[Federal Register Volume 81, Number 182 (Tuesday, September 20, 2016)]
[Proposed Rules]
[Pages 64414-64426]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-22592]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R1-ES-2016-0057; 4500030113]
RIN 1018-BB54
Endangered and Threatened Wildlife and Plants; Threatened Species
Status for the Iiwi (Drepanis coccinea)
AGENCY: Fish and Wildlife Service, Interior.
ACTION: 12-Month petition finding; proposed rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the iiwi (Drepanis coccinea), a
bird species from the Hawaiian Islands, as a threatened species under
the Endangered Species Act (Act). After review of all best available
scientific and commercial information, we find that listing the iiwi as
a threatened species under the Act is warranted. Accordingly, we
propose to list the iiwi as a threatened species throughout its range.
If we finalize this rule as proposed, it would extend the Act's
protections to this species. The effect of this regulation will be to
add this species to the Federal List of Endangered and Threatened
Wildlife.
DATES: We will accept comments received or postmarked on or before
November 21, 2016. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES below) must be received by 11:59 p.m.
Eastern Time on the closing date. We must receive requests for public
hearings, in writing, at the address shown in FOR FURTHER INFORMATION
CONTACT by November 4, 2016.
ADDRESSES: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter FWS-R1-ES-2016-0057,
which is the docket number for this rulemaking. Then, in the Search
panel on the left side of the screen, under the Document Type heading,
click on the Proposed Rules link to locate this document. You may
submit a comment by clicking on ``Comment Now!''
(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public
Comments Processing, Attn: FWS-R1-ES-2016-0057; U.S. Fish and Wildlife
Service Headquarters, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA
22041-3803.
We request that you send comments only by the methods described
above. We will post all comments on http://www.regulations.gov. This
generally means that we will post any personal information you provide
us (see Public Comments below for more information).
FOR FURTHER INFORMATION CONTACT: Mary Abrams, Field Supervisor, Pacific
Islands Fish and Wildlife Office, 300 Ala Moana Boulevard, Room 3-122,
Honolulu, HI 96850; by telephone (808-792-9400); or by facsimile (808-
792-9581). Persons who use a telecommunications device for the deaf
(TDD) may call the Federal Information Relay Service (FIRS) at 800-877-
8339.
SUPPLEMENTARY INFORMATION: This document consists of: (1) A 12-month
petition finding that listing the iiwi under the Act is warranted; and
(2) a proposed rule to list the iiwi as a threatened species under the
Act.
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act, 16
U.S.C. 1531 et seq., a species or subspecies may warrant protection
through listing if it is endangered or threatened throughout all or a
significant portion of its range. Critical habitat shall be designated,
to the maximum extent prudent and determinable, for any species
determined to be an endangered or threatened species under the Act.
We are proposing to list the iiwi (Drepanis coccinea) as threatened
under the Act because of current and future threats, and listing can
only be done by issuing a rule. The iiwi no longer occurs across much
of its historical range, and faces a variety of threats in the form of
diseases and impacts to its remaining habitat.
Delineation of critical habitat requires, within the geographical
area occupied by the species, identification of the physical or
biological features essential to the species' conservation. A careful
assessment of the biological needs of the species and the areas that
may have the physical or biological features essential for the
conservation of the species and that may require special management
considerations or protections, and thus qualify for designation as
critical habitat, is particularly complicated in this case by the
ongoing and projected effects of climate change and will require a
thorough assessment. We require additional time to analyze the best
available scientific data in order to identify specific areas
appropriate for critical habitat designation and to analyze the impacts
of designating such areas as critical habitat. Accordingly, we find
designation of critical habitat for the iiwi to be ``not determinable''
at this time.
What this document does. This document proposes the listing of the
iiwi as a threatened species. We previously published a 90-day finding
for the iiwi, and this document includes a 12-month finding and
proposed listing rule, which assesses all available information
regarding status of and threats to the iiwi.
The basis for our action. Under the Act, we can determine that a
species is an endangered or threatened species based on any of 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. We have determined that the primary threats to the
iiwi are its susceptibility to avian malaria (Factor C) and the
expected reduction in disease-free habitat as a result of increased
temperatures caused by climate change (Factor E). Although not
identified as primary threat factors, rapid ohia death, a disease that
affects the tree species required by iiwi for nesting and foraging, and
impacts from nonnative invasive plants and feral ungulates, contribute
to the degradation and curtailment of the iiwi's remaining, disease-
free native ohia forest habitat, exacerbating threats to the species'
viability.
We will seek peer review. We will seek comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses. We will invite these peer
reviewers to comment on our listing proposal. Because we will consider
all comments and information received during the comment period, our
final determination may differ from this proposal.
A species status report for the iiwi was prepared by a team of
Service biologists, with the assistance of scientists from the U.S.
Geological Survey's (USGS) Pacific Islands Ecosystems Research Center
and the Service's Pacific Islands Climate Change
[[Page 64415]]
Cooperative. We also obtained review and input from experts familiar
with avian malaria and avian genetics. The species status report
represents a compilation of the best scientific and commercial data
available concerning the status of the species, including the past,
present, and future threats to the iiwi. We will invite at least three
scientists with expertise in Hawaiian forest bird biology, avian
malaria, and climate change to conduct an independent peer review of
the species status report. The species status report and other
materials relating to this proposal can be found at http://www.regulations.gov, at Docket No. FWS-R1-ES-2016-0057, or by
contacting the Pacific Islands Fish and Wildlife Office (see FOR
FURTHER INFORMATION CONTACT).
Information Requested
Public Comments
We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and as effective as possible. Therefore, we request
comments or information from the public, including land owners and land
managers, other concerned governmental agencies, the scientific
community, industry, or any other interested parties concerning this
proposed rule. We particularly seek comments concerning:
(1) The iiwi's biology, range, and population trends, including:
(a) Biological or ecological requirements of the species, including
habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for the species, its
habitat, or both.
(2) Factors that may affect the continued existence of the species,
which may include habitat modification or destruction, overutilization,
disease, predation, the inadequacy of existing regulatory mechanisms,
or other natural or manmade factors.
(3) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to this species and existing regulations
that may be addressing those threats.
(4) Additional information concerning the historical and current
status, range, distribution, and population size of this species,
including the locations of any additional populations of the iiwi.
(5) Specific information on:
What areas currently occupied, and that contain the
necessary physical or biological features essential for the
conservation of the iiwi, we should include in any future designation
of critical habitat and why;
Whether special management considerations or protections
may be required for the physical or biological features essential to
the conservation of the iiwi; and
What areas not currently occupied are essential to the
conservation of the iiwi and why.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Please note that submissions merely stating support for or
opposition to the action under consideration without providing
supporting information, although noted, will not be considered in
making a determination, as section 4(b)(1)(A) of the Act directs that
determinations as to whether any species is a threatened or endangered
species must be made ``solely on the basis of the best scientific and
commercial data available.''
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in ADDRESSES. We request that you
send comments only by the methods described in ADDRESSES.
If you submit information via http://www.regulations.gov, your
entire submission--including any personal identifying information--will
be posted on the Web site. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this information from public
review. However, we cannot guarantee that we will be able to do so. We
will post all hardcopy submissions on http://www.regulations.gov.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on http://www.regulations.gov, or by
appointment, during normal business hours, at the U.S. Fish and
Wildlife Service, Pacific Islands Fish and Wildlife Office (see FOR
FURTHER INFORMATION CONTACT).
Public Hearing
Section 4(b)(5) of the Act provides for one or more public hearings
on this proposal, if requested. Requests must be received within 45
days after the date of publication of this proposed rule in the Federal
Register. Such requests must be sent to the address shown in FOR
FURTHER INFORMATION CONTACT. We will schedule one or more public
hearings on this proposal, if any are requested, and announce the
dates, times, and places of those hearings, as well as how to obtain
reasonable accommodations, in the Federal Register and local newspapers
at least 15 days before the hearing.
Peer Review
In accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), we will seek the expert
opinions of appropriate and independent specialists regarding this
proposed rule and the accompanying draft species status report (see
Status Assessment for the Iiwi, below). The purpose of peer review is
to ensure that our listing determination is based on scientifically
sound data, assumptions, and analyses. Peer reviewers have expertise in
the iiwi's life history, habitat, physical and biological requirements,
avian diseases including malaria, and climate change, and are currently
reviewing the draft species status report, which will inform our
determination. We invite comment from the peer reviewers during this
public comment period.
Background
Section 4(b)(3)(B) of the Act requires that, for any petition to
revise the Federal Lists of Threatened and Endangered Wildlife and
Plants (Lists) that contains substantial scientific or commercial
information indicating that listing a species may be warranted, we make
a finding within 12 months of the date of receipt of the petition that
the petitioned action is either: (a) Not warranted; (b) warranted; or
(3) warranted, but the immediate proposal of a regulation implementing
the petitioned action is precluded by pending proposals to determine
whether other species are endangered or threatened, and expeditious
progress is being made to add or remove qualified species from the
Lists. With this publication, we have determined that the petitioned
action to list the iiwi is warranted, and we are proposing to list the
species.
Previous Federal Actions
On August 25, 2010, we received a petition dated August 24, 2010,
from Noah Greenwald, Center for Biological Diversity, and Dr. Tony
Povilitis, Life Net, requesting that the iiwi be listed as an
endangered or threatened species and that critical habitat be
designated under the Act. In a September 10, 2010, letter to the
petitioners, we responded
[[Page 64416]]
that we had reviewed the information presented in the petition and
determined that issuing an emergency regulation temporarily listing the
species under section 4(b)(7) of the Act was not warranted. We also
stated that we were required to complete a significant number of
listing and critical habitat actions in Fiscal Year 2010, including
complying with court orders and court-approved settlement agreements
with specific deadlines, listing actions with absolute statutory
deadlines, and high-priority listing actions. Our listing and critical
habitat funding for Fiscal Year 2010 was committed to complying with
these court orders, settlement agreements, and statutory deadlines.
Therefore, we were unable to further address the petition to list the
iiwi at that time.
We published a 90-day finding for the iiwi in the Federal Register
on January 24, 2012 (77 FR 3423). Based on that review, we found that
the petition presented substantial information indicating that listing
the iiwi may be warranted, and we initiated a status review of the
species. With the publication of this notice, we provide our 12-month
finding and a proposal to list the iiwi as a threatened species under
the Act.
Status Assessment for the Iiwi
A thorough review of the taxonomy, life history, and ecology of the
iiwi (Drepanis coccinea) is presented in the draft Iiwi (Drepanis
coccinea) Species Status Report, available online at http://www.regulations.gov under Docket No. FWS-R1-ES-2016-0057. The species
status report documents the results of our comprehensive biological
status review for the iiwi, including an assessment of the potential
stressors to the species. The species status report does not represent
a decision by the Service on whether the iiwi should be proposed for
listing as a threatened or endangered species under the Act. It does,
however, provide the scientific basis that informs our regulatory
decision, which involves the further application of standards within
the Act and its implementing regulations and policies. The following is
a summary of the key results and conclusions from the species status
report.
Summary of Biological Status
A medium-sized forest bird notable for its iconic bright red
feathers, black wings and tail, and a long, curved bill (Hawaii Audubon
Society 2011, p. 97), the iiwi belongs to the family Fringillidae and
the endemic Hawaiian honeycreeper subfamily, Drepanidinae (Pratt et al.
2009, pp. 114, 122). Iiwi songs are complex with variable creaks (often
described as sounding like a ``rusty hinge''), whistles, or gurgling
sounds, and they sometimes mimic other birds (Hawaii Audubon Society
2011, p. 97). The species is found primarily in closed canopy, montane
wet or montane mesic forests composed of tall stature ohia
(Metrosideros polymorpha) trees or ohia and koa (Acacia koa) tree mixed
forest. The iiwi's diet consists primarily of nectar from the flowers
of ohia and mamane (Sophora chrysophylla), various plants in the
lobelia (Campanulaceae) family (Pratt et al. 2009, p. 193), and
occasionally, insects and spiders (Pratt et al. 2009, p. 193; Hawaii
Audubon Society 2011, p. 97).
Although iiwi may breed anytime between October and August (Hawaii
Audubon Society 2011, p. 97), the main breeding season occurs between
February and June, which coincides with peak flowering of ohia (Fancy
and Ralph 1997, p. 2). Iiwi create cup-shaped nests typically within
the upper canopy of ohia (Hawaii Audubon Society 2011, p. 97), and
breeding pairs defend a small area around the nest and disperse after
the breeding season (Fancy and Ralph 1997, p. 2). An iiwi clutch
typically consists of two eggs, with a breeding pair raising one to two
broods per year (Hawaii Audubon Society 2011, p. 97).
Well known for their seasonal movements in response to the
availability of flowering ohia and mamane, iiwi are strong fliers that
move long distances following their breeding season to locate nectar
sources (Fancy and Ralph 1998, p. 3; Kuntz 2008, p. 1; Guillamet et al.
2015, pp. EV-8--EV-9). The iiwi's seasonal movement to lower elevation
areas in search of nectar sources is an important factor in the
exposure of the species to avian diseases, particularly malaria
(discussed below).
Although historical abundance estimates are not available, the iiwi
was considered one of the most common of the native forest birds in
Hawaii by early naturalists, described as ``ubiquitous'' and found from
sea level to the tree line across all the major islands (Banko 1981,
pp. 1-2). Today the iiwi is no longer found on Lanai and only a few
individuals may be found on Oahu, Molokai, and west Maui. Remaining
populations of iiwi are largely restricted to forests above
approximately 3,937 feet (ft) (1,200 meters (m)) in elevation on Hawaii
Island (Big Island), east Maui, and Kauai. As described below, the
present distribution of iiwi corresponds with areas that are above the
elevation at which the transmission of avian malaria readily occurs
(``disease-free'' habitats). The current abundance of iiwi rangewide is
estimated at a mean of 605,418 individuals (range 550,972 to 659,864).
Ninety percent of all iiwi now occur on Hawaii Island, followed by east
Maui (about 10 percent), and Kauai (less than 1 percent) (Paxton et al.
2013, p. 10).
Iiwi population trends and abundance vary across the islands. The
population on Kauai appears to be in steep decline, with a modeled rate
of decrease equivalent to a 92 percent reduction in population over a
25-year period (Paxton et al. 2013, p. 10); the total population on
Kauai is estimated at a mean of 2,551 birds (range 1,934 to 3,167)
(Paxton et al. 2013, p. 10). Trends on Maui are mixed, but populations
there generally appear to be in decline; East Maui supports an
estimated population of 59,859 individuals (range 54,569 to 65,148)
(Paxton et al. 2013, p. 10). On Hawaii Island, which supports the
largest remaining numbers of iiwi at an estimated average of 543,009
individuals (range 516,312 to 569,706), there is evidence for stable or
declining populations on the windward side of the island, while trends
are strongly increasing on the leeward (Kona) side. As noted above,
iiwi have been extirpated from Lanai, and only a few individual birds
have been sporadically detected on the islands of Oahu, Molokai, and on
west Maui in recent decades. Of the nine iiwi population regions for
which sufficient information is available for quantitative inference,
five of those show strong or very strong evidence of declining
populations; one, a stable to declining population; one, a stable to
increasing population; and two, strong evidence for increasing
populations. Four of the nine regions show evidence of range
contraction. Overall, based on the most recent surveys (up to 2012),
approximately 90 percent of remaining iiwi are restricted to forest
within a narrow band between 4,265 and 6,234 ft (1,300 and 1,900 m) in
elevation (Paxton et al. 2013, pp. 1, 10-11, and Figure 1) (See the
Population Status section of the draft species status report for
details).
Summary of Factors Affecting the Species
The Act directs us to determine whether any species is an
endangered species or a threatened species because of any of five
various factors affecting its continued existence. Our species status
report evaluated many potential stressors to iiwi, particularly direct
impacts on the species from introduced diseases, as well as predation
by
[[Page 64417]]
introduced mammals, competition with nonnative birds, climate change,
ectoparasites, and the effects of small population size. We also
assessed stressors that may affect the extent or quality of the iiwi's
required ohia forest habitat, including ohia dieback, ohia rust,
drought, fires, volcanic eruptions, climate change, and particularly
rapid ohia death and habitat alteration by nonnative plants and feral
ungulates.
All species experience stressors; we consider a stressor to rise to
the level of a threat to the species if the magnitude of the stressor
is such that it places the current or future viability of the species
at risk. In considering what stressors or factors might constitute
threats to a species, we must look beyond the exposure of the species
to a particular stressor to evaluate whether the species may respond to
that stressor in a way that causes impacts to the species now or is
likely to cause impacts in the future. If there is exposure to a
stressor and the species responds negatively, the stressor may be a
threat. We consider the stressor to be a threat if it drives, or
contributes to, the risk of extinction of the species such that the
species warrants listing as endangered or threatened as those terms are
defined in the Act. However, the identification of stressors that could
affect a species negatively may not be sufficient to compel a finding
that the species warrants listing. The information must include
evidence sufficient to suggest that these stressors are operative
threats that act on the species to the point that the species may meet
the definition of endangered or threatened under the Act.
Our species status report examines all of the potential stressors
to iiwi in detail. Here we describe those stressors that we conclude
rise to the level of a threat to the long-term viability of iiwi.
Based on our comprehensive assessment of the status of the iiwi in
our species status report, we conclude that the best scientific data
available consistently identifies avian malaria as the primary driver
of declines in abundance and distribution of iiwi observed since the
turn of the 20th century. This conclusion is supported by the extremely
high mortality rate of iiwi (approximately 95 percent) in response to
avian malaria, and the disappearance of iiwi from low-elevation ohia
forest where it was formerly common and where malaria is prevalent
today. Both the life cycle of the mosquito vector and the development
and transmission of the malaria parasite are temperature-limited, thus
iiwi are now found primarily in high elevation forests above 3,937 ft
(1,200 m) where malaria prevalence and transmission is only brief and
episodic, or nonexistent, under current conditions. Iiwi have not
demonstrated any substantial sign of developing resistance to avian
malaria to date and do not appear to be genetically predisposed to
evolve resistance (Jarvi et al. 2004, pp. 2,164-2,166). As the
prevalence of avian malaria increases in association with warmer
temperatures (e.g., LaPointe et al. 2012, p. 217), the extent and
impact of avian diseases upon iiwi are projected to become greatly
exacerbated by climate change during this century.
Additionally, on Hawaii Island where 90 percent of the iiwi
currently occur, the disease rapid ohia death was identified as an
emergent source of habitat loss and degradation that has the potential
to exacerbate other stressors to ohia forest habitat, as well as reduce
the amount of habitat remaining for iiwi in an already limited,
disease-free zone contained within a narrow elevation band. Rapid ohia
death, a recently discovered tree disease that leads to significant
mortality of the ohia that iiwi depend upon for nesting and foraging,
is quickly becoming a matter of urgent concern. If rapid ohia death
continues to spread across the native ohia forests, it will directly
threaten iiwi by eliminating the limited, malaria-free native forest
areas that remain for the species.
Based on the analysis in our species status report, invasive,
nonnative plants and feral ungulates have major, adverse impacts on
ohia forest habitat. Although we did not find that the historical and
ongoing habitat alteration by nonnative species is the primary cause of
the significant observed decline in iiwi's abundance and distribution,
the cumulative impacts to iiwi's habitat, and in particular the
activities of feral ungulates, are not insignificant and likely
exacerbate the effects of avian malaria. Feral ungulates, particularly
pigs (Sus scrofa), goats (Capra hircus), and axis deer (Axis axis),
degrade ohia forest habitat by spreading nonnative plant seeds and
grazing on and trampling native vegetation, and contributing to erosion
(Mountainspring 1986, p. 95; Camp et al. 2010, p. 198). Invasive
nonnative plants, such as strawberry guava (Psidium cattleianum) and
albizia trees (Falcataria moluccana), prevent or retard regeneration of
ohia forest used by iiwi for foraging and nesting. The combined effects
of drought and nonnative, invasive grasses have resulted in increased
fire frequency and the conversion of mesic ohia woodland to exotic
grassland in many areas of Hawaii ((D'Antonio and Vitousek 1992, p. 67;
Smith and Tunison 1992, pp. 395-397; Vitousek et al. 1997, pp. 7-8;
D'Antonio et al. 2011, p. 1,617). Beyond alteration of ohia forest,
feral pig activities that create mosquito habitat in ohia forest where
there would otherwise be very little to none is identified as an
important compounding stressor that acts synergistically with the
prevalence of malaria and results in iiwi mortality. Although habitat
loss and degradation is not, by itself, considered to be a primary
driver of iiwi declines, the habitat impacts described above contribute
cumulatively to the vulnerability of the species to the threat of avian
malaria by degrading the quality and quantity of the remaining disease-
free habitat upon which the iiwi depends. In this regard, rapid ohia
death, discussed above, is quickly becoming a matter of urgent concern
as it can further exacerbate and compound effects from the suite of
stressors that impact iiwi (see below).
Avian Diseases
The introduction of avian diseases transmitted by the introduced
southern house mosquito (Culex quinquefasciatus), including avian
malaria (caused by the protozoan Plasmodium relictum) and avian pox
(Avipoxvirus sp.), has been a key driving force in both extinctions and
extensive declines over the last century in the abundance, diversity,
and distribution of many Hawaiian forest bird species, including
declines of the iiwi and other endemic honeycreepers (e.g., Warner
1968, entire; Van Riper et al. 1986, entire; Benning et al. 2002, p.
14,246; Atkinson and LaPointe 2009a, p. 243; Atkinson and LaPointe
2009b, pp. 55-56; Samuel et al. 2011, p. 2,970; LaPointe et al. 2012,
p. 214; Samuel et al. 2015, pp. 13-15). Nonnative to Hawaii, the first
species of mosquitoes were accidentally introduced to the Hawaiian
Islands in 1826, and spread quickly to the lowlands of all the major
islands (Warner 1968, p. 104; Van Riper et al. 1986, p. 340). Early
observations of birds with characteristic lesions suggest that avian
poxvirus was established in Hawaii by the late 1800s (Warner 1968, p.
106; Atkinson and LaPointe 2009a, p. 55), and later genetic analyses
indicate pox was present in the Hawaiian Islands by at least 1900
(Jarvi et al. 2008, p. 339). Avian malaria had arrived in Hawaii by at
least 1920 (Warner 1968, p. 107; Van Riper et al. 1986, pp. 340-341;
Atkinson and LaPointe 2009, p. 55; Banko and Banko 2009, p. 52), likely
in association with imported cage birds (Yorinks and Atkinson 2000, p.
731), or through the deliberate introduction of nonnative birds to
replace the native birds that had
[[Page 64418]]
by then disappeared from the lowlands (Atkinson and LaPointe 2009a, p.
55).
Avian Malaria
As noted above, avian malaria is a disease caused by the protozoan
parasite Plasmodium relictum; the parasite is transmitted by the
mosquito Culex quinquefasciatus, and invades the red blood cells of
birds. Birds suffering from malaria infection undergo an acute phase of
the disease during which parasitemia, a quantitative measure of the
number of Plasmodium parasites in the circulating red blood cells,
increases steadily. Because the parasite destroys the red blood cells,
anemia and decline of physical condition can quickly result. In native
Hawaiian forest birds, death may result either directly from the
effects of anemia, or indirectly when anemia-weakened birds become
vulnerable to predation, starvation, or a combination of other
stressors (LaPointe et al. 2012, p. 213). Studies have demonstrated
that native Hawaiian birds that survive avian malaria remain
chronically infected, thus becoming lifetime reservoirs of the disease
(Samuel et al. 2011, p. 2,960; LaPointe et al. 2012, p. 216) and
remaining capable of further disease transmission to other native
birds. In contrast, nonnative birds in Hawaii are little affected by
avian malaria and later become incapable of disease transmission
(LaPointe et al. 2012, p. 216).
Wild iiwi infected with malaria are rarely captured, apparently
because the onset of infection leads to rapid mortality, precluding
their capture (Samuel et al. 2011, p. 2,967; LaPointe et al. 2016, p.
11). However, controlled experiments with captive birds have
demonstrated the susceptibility of native Hawaiian honeycreepers to
avian malaria; mortality is extremely high in some species, including
iiwi, experimentally infected with the disease. As early as the 1960s,
experiments with Laysan finches (Telespiza cantans) and several other
species of native Hawaiian honeycreepers demonstrated 100 percent
mortality from malaria in a very short period of time (Warner 1968, pp.
109-112, 118; Fig. 426). In a study specific to iiwi, Atkinson et al.
(1995, entire) demonstrated that the species suffers approximately 95
percent mortality when infected with malaria (Atkinson et al. 1995, p.
S65). In that study, iiwi and a nonnative control species were exposed
to avian malaria through infective mosquito bites, and subjected to
different dosages of infection (single vs. multiple bites). Following
exposure to biting mosquitoes, food consumption, weight, and
parasitemia were monitored for all test groups. None of the nonnative
birds developed malarial infections, while all of the exposed iiwi
developed infections within 4 days. Mortality of the high-dose iiwi
reached 100 percent by day 29, and mortality of the low-dose birds
reached 90 percent by day 37, an average of 95 percent mortality
between the two groups (Atkinson et al. 1994, p. S63). A single male
iiwi survived the initial infection and, following re-exposure with the
same Plasmodium isolate, no subsequent increase in parasitemia was
detected, suggesting a possible development of some immunity (Atkinson
et al. 1995, p. S66). The authors suggested that iiwi may lack
sufficient diversity in the major histocompatibility complex or
genetically based immunity traits capable of recognizing and responding
to malarial antigens, an important factor in iiwi's susceptibility to
introduced disease (Atkinson et al. 1995, pp. S65-S66).
Despite extremely high mortality of iiwi from avian malaria in
general, the aforementioned study as well as two other studies have
demonstrated that a few individuals are capable of surviving the
infection (Van Riper et al. 1986, p. 334; Atkinson et al. 1995, p. S63;
Freed et al. 2005, p. 759). If a genetic correlation were identified,
it is possible that surviving individuals could serve as a potential
source for the evolution of genetic resistance to malaria, although
evidence of this is scant to date. Eggert et al. (2008, p. 8) reported
a slight but detectable level of genetic differentiation between iiwi
populations located at mid and high elevation, potentially the first
sign of selection acting on these populations in response to disease.
Additionally, the infrequent but occasional sighting of iiwi on Oahu
indicates a possible developed resistance or tolerance to avian
malaria.
Despite these observations, there is, as of yet, no indication that
iiwi have developed significant resistance to malaria such that
individuals can survive in areas where the disease is strongly
prevalent, including all potential low-elevation forest habitat and
most mid-elevation forest habitat (Foster et al. 2007, p. 4,743; Eggert
et al. 2008, p. 2). In one study, for example, 4 years of mist-netting
effort across extensive areas of Hawaii Island resulted in the capture
of a substantial number of iiwi, yet no iiwi were captured in low-
elevation forests and only a few were captured in mid-elevation forests
(Samuel et al. 2015, p. 11). In addition, the results of several
studies indicate that iiwi have low genetic variability, and even
genetic impediments to a possible evolved resistance to malaria in the
future (Jarvi et al. 2001, p. 255; Jarvi et al. 2004, Table 4, p.
2,164; Foster et al. 2007, p. 4,744; Samuel et al. 2015, pp. 12-13).
For example, Eggert et al. (2008, p. 9) noted that gene variations that
may confer resistance appear to be rare in iiwi. Three factors--the
homogeneity of a portion of the iiwi genome, the high mortality rate of
iiwi in response to avian malaria, and high levels of gene flow
resulting from the wide-ranging nature of the species--suggest that
iiwi would likely require a significant amount of time for development
of genetic resistance to avian malaria, assuming the species retains a
sufficiently large reservoir of genetic diversity for a response to
natural selection. Genetic studies of iiwi have also noted a dichotomy
between the lack of variation in mitochondrial DNA (Tarr and Fleischer
1993, 1995; Fleischer et al. 1998; Foster et al. 2007, p. 4,743), and
maintenance of variation in nuclear DNA (Jarvi et al. 2004, p. 2,166;
Foster et al. 2007, p. 4,744); both attributes suggest that iiwi may
have historically experienced a drastic reduction in population size
that led to a genetic bottleneck. Studies have also found low diversity
in the antigen-binding sites of the iiwi's major histocompatibility
complex (that part of an organism's immune system that helps to
recognize foreign or incompatible proteins (antigens) and trigger an
immune response).
The relationship between temperature and avian malaria is of
extreme importance to the current persistence of iiwi and the viability
of the species in the future. The development of the Plasmodium
parasite that carries malaria responds positively to increased
temperature, such that malaria transmission is greatest in warm, low-
elevation forests with an average temperature of 72[emsp14][deg]F (22
[deg]C), and is largely absent in high-elevation forests above 4,921 ft
(1,500 m) with cooler mean annual temperatures around 57[emsp14][deg]F
(14 [deg]C) (Ahumada et al. 2004, p. 1,167; LaPointe et al. 2010, p.
318; Liao et al. 2015, p. 4,343). High-elevation forests thus currently
serve as disease-free habitat zones for Hawaiian forest birds,
including iiwi. Once one of the most common birds in forests throughout
the Hawaiian islands, iiwi are now rarely found at lower elevations,
and are increasingly restricted to high-elevation mesic and wet forests
where cooler temperatures limit both the development of the malarial
parasite and mosquito densities (Scott et al.
[[Page 64419]]
1986, pp. 367-368; Ahumada et al. 2004, p. 1,167; LaPointe et al. 2010,
p. 318; Samuel et al. 2011, p. 2,960; Liao et al. 2015, p. 4,346;
Samuel et al. 2015, p. 14).
Temperature also affects the life cycle of the malaria mosquito
vector, Culex quinquefasciatus. Lower temperatures slow the development
of larval stages and can affect the survival of adults (Ahumada et al.
2005, pp. 1,165-1,168; LaPointe et al. 2012, p. 217). Although closely
tied to altitude and a corresponding decrease in temperature, the
actual range of mosquitoes varies with season. Generally, as
temperature decreases with increasing elevation, mosquito abundance
drops significantly at higher altitudes. In the Hawaiian Islands, the
mosquito boundary occurs between 4,921 and 5,577 ft (1,500 and 1,700 m)
(VanRiper et al. 1986, p. 338; LaPointe et al. 2012, p. 218). Areas
above this elevation are at least seasonally relatively free of
mosquitoes, thus malaria transmission is unlikely at these high
elevations under current conditions.
Early on, Ralph and Fancy (1995, p. 741) and Atkinson et al. (1995,
p. S66) suggested that the seasonal movements of iiwi to lower
elevation areas where ohia is flowering may result in increased contact
with malaria-infected mosquitoes, which, combined with the iiwi's high
susceptibility to the disease, may explain their observed low annual
survivorship relative to other native Hawaiian birds. Compounding the
issue, other bird species, which overlap with iiwi in habitat,
including Apapane (Himatione sanguinea), are relatively resistant to
the diseases and carry both Plasmodium and avian pox virus. As
reservoirs, they carry these diseases upslope where mosquitoes are less
abundant but still occur in numbers sufficient to facilitate and
continue transmission to iiwi (Ralph and Fancy 1995, p. 741).
Subsequent studies have confirmed the correlation between risk of
malaria infection and iiwi altitudinal migrations, and suggest upper
elevation forest reserves in Hawaii may not adequately protect mobile
nectarivores such as iiwi. Kuntz (2008, p. 3) found iiwi populations at
upper elevation study sites (6,300 ft (1,920 m)) declined during the
non-breeding season when birds departed for lower elevations in search
of flowering ohia, traveling up to 12 mi (19.4 km) over contiguous
mosquito-infested wet forest. Guillamet et al. (2015, p. 192) used
empirical measures of seasonal movement patterns in iiwi to model how
movement across elevations increases the risk of disease exposure, even
affecting breeding populations in disease-free areas. La Pointe et al.
(unpublished data 2015) found that, based on malaria prevalence in all
Hawaiian forest birds, species migrating between upper elevations to
lower elevations increased their risk of exposure to avian malaria by
as much as 27 times. The greater risk was shown to be due to a much
higher abundance of mosquitoes at lower elevations, which in turn was
attributable at least in part to the higher abundance of pigs and their
activities in lower elevation forests (discussed further below).
Avian Pox
Avian pox (or bird pox) is an infection caused by the virus
Avipoxvirus, which produces large, granular, and eventually necrotic
lesions or tumors on exposed skin or diphtheritic lesions on the mouth,
trachea, and esophagus of infected birds. Avian pox can be transmitted
through cuts or wounds upon physical contact or through the mouth parts
of blood-sucking insects such as the mosquito Culex quinquefasciatus,
the common vector for both the pox virus and avian malaria (LaPointe et
al. 2012, p. 221). Tumors or lesions caused by avian pox can be
crippling for birds, and may result in death. Although not extensively
studied, existing data suggest that mortality from avian pox may range
from 4 to 10 percent observed in Oahu Elepaio (Chasiempis ibidis) (for
birds with active lesions (VanderWerf 2009, p. 743) to 100 percent in
Laysan finches (Warner 1968, p. 108). VanderWerf (2009, p. 743) has
also suggested that mortality levels from pox may correlate with higher
rainfall years, and at least in the case of the Elepaio, observed
mortality may decrease over time with a reduction in susceptible birds.
As early as 1902 native birds suffering from avian pox were
observed in the Hawaiian Islands, and Warner (1968, p. 106) described
reports that epizootics of avian pox ``were so numerous and extreme
that large numbers of diseased and badly debilitated birds could be
observed in the field.'' As the initial wave of post-European
extinctions of native Hawaiian birds was largely observed in the late
1800s, prior to the introduction of avian malaria (Van Riper et al.
1986, p. 342), it is possible that avian pox played a significant role,
although there is no direct evidence (Warner 1968, p. 106). Molecular
work has revealed two genetically distinct variants of the pox virus
affecting forest birds in Hawaii that differ in virulence (Jarvi et al.
2008, p. 347): One tends to produce fatal lesions, and the other
appears to be less severe, based on the observation of recurring pox
infections in birds with healed lesions (Atkinson et al. 2009, p. 56).
The largest study of avian pox in scope and scale took place
between 1977 and 1980, during which approximately 15,000 native and
nonnative forest birds were captured and examined for pox virus lesions
from 16 different locations on transects along Mauna Loa on Hawaii
Island (Van Riper et al. 2002, pp. 929-942). The study made several
important determinations, including that native forest birds were
indeed more susceptible than introduced species, that all species were
more likely to be infected during the wet season, and that pox
prevalence was greatest at mid-elevation sites approximately 3,937 ft
(1,200 m) in elevation, coinciding with the greatest overlap between
birds and the mosquito vector. Of the 107 iiwi captured and examined
during the study, 17 percent showed signs of either active or inactive
pox lesions (Van Riper et al. 2002, p. 932). Many studies of avian pox
have documented that native birds are frequently infected with both
avian pox and avian malaria (Van Riper et al. 1986, p. 331; Atkinson et
al. 2005, p. 537; Jarvi et al. 2008, p. 347). This may be due to
mosquito transmission of both pathogens simultaneously, because
documented immune system suppression by the pox virus renders
chronically infected birds more vulnerable to infection by, or a
relapse of, malaria (Jarvi et al. 2008, p. 347), or due to other
unknown factors. The relative frequency with which the two diseases co-
occur makes it challenging to disentangle the independent impact of
either stressor acting alone (LaPointe et al. 2012, p. 221), and we
lack any indication of the degree to which pox may be a specific threat
to iiwi or contributing to its decline.
Compounded Impacts--Feral Ungulates Create Habitat for Culex
quinquefasciatus Mosquitoes and Exacerbate Impacts of Disease
It has been widely established that damage to native tree ferns
(Cibotium spp.) and rooting and wallowing activity by feral pigs create
mosquito larval breeding sites in Hawaiian forests where they would not
otherwise occur. The porous geology and relative absence of puddles,
ponds, and slow-moving streams in most Hawaiian landscapes precludes an
abundance of water-holding habitat sites for mosquito larvae; however,
Culex quinquefasciatus mosquitoes, the sole vector for avian malaria in
Hawaii, now occur in great density in many wet forests where their
larvae primarily rely on habitats created by pig activity (LaPointe
2006, pp. 1-3;
[[Page 64420]]
Ahumada et al. 2009, p. 354; Atkinson and LaPointe 2009, p. 60; Samuel
et al. 2011, p. 2,971). Pigs compact volcanic soils and create wallows
and water containers within downed, hollowed-out tree ferns, knocked
over and consumed for their starchy pith (Scott et al. 1986, pp. 365-
368; Atkinson et al. 1995, p. S68). The abundance of C.
quinquefasciatus mosquitoes is also much greater in suburban and
agricultural areas than in undisturbed native forest, and the mosquito
is capable of dispersing up to 1 mile (1.6 kilometers) within closed-
canopy native forest, including habitat occupied by the iiwi (LaPointe
2006, p. 3; LaPointe et al. 2009, p. 409).
In studies of native forest plots where feral ungulates (including
pigs) were removed by trapping and other methods, researchers have
demonstrated a correlation in the abundance of Culex spp. mosquitoes
when comparing pig-free, fenced areas to adjacent sites where feral pig
activity is unmanaged. Aruch et al. 2007 (p. 574), LaPointe 2006 (pp.
1-3) and LaPointe et al. (2009, p. 409; 2012, pp. 215, 219) assert that
management of feral pigs may be strategic to managing avian malaria and
pox, particularly in remote Hawaiian rain forests where studies have
documented that habitats created by pigs are the most abundant and
productive habitat for larval mosquitoes. Studies suggest that
reduction in mosquito habitat must involve pig management across large
landscapes due to the tremendous dispersal ability of C.
quinquefasciatus and the possibility of the species invading from
adjacent areas lacking management (LaPointe 2006, pp. 3-4). The
consequences of feral pig activities thus further exacerbate the
impacts to iiwi from avian malaria and avian pox, by creating and
enhancing larval habitats for the mosquito vector, thereby increasing
exposure to these diseases.
Avian Diseases--Summary
The relatively recent introduction of avian pox and avian malaria,
in concert with the introduction of the mosquito disease vector, is
widely viewed as one of the key factors underlying the loss and decline
of native forest birds throughout the Hawaiian Islands. Evolving in the
absence of mosquitoes and their vectored pathogens, native Hawaiian
forest birds, particularly honeycreepers such as iiwi, lack natural
immunity or genetic resistance, and thus are more susceptible to these
diseases than are nonnative bird species (van Riper et al. 1986, pp.
327-328; Yorinks and Atkinson 2000, p. 737). Researchers consider iiwi
one of the most vulnerable species, with studies showing an average of
95 percent mortality in response to infection with avian malaria
(Atkinson et al. 1995, p. S63; Samuel et al. 2015, p. 2). Many native
forest birds, including iiwi, are now absent from warm, low-elevation
areas that support large populations of disease-carrying mosquitoes,
and these birds persist only in relatively disease-free zones in high-
elevation forests, above roughly 4,921 to 5,577 ft (1,500 to 1,700 m),
where both the development of the malarial parasite and the density of
mosquito populations are held in check by cooler temperatures (Scott et
al. 1986, pp. 85, 100, 365-368; Woodworth et al. 2009, p. 1,531; Liao
et al. 2015, pp. 4,342-4,343; Samuel et al. 2015, pp. 11-12). Even at
these elevations, however, disease transmission may occur when iiwi
move downslope to forage on ephemeral patches of flowering ohia in the
nonbreeding season, encountering disease-carrying mosquitoes in the
process (Ralph and Fancy 1995, p. 741; Fancy and Ralph 1998, p. 3;
Guillaumet et al. 2015, p. EV-8; LaPointe et al. 2015, p. 1). Iiwi have
not demonstrably developed resistance to avian malaria, unlike related
honeycreepers including Amakihi (Hemignathus spp.) and Apapane. Due to
the known extreme mortality rate of iiwi when exposed to avian malaria,
we consider avian malaria in particular to pose a threat to iiwi.
Having already experienced local extinctions and widespread population
declines, it is possible that the species may not possess sufficient
genetic diversity to adapt to these diseases (Atkinson et al. 2009, p.
58).
Climate Change
Based on the assessment of the best scientific data available in
our species status report, we concluded that climate change exacerbates
the impacts to iiwi from mosquito-borne disease, and this effect is
likely to continue and worsen in the future. Air temperature in Hawaii
has increased in the past century and particularly since the 1970s,
with the greatest increases at higher elevations, and several
conservative climate change models project continued warming in Hawaii
into the future. As a result, the temperature barrier to the
development and transmission of avian malaria will continue to move up
in elevation in response to warmer conditions, leading to the
curtailment or loss of disease-free habitats for iiwi. We briefly
discuss below three climate studies that conservatively predict the
iiwi will lose between 60 and 90 percent of its current (and already
limited) disease-free range by the end of this century, with
significant effects occurring by mid-century.
Climate Change Effects on Iiwi
Climate change is a stressor that is likely to significantly
exacerbate the effects of avian malaria on iiwi both directly through
increased prevalence and mortality, and indirectly through the loss of
disease-free habitat. Air temperature in Hawaii has increased in the
past century and particularly since the 1970s, with greater increases
at high elevation (Giambelluca et al. 2008, pp. 2-4; Wang et al. 2014,
pp. 95, 97). Documented impacts of increased temperature include the
prevalence of avian malaria in forest birds at increasing elevation,
including high-elevation sites where iiwi are already declining, for
example, on Kauai (Paxton et al. 2013, p. 13). Several projections for
future climate in Hawaii describe a continued warming trend, especially
at high elevations. In our species status report, we analyzed in
particular three climate studies (summarized below) that address the
future of native forest birds, including iiwi, in the face of the
interactions between climate change and avian malaria.
Benning et al. (2002) concluded that under optimistic assumptions
(i.e., 3.6 [deg]F (2 [deg]C) increase in temperature by the year 2100),
malaria-susceptible Hawaiian forest birds, including iiwi, will lose
most of their disease-free habitat in the three sites they considered
in their projection of climate change impacts. For example, current
disease-free habitat at high elevation within the Hakalau Forest
National Wildlife Refuge (NWR) on the island of Hawaii (where the
environment is still too cold for development of the malarial parasite)
would be reduced by 96 percent by the end of the century.
Fortini et al. (2015) conducted a vulnerability assessment for 20
species of Hawaiian forest birds based on a projected increase of 6.1
[deg]F (3.4 [deg]C) under the A1B emissions scenario at higher
elevations by 2100. Even under this relatively optimistic scenario, in
which emissions decline after mid-century (IPCC 2007, p. 44), all
species were projected to suffer range loss as the result of increased
transmission of avian malaria at higher elevations with increasing
temperature. Iiwi was predicted to lose 60 percent of its current range
by the year 2100, and climate conditions suitable for the species will
shift up in elevation, including into areas that are not currently
forested, such as lava flows and high-elevation grasslands. Most of the
remaining habitat for iiwi would be
[[Page 64421]]
restricted to a single island, Hawaii Island.
Liao et al. (2015) generated temperature and precipitation
projections under three alternative emissions scenarios and projected
future malaria risk for Hawaiian forest birds. Irrespective of the
scenario modeled, by mid-century (roughly 2040), malaria transmission
rates and impacts to bird populations began increasing at high
elevations. By 2100, the increased annual malaria transmission rate for
iiwi was projected to result in population declines of 70 to 90 percent
for the species, depending on the emissions scenario.
All three of these studies consistently predict a significant loss
of disease-free habitat for iiwi with consequent severe reductions in
population size and distribution by the year 2100, with significant
changes likely to be observed as early as 2040. As the iiwi's numbers
and distribution continue to decline, the remaining small, isolated
populations become increasingly vulnerable to loss of ohia forest
habitat from other stressors such as rapid ohia death, as well as other
environmental catastrophes and demographic stochasticity, particularly
should all remaining iiwi become restricted to a single island (Hawaii
Island), as some scenarios suggest.
Climate change will likely exacerbate other stressors to iiwi in
addition to disease. Changes in the amount and distribution of rainfall
in Hawaii likely will affect the quality and extent of mesic and wet
forests on which iiwi depend. However, changes in the trade wind
inversion (which strongly influences rainfall) and other aspects of
precipitation with climate change are difficult to model with
confidence (Chu and Chen 2005, pp. 4,801-4,802; Cao et al. 2007, pp.
1,158-1,159; Timm et al. 2015, p. 107; Fortini et al. 2015, p. 5; Liao
et al. 2015, p. 4,345). In addition, potential increases in storm
frequency and intensity in Hawaii as a result of climate change may
lead to an increase in direct mortality of individual iiwi and a
decline in the species' reproductive success. Currently, no well-
developed projections exist for these possible cumulative effects.
Climate Change--Summary
The natural susceptibility of native forest birds to introduced
diseases, in combination with the observed restriction of Hawaiian
honeycreepers to high-elevation forests, led Atkinson et al. (1995, p.
S68) to predict two decades ago that a shift in the current mosquito
distribution to higher elevations could be ``disastrous for those
species with already reduced populations.'' Thus, climate change has
significant implications for the future of Hawaiian forest birds, as
predictions suggest increased temperatures may largely eliminate the
high-elevation forest currently inhospitable to the transmission of
mosquito-borne diseases (Benning et al. 2002, pp. 14,247-14,249;
LaPointe et al. 2012, p. 219; Fortini et al. 2015, p. 9). Samuel et al.
(2015, p. 15) predict further reductions and extinctions of native
Hawaiian birds as a consequence, noting that the iiwi is particularly
vulnerable due to its high susceptibility to malaria. Several
independent studies project consistently significant negative impacts
to the iiwi as a result of climate change and the increased exposure to
avian malaria as disease-free habitats shrink. As iiwi are known to
exhibit 95 percent mortality on average as a result of avian malaria,
the current numbers of iiwi are of little consequence should all or
most of the remaining individuals become exposed to the disease in the
future.
Rapid Ohia Death
Our species status report identified rapid ohia death (ROD), a type
of Ceratosystis spp. vascular wilt (fungal) disease, as a factor with
the potential to exacerbate the impacts currently affecting iiwi
habitat and reduce the amount of disease-free habitat remaining by
destroying high-elevation ohia forest. ROD was first detected in 2012
as ohia trees began mysteriously dying within lowland forests of the
Puna Region of Hawaii Island. In June 2015, researchers identified the
disease as ROD with an estimated area at the time of 15,000 ac (6,070
ha) of infected ohia trees (Keith et al. 2015, pp. 1-2). ROD affects
non-contiguous ohia forest stands ranging in size from <1 ac (<0.4 ha)
up to 247 ac (100 ha) with nearly all trees in these areas infected. At
present the disease remains restricted to Hawaii island, with the
largest affected area within the Puna District, where infected trees
have been observed within approximately 4,000 discontinuous acres
(1,619 ha) (Hughes 2016, pers. comm.). Based upon the most recent
research, ROD-infected stands of ohia often initially show greater than
50 percent mortality, and within 2 to 3 years nearly 100 percent of
trees in a stand succumb to the disease (College of Tropical
Agriculture and Human Resources 2016 (http://www2.ctahr.hawaii.edu/forestry/disease/ohia_wilt.html)).
Affected trees are found at elevations ranging from sea level up to
approximately 5,000 ft (1,524 m), including at Wailuku Forest near
Hakalau Forest NWR (Hughes 2016, pers. comm.), which contains a stable
to increasing iiwi population (Paxton et al. 2013, p. 12). As of March
2016, the amount of forest area affected on Hawaii Island is estimated
to be approximately 34,000 ac (13,759 ha) (Hughes 2016, pers. comm.).
Two different strains of the virus appear to be responsible for ROD
(Hughes 2016, pers. comm.). These estimates demonstrate that the amount
of ohia forest on Hawaii Island infected by ROD more than doubled
between 2015 and 2016. While ROD is presently reported only from the
island of Hawaii, it has spread across a large portion of the island,
which is home to 90 percent of the current iiwi population. In some
areas, affected trees have been observed within the range of iiwi
(Hughes 2016, pers. comm.). Hawaii Island is particularly important for
the future of iiwi, as iiwi are predicted to be largely if not entirely
restricted to that island under some future climate change projections
(Fortini et al. 2015, p. 9, Supplement 6).
Evaluation of Existing Regulatory Mechanisms and Conservation Measures
Our species status report evaluated several regulatory and other
measures in place today that might address or are otherwise intended to
ameliorate the stressors to iiwi. Our analysis concluded that forest
habitat protection, conservation, and restoration has the potential to
benefit iiwi by protecting and enhancing breeding and foraging areas
for the species while simultaneously reducing the abundance of mosquito
breeding sites, despite the disease vector's (Culex quinquefasciatus)
1-mi (1.6-km) dispersal ability (LaPointe et al. 2009, pp. 408; 411-
412; LaPointe et al. 2012, p. 215).
Efforts to restore and manage large, contiguous tracts of native
forests have been shown to benefit iiwi, especially when combined with
fencing and ungulate removal (LaPointe et al. 2009, p. 412; LaPointe et
al. 2012, p. 219). While forest restoration and ungulate management at
the Hakalau Forest NWR on Hawaii Island are excellent examples of what
is needed to increase iiwi abundance, many similar large-scale projects
would be necessary rangewide to simply reduce mosquito abundance and
protect the species from current habitat threats alone. However, even
wide-scale landscape habitat management would be unable to fully
address the present scope of the threat of disease, and sufficient
high-elevation forest is not available to provide disease-free habitat
for iiwi in the face
[[Page 64422]]
of future climate change. Even if disease-free habitat within managed
areas could be restored and protected now, much of this habitat will
lose its disease-free status as avian malaria moves upward in elevation
in response to warming temperatures, as is occurring already within the
Alakai Wilderness on the island of Kauai.
New opportunities are emerging, such as large-scale vector control
using new genetics technology, that have the potential to assist
Hawaiian forest birds (LaPointe et al. 2009, pp. 416-417; Reeves et al.
2014, p. e97557; Gantz et al. 2015, pp. E6736-E6743). These tools
include the potential introduction of sterile male mosquitoes and
transgenic insect techniques that introduce new genetic material into
mosquito populations, including self-sustaining genes that will help
drive an increase of the new desirable trait, i.e., inability or
decreased ability to transmit diseases throughout a mosquito
population, thereby improving long-term transmission control. While
promising, our report concludes that these new technologies for
achieving large-scale control or eradication of mosquitoes in Hawaii
are still in the research and planning stage and have yet to be
implemented or proven effective.
Our species status report also evaluated several regulations and
agreements pertaining to climate change. Although the United States and
some other countries have passed some regulations specifically intended
to reduce the emission of greenhouse gases that contribute to climate
change, the scope and effect of such regulations are limited. Indeed,
during the United Nations Framework Convention on Climate Change
(UNFCCC) meeting in December 2015, the UNFCCC indicated that, even if
all the member countries' intended contributions to greenhouse gas
reductions were fully implemented and targets met, the goal of limiting
the increase in global average temperature to 2 [deg]C
(3.6[emsp14][deg]F) by the year 2100 would not be achieved.
Many of the efforts to tackle the primary stressors to iiwi are
still in the research and development stage, or are implemented only on
a small or limited scale. Because the primary stressor, avian malaria,
continues to have negative impacts, and these impacts are exacerbated
by climate change, we must conclude that no current conservation
measures or regulations are sufficient to offset these impacts to the
species.
Summary of Biological Status and Threats
We have reviewed the best scientific and commercial data available
regarding iiwi populations and the stressors that affect the species.
This information includes, notably, a recent comprehensive analysis of
iiwi abundance, distribution, and population trends (Paxton et al.
2013); numerous studies that provide information on the particularly
high mortality of iiwi in response to avian malaria; and recent models
examining the current relationship between climate and malaria, as well
as the likely future consequences of climate change for iiwi and other
Hawaiian forest birds (including Benning et al. 2002, Fortini et al.
2013, and Liao et al. 2015). Our review also reflects the expert
opinion of the species' status report team members, and input provided
by specialists familiar with avian malaria and iiwi genetics. We direct
the reader to the draft iiwi species status report for our detailed
evaluation of the biological status of the iiwi and the influences that
may affect its continued existence.
Once one of the most common of the native Hawaiian forest birds,
the iiwi has declined across large portions of its range, has been
extirpated or nearly so from some islands, and many of the few
remaining populations are declining. The iiwi's range is contracting
upslope in most areas, and population declines and range contraction
are concurrent with increasing prevalence of avian malaria. Clear
evidence exists that the iiwi is highly susceptible to avian malaria,
and that the prevalence of this disease is moving upslope in Hawaiian
forests correlated with temperature increases associated with global
climate change. The evidence suggests this disease and its trend of
increasing prevalence at increasing elevation are the chief drivers of
observed iiwi population declines and range contraction. Although
habitat management to reduce breeding habitat for mosquitoes may have
slowed the decline of iiwi and other forest birds to some degree in a
few locations, no landscape-scale plans or strategies exist for
eradicating mosquitoes or otherwise reducing the risk posed by avian
malaria to iiwi and other susceptible Hawaiian bird species.
The documented trend of temperature increase, which is greatest at
high elevation, is projected to continue at least through the 21st
century. The transmission of avian malaria is currently limited or
absent at higher elevations, where temperatures are too cool for the
development of the malaria parasite. However, multiple independent
modeling efforts consistently project that the prevalence of avian
malaria will continue to increase upslope with increasing temperature,
eventually eliminating most or all remaining disease-free habitat in
the islands. These models, which incorporate data on the distribution
of forest birds and on disease transmission, project moderate to high
avian malaria transmission at the highest elevations of the iiwi's
current range by the end of this century, with some significant effects
predicted within the next few decades. As a consequence, significant
declines in iiwi populations are projected, on the order of 70 to 90
percent by 2100, depending on the future climate scenario.
The impacts of other stressors to iiwi, such as loss or degradation
of native forest by nonnative species (disturbance or destruction by
feral ungulates; invasion by nonnative plants; impacts from nonnative
pathogens such as ROD), predation by rats and other nonnative
predators, and small-population stressors such as demographic
stochasticity and loss of genetic diversity, have not been well
documented or quantified. However, any stressors that result in further
degradation or fragmentation of the forests on which the iiwi relies
for foraging and nesting, or result in increased mortality or reduced
reproductive success, are likely to exacerbate the impacts of disease
on the species. The effects of climate change are likely to exacerbate
these other stressors to iiwi as well.
As the number and distribution of iiwi continue to decline, the
remaining small, isolated populations become increasingly vulnerable to
environmental catastrophes and demographic stochasticity; this will
particularly be the case should all remaining iiwi become restricted to
Hawaii Island, as some modeling scenarios suggest. Ninety percent of
the rangewide iiwi population is already restricted to Hawaii Island,
where ROD has recently emerged as a fast-moving threat to the already
limited ohia forest habitat required by iiwi.
In consideration of all of this information, we conclude that avian
malaria, as exacerbated by the ongoing effects of climate change, poses
a threat to iiwi, and the action of these stressors places the species
as a whole at an elevated risk of extinction. Because the vast majority
of the remaining iiwi population is restricted to the island of Hawaii,
we consider rapid ohia death to pose a threat to the future viability
of iiwi as well, as it may result in major loss of forest within the
iiwi's remaining range on that island.
[[Page 64423]]
Determination
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations in title 50 of the Code of Federal 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 list a species based on (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.
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the iiwi. As described in the species status report, in considering
the five listing factors, we evaluated many potential stressors to
iiwi, including but not limited to: Stressors that may affect the
extent or quality of the bird's ohia forest habitat (ohia dieback, ohia
rust, ROD, drought, fires, volcanic eruptions, nonnative plants, and
feral ungulates), introduced diseases, predation by introduced mammals,
competition with nonnative birds, ectoparasites, climate change, and
the effects of small population size. Based on our assessment,
disease--particularly avian malaria--is the primary driver in the
ongoing declines in abundance and range of iiwi, and climate change
substantially exacerbates the impact of disease on the species and will
continue to do so into the future.
The greatest current threat to iiwi comes from exposure to
introduced diseases carried by nonnative mosquitoes (Factor C). Avian
malaria in particular has been clearly demonstrated to result in
extremely high mortality of iiwi; avian pox may have significant
effects on iiwi as well, although the evidence is not as clear or
measurable. These diseases have resulted in significant losses of the
once ubiquitous iiwi, which remains highly susceptible and, as of
present, shows no clear indication of having developed substantial
resistance or tolerance. Exposure to these diseases is ongoing, and is
expected to increase as a consequence of the effects of climate change
(Factor E).
Several climate model projections predict that continued increases
in temperature due to climate change will greatly exacerbate the
impacts of avian diseases upon iiwi due to loss of disease-free
habitat. Several iiwi populations, including those on Molokai, Kauai,
West Maui, and possibly Oahu--all lower in elevation than East Maui and
Hawaii Island--are already extremely small in size or are represented
by only a few occasional individuals, probably owing to the loss of
disease-free habitat. Iiwi may face extirpation in these places due to
the inability to overcome the effects of malaria. The species is
expected to first become restricted to Hawaii Island, perhaps by the
year 2040. By the end of the century, the existence of iiwi is
uncertain due to the ongoing loss of disease-free habitat; the
potential impacts to ohia forests from ROD and other stressors could
increase the risk to iiwi as well. These threats to iiwi are ongoing,
most are rangewide, are expected to increase in the future, and are
significant because they will likely result in increased mortality of
iiwi and loss of remaining populations, as well as further decreases in
the availability and amount of disease-free habitat at high elevation.
As discussed above, current regulatory mechanisms are not sufficient to
address these threats (Factor D).
Some of the other stressors contributed to past declines in iiwi,
or negatively affect the species or its habitat today; however, of the
additional stressors considered, we found no information to suggest
that any is currently a key factor in the ongoing declines in abundance
and range of iiwi, although they may be contributing or exacerbating
factors. Habitat loss and alteration (Factor A) caused by nonnative
plants and ungulates is occurring rangewide, has resulted in degraded
ohia forest habitat, and is not likely to be reduced in the future.
While ohia forests still comprise the majority of native forest cover
on most of the main Hawaiian Islands, climate change and its likely
effects, such as increased drought frequency, are expected to further
affect ohia forest habitat and compound other impacts, including the
spread of invasive plants and perhaps the severity and frequency of
ohia diseases. In particular, the rapidly spreading and highly lethal
disease, rapid ohia death, poses an increasing risk to the native
forest habitat of iiwi on Hawaii Island, where 90 percent of remaining
iiwi occur. This emerging factor has the potential to exacerbate avian
disease and other stressors in the future by accelerating the loss and
degradation of iiwi's habitat. If this disease becomes widespread, it
could further increase the vulnerability of the iiwi by eliminating the
native forest it requires for foraging and nesting.
We do not have any information that overutilization for commercial,
recreational, scientific, or educational purposes (Factor B) poses a
threat to iiwi.
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' We considered whether the iiwi meets
either of these definitions, and find that the iiwi meets the
definition of a threatened species for the reasons described below.
We considered whether the iiwi is presently in danger of extinction
and determined that proposing endangered status is not appropriate.
Although the species has experienced significant reductions in both
abundance and range, at the present time the species is still found on
multiple islands and the species as a whole still occurs in relatively
high numbers. Additionally, disease-free habitat currently remains
available for iiwi in high-elevation ohia forests with temperatures
sufficiently cool to prevent the development of the malarial parasite.
For these reasons, we do not consider the iiwi to be in imminent danger
of extinction, although this formerly common species has experienced
threats of such severity and magnitude that it has now become highly
vulnerable to continued decline and local extirpation, such that the
species is likely to become endangered within the foreseeable future,
as explained below.
Based on our review of the best scientific and commercial data
available, we expect that additional iiwi population declines will be
observed range-wide within the next few decades, and indications are
that declines are already taking place on Kauai and in some Maui and
Hawaii Island populations as a result of increasing temperatures and
consequent exposure to avian malaria at some elevations where the
disease is uncommon or absent today. Iiwi has a very high observed
mortality rate when exposed to avian malaria, and the warming effects
of climate change will result in increased exposure of the remaining
iiwi populations to this disease, especially at high elevation. Peer-
reviewed results of modeling experiments project that malaria
transmission rates and effects on iiwi populations will begin
increasing at high elevations by mid-century, and
[[Page 64424]]
result in population declines of 70 to 90 percent by the year 2100. We
thus conclude that the iiwi is likely to become in danger of extinction
throughout all of its range within the foreseeable future. Because the
iiwi is not in imminent danger of extinction, but is likely to become
in danger of extinction within the foreseeable future, it meets the
definition of a threatened species. Therefore, on the basis of the best
available scientific and commercial information, we propose listing the
iiwi as threatened in accordance with sections 3(20) and 4(a)(1) of the
Act.
Under the Act and our implementing regulations, a species may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. Because we have determined that the
iiwi is threatened throughout all of its range, no portion of its range
can be ``significant'' for purposes of the definitions of ``endangered
species'' and ``threatened species.'' See the Final Policy on
Interpretation of the Phrase ``Significant Portion of Its Range'' in
the Endangered Species Act's Definitions of ``Endangered Species'' and
``Threatened Species'' (79 FR 37577; July 1, 2014).
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition from listing will result in public awareness and
conservation by Federal, State, Tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and other countries and calls for recovery actions to be carried
out for 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 calls for 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 and preparation of a draft and final
recovery plan. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan also identifies
recovery criteria for review of when a species may be ready for
downlisting or delisting, and methods for monitoring recovery 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
other qualified persons) are often established to develop recovery
plans. When completed, the recovery outline, draft recovery plan, and
the final recovery plan for iiwi will be available on our Web site
(http://www.fws.gov/endangered), or from our Pacific Islands Fish and
Wildlife Office (see FOR FURTHER INFORMATION CONTACT). The public will
have an opportunity to comment on the draft recovery plan, and the
Service will consider all information presented during the public
comment period prior to approval of the plan.
Implementation of recovery actions generally requires the
participation of a broad 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. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
If this species is listed, 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. In addition,
pursuant to section 6 of the Act, the State of Hawaii would be eligible
for Federal funds to implement management actions that promote the
protection or recovery of the iiwi. Information on our grant programs
that are available to aid species recovery can be found at: http://www.fws.gov/grants.
Although the iiwi is only proposed for listing under the Act at
this time, please let us know if you are interested in participating in
recovery efforts for this species. Additionally, we invite you to
submit any new information on this species whenever it becomes
available and any information you may have for recovery planning
purposes (see FOR FURTHER INFORMATION CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as an
endangered or threatened species and with respect to its critical
habitat, if any is designated. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) of the Act requires Federal agencies to
confer with the Service 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 the
species or 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 consultation with the
Service.
Federal agency actions within the iiwi's habitat that may require a
conference or consultation or both as described in the preceding
paragraph, include but are not limited to, management and any other
landscape-altering activities on Federal lands administered by the U.S.
Fish and Wildlife Service, U.S. Forest Service, and National Park
Service; actions within the jurisdiction of the Natural Resources
Conservation Service, the U.S. Army Corps of Engineers, the U.S. Fish
and Wildlife Service, and branches of the Department of Defense (DOD);
and activities funded or authorized under the Federal Highway
Administration, Partners for Fish and Wildlife Program, and DOD
construction activities related to training or other military missions.
Under section 4(d) of the Act, the Service has discretion to issue
regulations that we find necessary and advisable to provide for the
conservation of threatened species. We are not proposing to issue a
special rule
[[Page 64425]]
pursuant to section 4(d) for this species. Therefore, the provisions of
50 CFR 17.31(a) and (b) would apply. These regulatory provisions apply
the prohibitions of section 9(a)(1) of the Act to threatened wildlife
and make it illegal for any person subject to the jurisdiction of the
United States to take (which includes harass, harm, pursue, hunt,
shoot, wound, kill, trap, capture, or collect; or to attempt any of
these) threatened wildlife within the United States or on the high
seas. In addition, it is unlawful to import; 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 is also illegal to possess,
sell, deliver, carry, transport, or ship any such wildlife that has
been taken illegally. Certain exceptions apply to employees of the
Service, the National Marine Fisheries Service, other Federal land
management agencies, and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving threatened wildlife under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.32. With regard to
threatened wildlife, a permit may be issued for the following purposes:
For scientific purposes, to enhance the propagation or survival of the
species, or for incidental take in connection with otherwise lawful
activities. There are also certain statutory exemptions from the
prohibitions, which are found in sections 9 and 10 of the Act.
It is our policy, as 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. The intent of this
policy is to increase public awareness of the effect of a proposed
listing on proposed and ongoing activities within the range of the
species proposed for listing. Based on the best available information,
actions that may result in a violation of section 9 include but are not
limited to:
(1) Development of land or the conversion of native ohia forest,
including the construction of any infrastructure (e.g., roads, bridges,
railroads, pipelines, utilities) in occupied iiwi habitat;
(2) Unauthorized collecting, handling, possessing, selling,
delivering, carrying, or transporting of the species, including import
or export across State lines and international boundaries, except for
properly documented antique specimens of this species at least 100
years old, as defined by section 10(h)(1) of the Act;
(3) Introduction of nonnative species that compete with or prey
upon the iiwi, such as the new introduction of nonnative predators or
competing birds to the State of Hawaii; and
(4) Certain research activities: Collection and handling of iiwi
for research that may result in displacement or death of individuals.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Pacific
Islands Fish and Wildlife Office, Ecological Services Field Office (see
FOR FURTHER INFORMATION CONTACT).
Required Determinations
Clarity of the 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:
(1) Be logically organized;
(2) Use the active voice to address readers directly;
(3) Use clear language rather than jargon;
(4) Be divided into short sections and sentences; and
(5) 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 ADDRESSES. To better help us
revise the rule, your comments should be as specific as possible. For
example, you should tell us the numbers 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.
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be
prepared in connection with listing a species as an endangered or
threatened species under the Endangered Species 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 references cited in this rulemaking is available
on the Internet at http://www.regulations.gov at Docket No. FWS-R1-ES-
2016-0057 and upon request from the Pacific Islands Fish and Wildlife
Office (see FOR FURTHER INFORMATION CONTACT).
Authors
The primary authors of this proposed rule are the staff members of
the Pacific Islands Fish and Wildlife Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, we propose to amend part 17, subchapter B of chapter
I, title 50 of the Code of Federal Regulations, as set forth below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245; unless
otherwise noted.
0
2. In Sec. 17.11(h), add an entry for ``Iiwi (honeycreeper)'' to the
List of Endangered and Threatened Wildlife in alphabetical order under
BIRDS to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
----------------------------------------------------------------------------------------------------------------
Listing citations
Common name Scientific name Where listed Status and applicable
rules
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Birds
[[Page 64426]]
* * * * * * *
Iiwi (honeycreeper).............. Drepanis coccinea.. Wherever found..... T [Federal Register
citation when
published as a
final rule].
* * * * * * *
----------------------------------------------------------------------------------------------------------------
Dated: September 2, 2016.
Bryan Arroyo,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2016-22592 Filed 9-19-16; 8:45 am]
BILLING CODE 4333-15-P