements. Thus, critical habitat designations may
provide greater benefits to the recovery of a species than would
listing alone.
All areas known to support the Miami blue butterfly since 1996 are
or have been on Federal or State lands; these areas are currently being
managed for the subspecies. Management efforts are consistent with, and
geared toward, Miami blue conservation, and such efforts are expected
to continue in the future. Because the butterfly exists only as one or
possibly two small metapopulations, any future activity involving a
Federal action that would destroy or adversely modify occupied critical
habitat may also likely jeopardize the subspecies' continued existence
(see Jeopardy Standard, below). Consultation with respect to critical
habitat would provide additional protection to a species only if the
agency action would result in the destruction or adverse modification
of the critical habitat but would not jeopardize the continued
existence of the species. In the absence of a critical habitat
designation, areas that support the Miami blue butterfly will continue
to be subject to conservation actions implemented under section 7(a)(1)
of the Act and to the regulatory protections afforded by the section
7(a)(2) jeopardy standard, as appropriate. Federal actions affecting
the Miami blue butterfly, even in the absence of designated critical
habitat areas, will still benefit from consultation pursuant to section
7(a)(2) of the Act and may still result in jeopardy findings.
Therefore, designation of specific areas as critical habitat that are
currently occupied or recently occupied would not likely provide a
measurable incremental benefit to the subspecies.
Another potential benefit to the Miami blue butterfly from
designating critical habitat is that it could serve to educate
landowners, State and local government agencies, Refuge or Park
visitors, and the general public regarding the potential conservation
value of the area. Through the processes of listing the butterfly under
the State of Florida's endangered species statute in 2002, the
recognition of the Miami blue as a Federal candidate subspecies in
2005, and our proposed and emergency rules for the subspecies in August
2011, much of this educational component is already in effect.
Agencies, organizations, and stakeholders are actively engaged in
efforts to raise awareness for the butterfly and its conservation
needs. For example, the NABA has a Miami blue chapter, which helps
promote awareness for the subspecies. The FWC and partners have also
formed a workgroup, in part to raise awareness for imperiled
butterflies in south Florida. Staff at BHSP have recruited volunteers
to help search for the subspecies within the Park and surrounding
areas, and they have organized speakers to inform the general public
about the butterfly. In addition, designation of critical habitat could
inform State agencies and local governments about areas that could be
conserved under State laws or local ordinances. However, since
awareness and education involving the Miami blue is already well
underway, designation of critical habitat would likely provide only
minimal incremental educational benefits.

Increased Threat to the Subspecies by Designating Critical Habitat

Designation of critical habitat requires the publication of maps
and a narrative description of specific critical habitat areas in the
Federal Register. The degree of detail in those maps and boundary
descriptions is greater than the general location descriptions provided
in this rule listing the species as endangered. At present, maps
depicting the locations of extant populations and habitat most likely
to support the Miami blue do not exist. We are concerned that
designation of critical habitat would more widely announce the exact
location of the butterflies (and highly suitable habitat) to poachers,
collectors, and vandals and further facilitate unauthorized collection
and trade. Due to its extreme rarity (a low number of individuals,
combined with small areas inhabited by the remaining metapopulation),
this butterfly is highly vulnerable to collection. Vandalism,
disturbance, and other harm from humans are also serious threats to the
butterfly and its habitat (see Factors B and E above). At this time,
removal of any individuals or damage to habitat may have devastating
consequences for the survival of the subspecies. We estimate that these
threats would be exacerbated by the publication of maps and
descriptions outlining the specific locations of this critically
imperiled butterfly in the Federal Register and local newspapers. Maps
and descriptions of critical habitat, such as those that would appear
in the Federal Register if critical habitat were designated, are not
now available to the general public.
Although we do not have specific evidence of taking for this
subspecies, illegal collection of imperiled butterflies from State,
Federal, and other lands in Florida appears ongoing, prevalent, and
damaging (see Factor B analysis above). In addition, we are aware that
a market

[[Page 20982]]

exists for trade in rare, imperiled, and listed butterflies, including
those in south Florida (see Factor B analysis above).
Additionally, we are aware of a market for butterflies that look
similar to the Miami blue, including all three of the subspecies we are
listing due to similarity of appearance (see above), as well as other
Cyclargus thomasi subspecies that occur in foreign countries. It is
clear that a demand currently exists for both imperiled butterflies and
those similar in appearance to the Miami blue. Due to its few
metapopulations, small population size, restricted range, and
remoteness of occupied habitat, we find that collection is a
significant threat to the Miami blue butterfly and could occur at any
time. Even limited collection from the remaining population (or other
populations, if discovered) could have deleterious effects on
reproductive and genetic viability and thus could contribute to its
extinction. Identification of critical habitat would increase the
severity of this threat by depicting the exact locations where the
subspecies may be found and more widely publicizing detailed
information and maps, exposing the fragile population to greater risks.
Identification and publication of critical habitat may also
increase the likelihood of inadvertent or purposeful habitat
destruction. Damage to host plants from humans has been documented in
the past (see Factor E above). Recreation within occupied areas has
resulted in trampling of vegetation and negative impacts to the
subspecies and its habitat (see Factor E above). High visitation and
illicit uses (e.g., fire pits, camping, vandalism) within occupied and
suitable habitat have resulted in local disturbances, and the risk of
fire (natural or human-induced) is now a significant threat (see Factor
E above). In addition, some private property owners in the Keys have
reportedly threatened to clear vegetation from undeveloped properties
to avoid any restrictions regarding the butterfly (M. Minno, in litt.
2011b; N. Pakhomoff-Spencer, consultant, pers. comm. 2011). We
recognize that landowner cooperation is key to the Miami blue's
survival and recovery; however, this may be reduced with critical
habitat designation. We estimate that identification and advertisement
of critical habitat may exacerbate these threats, thus making sensitive
areas more vulnerable to purposeful harmful impacts from humans.
Immature stages (eggs, larvae), which are sedentary, are particularly
vulnerable. Overall, identification and publication of detailed
critical habitat information and maps would likely increase exposure of
sensitive habitats and increase the likelihood and severity of threats
to both the subspecies and its habitat.
Identification and publication of critical habitat may lead to
increased attention to the subspecies, or increased attempts to
illegally collect it, which could also lead to an increase in
enforcement problems. Although take prohibitions exist, effective
enforcement is difficult. As discussed in Factors B, D, and E and
elsewhere above, the threat of collection and inadvertent impacts from
humans exists; areas are already difficult to patrol. Areas within the
KWNWR are remote and accessible mainly by boat, making them difficult
for law enforcement personnel to patrol and monitor. Designation of
critical habitat would facilitate further use and misuse of sensitive
habitats and resources, creating additional difficulty for law
enforcement personnel in an already challenging environment.
Overall, we find that designation of critical habitat will increase
the likelihood and severity of the threats of illegal collection of the
subspecies and destruction of sensitive habitat. With increased
attention and activities, we also anticipate that designation will
contribute to, and exacerbate enforcement issues and problems.

Increased Threat to the Subspecies Outweighs the Benefits of Critical
Habitat Designation

Upon reviewing the available information, we have determined that
the designation of critical habitat would subject the subspecies to
increased threats, while conferring little additional incremental
benefit beyond that provided by listing. With designation, minor
regulatory (e.g., consulting on adverse modifications) and educational
benefits may be realized. However, these benefits (beyond listing) will
be more than offset by the increased threats to the subspecies and its
habitat that could be associated with critical habitat designation.
Critical habitat involves the identification and publication of
detailed descriptions and maps. Publication of such maps and
information, otherwise not now available, exposes the Miami blue to an
increased threat of collection. It also increases the potential for
inadvertent or purposeful disturbance and vandalism to important and
sensitive habitats and contributes to enforcement issues. Overall, we
find that the risk of increasing significant threats to the subspecies
by publishing location information in a critical habitat designation
greatly outweighs the minimal regulatory and educational benefits of
designating critical habitat.
In conclusion, we find that the designation of critical habitat is
not prudent, in accordance with 50 CFR 424.12(a)(1), because the Miami
blue butterfly is threatened by collection and habitat destruction, and
designation can reasonably be expected to increase the degree of these
threats to the subspecies and its habitat.

Available Conservation Measures

Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness and
conservation by Federal, State, Tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and requires that recovery actions be carried out for all listed
species. The protection required by Federal agencies and the
prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
species' decline by addressing the threats to its survival and
recovery. The goal of this process is to restore listed species to a
point where they are secure, self-sustaining, and functioning
components of their ecosystems.
Recovery planning includes the development of a recovery outline
shortly after a species is listed, preparation of a draft and final
recovery plan, and revisions to the plan as significant new information
becomes available. The recovery outline guides the immediate
implementation of urgent recovery actions and describes the process to
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species,
measurable criteria that determine when a species may be downlisted or
delisted, and methods for monitoring recovery

[[Page 20983]]

progress. Recovery plans also establish a framework for agencies to
coordinate their recovery efforts and provide estimates of the cost of
implementing recovery tasks. Recovery teams (composed of species
experts, Federal and State agencies, nongovernmental organizations, and
stakeholders) are often established to develop recovery plans. When
completed, the draft recovery plan, and the final recovery plan will be
available on our Web site (http://www.fws.gov/endangered), or from our
South Florida Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a road range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. Achieving recovery of these species requires cooperative
conservation efforts on private, State, and Tribal lands.
Through this listing, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. Additionally,
under section 6 of the Act, we would be able to grant funds to the
State of Florida for management actions promoting the conservation of
the Miami blue. Information on our grant programs that are available to
aid species recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in
recovery efforts for the Miami blue. Additionally, we invite you to
submit any new information on the subspecies, its habitat, or threats
whenever it becomes available and any information you may have for
recovery planning purposes.
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as
endangered or threatened and with respect to its critical habitat, if
any is being designated. Regulations implementing this interagency
cooperation provision of the Act are codified at 50 CFR part 402.
Section 7(a)(4) requires Federal agencies to confer informally with us
on any action that is likely to jeopardize the continued existence of a
species proposed for listing or result in destruction or adverse
modification of proposed critical habitat. If a species is listed
subsequently, section 7(a)(2) of the Act requires Federal agencies to
ensure that activities they authorize, fund, or carry out are not
likely to jeopardize the continued existence of such a species or to
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with us.
Federal agency actions that may require conference or consultation
as described in the preceding paragraph include the issuance of Federal
funding, permits, or authorizations for construction, clearing,
development, road maintenance, pesticide registration, pesticide use
(on Federal land or with Federal funding), agricultural assistance
programs, Federal loan and insurance programs, Federal habitat
restoration programs, and scientific and special uses. Activities will
trigger consultation under section 7 of the Act if they may affect the
Miami blue butterfly.

Jeopardy Standard

Prior to and following listing, the Service applies an analytical
framework for jeopardy analyses that relies heavily on the importance
of core area populations to the survival and recovery of the species.
The section 7(a)(2) analysis is focused not only on these populations
but also on the habitat conditions necessary to support them.
The jeopardy analysis usually expresses the survival and recovery
needs of the species in a qualitative fashion without making
distinctions between what is necessary for survival and what is
necessary for recovery. Generally, if a proposed Federal action is
incompatible with the viability of the affected core area
populations(s), inclusive of associated habitat conditions, a jeopardy
finding is considered to be warranted, because of the relationship of
each core area population to the survival and recovery of the species
as a whole.

Section 9 Take

The Act and implementing regulations set forth a series of general
prohibitions and exceptions that apply to all endangered and threatened
wildlife. These prohibitions are applicable to the Miami blue butterfly
immediately with listing. The prohibitions of section 9(a)(2) of the
Act, codified at 50 CFR 17.21 for endangered wildlife, in part, make it
illegal for any person subject to the jurisdiction of the United States
to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect, or to attempt any of these), import or export,
deliver, receive, carry, transport, or ship in interstate or foreign
commerce in the course of commercial activity, or sell or offer for
sale in interstate or foreign commerce any listed species. It also is
illegal to possess, sell, deliver, carry, transport, or ship any such
wildlife that has been taken illegally. Further, it is illegal for any
person to attempt to commit, to solicit another person to commit, or to
cause to be committed, any of these acts. Certain exceptions apply to
our agents and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. We codified
the regulations governing permits for endangered species at 50 CFR
17.22. Such permits are available for scientific purposes, to enhance
the propagation or survival of the species, or for incidental take in
the course of otherwise lawful activities.
It is our policy, published in the Federal Register on July 1, 1994
(59 FR 34272), to identify, to the maximum extent practicable at the
time a species is listed, those activities that would or would not
constitute a violation of section 9 of the Act and associated
regulations at 50 CFR 17.21. The intent of this policy is to increase
public awareness of the effect of this final listing on proposed and
ongoing activities within a species' range. We estimate, based on the
best available information, that the following actions will not result
in a violation of the provisions of section 9 of the Act, provided
these actions are carried out in accordance with existing regulations
and permit requirements, if applicable:
(1) Possession, delivery, or movement, including interstate
transport and import into or export from the United States, involving
no commercial activity, of dead specimens of this taxon that were
collected or legally acquired prior to the effective date of the
emergency rule (August 10, 2011).
(2) Actions that may affect the Miami blue that are authorized,
funded, or carried out by Federal agencies when such activities are
conducted in accordance with an incidental take statement issued by us
under section 7 of the Act.
(3) Actions that may affect the Miami blue that are not authorized,
funded, or carried out by a Federal agency, when the action is
conducted in accordance with an incidental take permit issued by

[[Page 20984]]

us under section 10(a)(1)(B) of the Act. Applicants design a Habitat
Conservation Plan (HCP) and apply for an incidental take permit. These
HCPs are developed for species listed under section 4 of the Act and
are designed to minimize and mitigate impacts to the species to the
maximum extent practicable.
(4) Actions that may affect the Miami blue that are conducted in
accordance with the conditions of a section 10(a)(1)(A) permit for
scientific research or to enhance the propagation or survival of the
subspecies.
(5) Captive propagation activities involving the Miami blue that
are conducted in accordance with the conditions of a section
10(a)(1)(A) permit, our ``Policy Regarding Controlled Propagation of
Species Listed Under the Endangered Species Act,'' and in cooperation
with the State of Florida.
(6) Low-impact, infrequent, dispersed human activities on foot
(e.g., bird watching, butterfly watching, sightseeing, backpacking,
photography, camping, hiking) in areas occupied by the Miami blue or
where its host and nectar plants are present.
(7) Activities on private lands that do not result in take of the
Miami blue butterfly, such as normal landscape activities around a
personal residence, construction that avoids butterfly habitat, and
pesticide/herbicide application consistent with label restrictions, if
applied in areas where the subspecies is absent.
We estimate that the following activities would be likely to result
in a violation of section 9 of the Act; however, possible violations
are not limited to these actions alone:
(1) Unauthorized possession, collecting, trapping, capturing,
killing, harassing, sale, delivery, or movement, including interstate
and foreign commerce, or harming or attempting any of these actions, of
Miami blue butterflies at any life stage without a permit (research
activities where Miami blue butterflies are handled, captured (e.g.,
netted, trapped), marked, or collected will require a permit under
section 10(a)(1)(A) of the Act).
(2) Incidental take of Miami blue butterfly without a permit
pursuant to section 10 (a)(1)(B) of the Act.
(3) Sale or purchase of specimens of this taxon, except for
properly documented antique specimens of this taxon at least 100 years
old, as defined by section 10(h)(1) of the Act.
(4) Unauthorized destruction or alteration of Miami blue butterfly
habitat (including unauthorized grading, leveling, plowing, mowing,
burning, trampling, herbicide spraying, or other destruction or
modification of occupied or potentially occupied habitat or pesticide
application in known occupied habitat) in ways that kills or injures
eggs, larvae, or adult Miami blue butterflies by significantly
impairing the subspecies' essential breeding, foraging, sheltering, or
other essential life functions.
(5) Use of pesticides/herbicides that are in violation of label
restrictions resulting in take of Miami blue butterfly or beneficial
ants associated with the subspecies in areas occupied by the butterfly.
(6) Unauthorized release of biological control agents that attack
any life stage of this taxon or beneficial ants associated with the
Miami blue.
(7) Removal or destruction of native food plants being utilized by
Miami blue butterfly, including Caesalpinia spp., Cardiospermum spp.,
and Pithecellobium spp., within areas used by this taxon that results
in harm to this butterfly.
(8) Release of exotic species into occupied Miami blue butterfly
habitat that may displace the Miami blue or its native host plants.
We will review other activities not identified above on a case-by-
case basis to determine whether they may be likely to result in a
violation of section 9 of the Act. We do not consider these lists to be
exhaustive, and we provide them as information to the public.
You should direct questions regarding whether specific activities
may constitute a future violation of section 9 of the Act to the Field
Supervisor of the Service's South Florida Ecological Services Field
Office (see FOR FURTHER INFORMATION CONTACT). Requests for copies of
regulations regarding listed species and inquiries about prohibitions
and permits should be addressed to the U.S. Fish and Wildlife Service,
Ecological Services Division, Endangered Species Permits, 1875 Century
Boulevard, Atlanta, GA 30345 (Phone 404-679-7313; Fax 404-679-7081).

Similarity of Appearance

Section 4(e) of the Act authorizes the treatment of a species,
subspecies, or population segment as endangered or threatened if: ``(a)
such species so closely resembles in appearance, at the point in
question, a species which has been listed pursuant to such section that
enforcement personnel would have substantial difficulty in attempting
to differentiate between the listed and unlisted species; (b) the
effect of this substantial difficulty is an additional threat to an
endangered or threatened species; and (c) such treatment of an unlisted
species will substantially facilitate the enforcement and further the
policy of this Act.'' Listing a species as endangered or threatened
under the similarity of appearance provisions of the Act extends the
take prohibitions of section 9 of the Act to cover the species. A
designation of endangered or threatened due to similarity of appearance
under section 4(e) of the Act, however, does not extend other
protections of the Act, such as consultation requirements for Federal
agencies under section 7 and the recovery planning provisions under
section 4(f), that apply to species that are listed as endangered or
threatened under section 4(a). All applicable prohibitions and
exceptions for species listed under section 4(e) of the Act due to
similarity of appearance to a threatened or endangered species will be
set forth in a special rule under section 4(d) of the Act.
There are only slight morphological differences between the Miami
blue and the cassius blue, ceraunus blue, and nickerbean blue, making
it difficult to differentiate between the species, especially due to
their small size (see Background above). Aside from technical experts,
most people would have difficulty distinguishing these similar
butterflies (as adults, eggs, or larvae), especially without field
guides or when adults are in flight. This poses a problem for Federal
and State law enforcement agents trying to stem illegal collection and
trade in the Miami blue. It is quite possible that collectors
authorized to collect similar species may inadvertently (or
purposefully) collect the Miami blue butterfly thinking it was the
cassius blue, ceraunus blue, or nickerbean blue, which also occur in
the same geographical area and habitat type. The listing of these
similar blue butterflies as threatened due to similarity of appearance
reduces the likelihood that amateur butterfly enthusiasts and private
and commercial collectors will purposefully or accidentally
misrepresent the Miami blue as one of these other species.
The listing will also facilitate Federal and State law enforcement
agents' efforts to curtail illegal possession, collection, and trade in
the Miami blue. At this time, the three similar butterflies are not
protected by the State of Florida. Extending the prohibitions of
collection to the three similar butterflies through this listing of
these species due to similarity of appearance under section 4(e) of the
Act and providing applicable prohibitions and exceptions under section
4(d) of the Act will provide

[[Page 20985]]

greater protection to the Miami blue. For these reasons, we are listing
the cassius blue butterfly (Leptotes cassius theonus), ceraunus blue
butterfly (Hemiargus ceraunus antibubastus), and nickerbean blue
butterfly (Cyclargus ammon) as threatened due to similarity of
appearance to the Miami blue, in portions of their ranges, pursuant to
section 4(e) of the Act. Therefore, the cassius blue, ceraunus blue,
and nickerbean blue butterflies are listed as threatened species under
the Act due to similarity of appearance only within the historical
range of the Miami blue butterfly in Florida. This includes the coastal
counties south of Interstate 4 (I-4) and extending to the boundaries of
the State at the endpoints of I-4 at Tampa and Daytona Beach.
We are limiting the listing of these similar butterflies to only a
portion of their ranges because we find this is sufficient to protect
the Miami blue (from collection) while being responsive to comments
received (see Comments Relating to Similarity of Appearance
Butterflies, especially Comment 17 and Response above).

Special Rule Under Section 4(d) of the Act

Whenever a species is listed as a threatened species under the Act,
the Secretary may specify regulations that he deems necessary and
advisable to provide for the conservation of that species under the
authorization of section 4(d) of the Act. These rules, commonly
referred to as ``special rules,'' are found in part 17 of title 50 of
the Code of Federal Regulations (CFR) in Sec. Sec. 17.40-17.48. This
special rule for Sec. 17.47 prohibits take of any cassius blue
butterfly (Leptotes cassius theonus), ceraunus blue butterfly
(Hemiargus ceraunus antibubastus), or nickerbean blue butterfly
(Cyclargus ammon) or their immature stages only throughout coastal
south and central Florida in order to protect the Miami blue butterfly
from collection, possession, and trade. In this context, any activity
where cassius blue, ceraunus blue, or nickerbean blue butterflies or
their immature stages are attempted to be, or are intended to be,
collected, in counties that overlap with the Miami blue's historical
range in Florida, are prohibited. Collection of the similar butterflies
is prohibited south of I-4 and extending to the boundaries of the State
of Florida at the endpoints of I-4 at Tampa and Daytona Beach.
Specifically, such activities are prohibited in the following counties:
Brevard, Broward, Charlotte, Collier, De Soto, Hillsborough, Indian
River, Lee, Manatee, Pinellas, Sarasota, St. Lucie, Martin, Miami-Dade,
Monroe, Palm Beach, and Volusia.
Capture of cassius blue, ceraunus blue, or nickerbean blue
butterflies, or their immature stages, is not prohibited if it is
accidental or incidental to otherwise legal collection activities, such
as research, provided the animal is released immediately upon discovery
at the point of capture. Scientific activities involving collection or
propagation of these similarity of appearance butterflies are not
prohibited, provided there is prior written authorization from the
Service. All otherwise legal activities involving cassius blue,
ceraunus blue, or nickerbean blue butterflies that are conducted in
accordance with applicable State, Federal, Tribal, and local laws and
regulations are not considered to be take under this regulation. For
further explanation see ``Effects of the Rule'' immediately below.

Effects of the Rule

Listing the cassius blue, ceraunus blue, and nickerbean blue
butterflies as threatened under the ``similarity of appearance''
provisions of the Act, and the promulgation of a special rule under
section 4(d) of the Act, extend take prohibitions to these species and
their immature stages in portions of their ranges. Capture of these
species, including their immature stages, is not prohibited if it is
accidental or incidental to otherwise legal collection activities, such
as research, provided the animal is released immediately upon
discovery, at the point of capture. However, this final rule
establishes prohibitions on the collection of these species throughout
coastal south and central Florida within the historical range of the
Miami blue butterfly.
All otherwise legal activities that may involve incidental take
(take that results from, but is not the purpose of, carrying out an
otherwise lawful activity) of these similar butterflies, and which are
conducted in accordance with applicable State, Federal, Tribal, and
local laws and regulations, will not be considered take under this
regulation. For example, this special 4(d) rule exempts legal
application of pesticides, yard care, vehicle use, vegetation
management, exotic plant removal, burning, and any other legally
undertaken actions that result in the accidental take of cassius blue,
ceraunus blue, or nickerbean blue butterflies. These actions will not
be considered as violations of section 9 of the Act. We find that
listing the cassius blue, ceraunus blue, and nickerbean blue
butterflies under the similarity of appearance provision of the Act,
coupled with this special 4(d) rule, will help minimize enforcement
problems and enhance conservation of the Miami blue.
The provision to allow incidental take of these three similar
butterflies will not pose a threat to the Miami blue because: (1)
Activities such as yard care and vegetation control in developed or
commercial areas that are likely to result in take of the cassius blue,
ceraunus blue, and nickerbean blue are not likely to affect the Miami
blue (which occur only on conservation lands), and (2) the primary
threat that activities concerning the cassius blue, ceraunus blue, and
nickerbean blue butterflies pose to the Miami blue comes from
collection.

Administrative Procedure Act

As explained previously in Previous Federal Actions above, we
believe that it is necessary to establish immediate protections under
the Act for these butterfly species. The August 10, 2011, emergency
rule (76 FR 49542) that implemented protections for 240 days expires
April 6, 2012. Therefore, under the exemption provided in the
Administrative Procedure Act (5 U.S.C. 553(d)(3)), we have determined
that ``good cause'' exists to make these regulations effective as
stated above (see DATES).

Required Determinations

Clarity of Rule

We are required by Executive Orders 12866 and 12988 and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must: (a) Be logically
organized; (b) Use the active voice to address readers directly; (c)
Use clear language rather than jargon; (d) Be divided into short
sections and sentences; and (e) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in the ADDRESSES section. To
better help us revise the rule, your comments should be as specific as
possible. For example, you should tell us page numbers and the names of
the sections or paragraphs that are unclearly written, which sections
or sentences are too long, the sections where you feel lists or tables
would be useful, etc.

Paperwork Reduction Act (44 U.S.C. 3501, et seq.)

This final rule does not contain any new collections of information
that require approval by the Office of Management and Budget (OMB)
under the Paperwork Reduction Act. This rule will not impose new
recordkeeping or

[[Page 20986]]

reporting requirements on State or local governments, individuals,
businesses, or organizations. We may not conduct or sponsor, and you
are not required to respond to, a collection of information unless it
displays a currently valid OMB control number.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

We have determined that we do not need to prepare an environmental
assessment, as defined under the authority of the National
Environmental Policy Act of 1969, in connection with regulations
adopted under section 4(a) of the Act. We published a notice outlining
our reasons for this determination in the Federal Register on October
25, 1983 (48 FR 49244).

References Cited

A complete list of all references cited in this final rule is
available on the Internet at http://www.regulations.gov or upon request
from the Field Supervisor, South Florida Ecological Services Office
(see FOR FURTHER INFORMATION CONTACT).

Authors

The primary authors of this rule are staff members of the South
Florida Ecological Services Office (see FOR FURTHER INFORMATION
CONTACT).

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.

Regulation Promulgation

Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as follows:

PART 17--[AMENDED]

0
1. The authority citation for part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

0
2. Amend Sec. 17.11(h) by adding new entries for the following, in
alphabetical order under Insects, to the List of Endangered and
Threatened Wildlife:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *
(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------------- population
Historic range where Status When listed Critical
Common name Scientific name endangered or habitat
threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *
Insects

* * * * * * *
Butterfly, cassius blue............. Leptotes cassius U.S.A. (FL), Bahamas, NA T (S/A) (coastal south 801 NA
theonus. Greater Antilles, and central FL).
Cayman Islands.
Butterfly, ceraunus blue............ Hemiargus ceraunus U.S.A. (FL), Bahamas... NA T (S/A) (coastal south 801 NA
antibubastus. and central FL).

* * * * * * *
Butterfly, Miami blue............... Cyclargus thomasi U.S.A. (FL), Bahamas... NA E..................... 801 NA
bethunebakeri.

* * * * * * *
Butterfly, nickerbean blue.......... Cyclargus ammon........ U.S.A. (FL), Bahamas, NA T (S/A) (coastal south 801 NA
Cuba. and central FL).

* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
3. In subpart D, add Sec. 17.47 to read as follows:

Sec. 17.47 Special rules--insects.

(a) Cassius blue butterfly (Leptotes cassius theonus), Ceraunus
blue butterfly (Hemiargus ceraunus antibubastus), and Nickerbean blue
butterfly (Cyclargus ammon).
(1) The provisions of Sec. 17.31(c) apply to these species
(cassius blue butterfly, ceraunus blue butterfly, nickerbean blue
butterfly), regardless of whether in the wild or in captivity, and also
apply to the progeny of any such butterfly.
(2) Any violation of State law will also be a violation of the Act.
(3) Incidental take, that is, take that results from, but is not
the purpose of, carrying out an otherwise lawful activity, will not
apply to the cassius blue butterfly, ceraunus blue butterfly, and
nickerbean blue butterfly.
(4) Collection of the cassius blue butterfly, ceraunus blue
butterfly, and nickerbean blue butterfly is prohibited in coastal
counties south of Interstate 4 and extending to the boundaries of the
State of Florida at the endpoints of Interstate 4 at Tampa and Daytona
Beach. Specifically, such activities are prohibited in the following
counties: Brevard, Broward, Charlotte, Collier, De Soto, Hillsborough,
Indian River, Lee, Manatee, Pinellas, Sarasota, St. Lucie, Martin,
Miami-Dade, Monroe, Palm Beach, and Volusia.
(b) [Reserved].

Dated: March 27, 2012.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-8088 Filed 4-5-12; 8:45 am]
BILLING CODE 4310-55-P