[Federal Register: April 30, 2001 (Volume 66, Number 83)]
[Rules and Regulations]
[Page 21449-21489]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30ap01-14]
[[Page 21449]]
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Part II
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; Final Determination of
Critical Habitat for the Bay Checkerspot Butterfly (Euphydryas editha
bayensis); Final Rule
[[Page 21450]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AH61
Endangered and Threatened Wildlife and Plants; Final
Determination of Critical Habitat for the Bay Checkerspot Butterfly
(Euphydryas editha bayensis)
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service),
designate critical habitat for the bay checkerspot butterfly
(Euphydryas editha bayensis) (bay checkerspot), pursuant to the
Endangered Species Act of 1973, as amended (Act). A total of
approximately 9,673 hectares (23,903 acres) in San Mateo and Santa
Clara counties, California, is designated as critical habitat.
Critical habitat identifies specific areas that have the physical
and biological features that are essential to the conservation of a
listed species, and that may require special management considerations
or protection. The primary constituent elements for the bay checkerspot
are one or more of the following: stands of Plantago erecta,
Castilleja exserta, or Castilleja densiflora; spring
flowers providing nectar; pollinators of the bay checkerspot's food and
nectar plants; soils derived from serpentinic rock; and space for
dispersal between habitable areas. In addition, the following are each
primary constituent elements to be conserved when present in
combination with one or more of the primary constituent elements above:
areas of open grassland, topography with varied slopes and aspects
providing surface conditions with warm and moderate to cool
temperatures during sunny spring days, stable holes or cracks in the
soil and surface rocks or rock outcrops, wetlands providing moisture
during times of spring drought.
In addition, the following are each primary constituent elements to
be conserved when present in combination with one or more of the
primary constituent elements above: areas of open grassland, topography
with varied slopes and aspects, stable holes or cracks in the soil and
surface rocks or rock outcrops, and wetlands providing moisture during
times of spring drought.
Section 7 of the Act prohibits destruction or adverse modification
of critical habitat by any activity funded, authorized, or carried out
by any Federal agency. Section 4 of the Act requires us to consider
economic and other impacts of specifying any particular area as
critical habitat. We solicited data and comments from the public on all
aspects of the proposed rule and economic analysis. We revised the
proposal to incorporate or address new information received during the
comment periods.
DATES: This rule becomes effective on May 30, 2001.
ADDRESSES: Comments and materials received, as well as
supporting documentation used in the preparation of this final rule,
will be available for public inspection, by appointment, during normal
business hours at the Sacramento Fish and Wildlife Office, U.S. Fish
and Wildlife Service, 2800 Cottage Way, Room W2605, Sacramento,
California 95825.
FOR FURTHER INFORMATION CONTACT: David Wright or Chris Nagano
at the address above (telephone 916/414-6600; facsimile 916/414-6712).
SUPPLEMENTARY INFORMATION:
Background
The bay checkerspot is a medium-sized butterfly with a wingspan of
about 5 centimeters (2 inches (in.)). The forewings have black bands
along all the veins on the upper wing surface, contrasting sharply with
bright red, yellow, and white spots. The bay checkerspot is 1 of about
20 subspecies of Euphydryas editha (Miller and Brown 1981), and
differs in physical appearance from other subspecies in a variety of
size, wing coloration, larval, and pupal characteristics (Howe 1975;
Mattoni et al. 1997). It differs from LuEsther's checkerspot
(Euphydryas editha luestherae), (a later-flying,
Pedicularis-feeding subspecies of Inner Coast Range chaparral
in central California), by being darker, and lacking a relatively
uninterrupted red band demarcating the outer third of the wing. The
black banding on the forewings of the bay checkerspot gives a more
checkered appearance than the smaller quino checkerspot butterfly
(Euphydryas editha quino) of southern California (Service
1998).
Recent publications have advocated renaming the bay checkerspot,
Euphydryas editha bayensis, as Euphydryas editha editha
for reasons of historical precedence (Mattoni et al. 1997;
Emmel et al. 1998). Mattoni and co-authors (1997) have also
suggested that Euphydryas editha editha ranges from the San
Francisco Bay area south to northern Santa Barbara County in
California, and includes both the populations commonly known as the bay
checkerspot and several populations south of Santa Clara County whose
subspecific status has been uncertain. If this expanded subspecific
assignment is accepted by the scientific community, it would represent
a range extension for the bay checkerspot. Until such time as we make
any new or revised determination on the taxonomy, in this final rule,
we treat the threatened bay checkerspot as occurring in San Francisco
Bay area counties, notably the counties of San Mateo and Santa Clara,
as described in the final rule for the subspecies (52 FR 35378).
The bay checkerspot formerly occurred around San Francisco Bay,
from Twin Peaks and San Bruno Mountain (west of the Bay) and Contra
Costa County (east of the Bay), south through Santa Clara County.
Before the introduction of invasive Eurasian grasses and other weeds in
the 1700s, its distribution may have been wider (Service 1998). In the
decades preceding listing, the decline of the bay checkerspot was
primarily attributed to loss of habitat and fragmentation of habitat
due to increasing urbanization. Drought and other extremes of weather
have also been implicated in bay checkerspot population declines
(Ehrlich et al. 1980; Service 1998). Recent research has
identified excess nitrogen deposition from polluted air as a threat to
bay checkerspot habitats, due to its fertilizing effect enhancing the
growth of invasive nonnative plants even in serpentine soil areas
(Weiss 1999).
Habitat of the bay checkerspot most commonly is found on shallow,
serpentine-derived or similarly droughty or infertile soils, which
support the butterfly's larval food plants and also includes nectar
sources for adults that may also occur on other adjacent soil types.
Serpentine soils are high in magnesium and low in calcium, and are a
strong indicator of habitat value for the bay checkerspot. The primary
larval host plant of the bay checkerspot is Plantago erecta
(dwarf plantain), an annual, native plantain. The bay checkerspot
usually is found associated with Plantago erecta in grasslands
on serpentine soils, such as soils in the Montara series. In Santa
Clara County, the Inks and Climara soil series are related soils and
often have inclusions of Montara (U.S. Soil Conservation Service 1974).
Henneke and other serpentine soils also occur within the range of the
bay checkerspot. Populations of the bay checkerspot formerly occurred
on San Bruno Mountain and other locations with soils that are not
serpentine. We believe this
[[Page 21451]]
indicates that, with otherwise suitable habitat conditions, the bay
checkerspot is capable of living in nonserpentine soil areas.
Serpentine soils are well known for harboring rare and endemic
plant species, and because the bay checkerspot inhabits serpentine
areas, our critical habitat designation for the bay checkerspot
overlaps habitat of several federally listed plant species: the San
Mateo thornmint (Acanthomintha obovata ssp. duttonii),
Santa Clara Valley dudleya (Dudleya setchellii), Coyote
ceanothus (Ceanothus ferrisae), Tiburon paintbrush
(Castilleja affinis ssp. neglecta), fountain thistle
(Cirsium fontinale var. fontinale), Marin dwarf flax
(Hesperolinon congestum), white-rayed pentachaeta
(Pentachaeta bellidiflora), and Metcalf Canyon jewelflower
(Streptanthus albidus ssp. albidus) (Service 1998).
However, bay checkerspot critical habitat does not include all the
habitat essential to any of these plant species. Bay checkerspot
critical habitat is also coincident with habitat for a number of rare
plants and animals that are not federally listed (Service 1998).
In many years, bay checkerspot larvae may use a secondary host
plant species, for instance, when dwarf plantain dries up while
prediapause larvae are still feeding. Castilleja
(Orthocarpus) densiflora (purple owl's-clover) and
Castilleja exserta (Orthocarpus purpurascens) (exserted
paintbrush) are known secondary host plants that often remain edible
later in the season than dwarf plantain. Bay checkerspot adults also
visit flowers for nectar. Nectar plants commonly visited include
Lomatium spp. (desert parsley), Lasthenia californica
(= chrysostoma) (California goldfields), Layia
platyglossa (tidy-tips), Muilla maritima, and others.
Moderate grazing is normally compatible with habitat for the bay
checkerspot, since grazing can reduce the density and height of
nonnative plants that compete with the native plants supporting the
butterfly.
The bay checkerspot's life cycle is closely tied to host plant
biology. Host plants germinate anytime from early October to late
December, and senesce (dry up and die) from early April to mid May.
Most of the active parts of the bay checkerspot life cycle also occur
during this period. Adults emerge from pupae (a transitional stage
between caterpillar and adult butterfly) in early spring, and feed on
nectar, mate, and lay eggs during a flight season that typically lasts
for 4 to 6 weeks in the period between late February to early May. The
eggs hatch and the tiny larvae feed for about 2 to 3 weeks before
entering diapause (a temporary cessation of development) in mid to late
spring. The postdiapause larvae emerge after winter rains stimulate
germination of Plantago, and feed and bask until they are large
enough to pupate and emerge as adults (Service 1998). If insufficient
food is available, a post-diapause checkerspot larva can re-enter
diapause and emerge again one year or more later (Singer and Ehrich
1979; Mattoni et al. 1997).
Most Euphydryas editha subspecies exhibit generally
sedentary behavior, with adults frequently remaining in the same
habitat patch in which they developed as larvae (Ehrlich 1961, 1965;
Boughton 1999, 2000). Female bay checkerspots were found to be more
likely to emigrate than males (Ehrlich et al. 1984). When
female Euphydryas editha butterflies fail to encounter
preferred host plants, the likelihood of emigration to other suitable
habitat patches increases (Thomas and Singer 1987). Adult dispersal by
the bay checkerspot is typically less than 150 meters (490 feet)
between recaptures (Ehrlich 1961, Ehrlich 1965, Gilbert and Singer
1973). However, Harrison (1989) recaptured bay checkerspots greater
than 1 kilometer (0.6 mile) from the point of release in 5 percent of
cases. Long-distance dispersal in bay checkerspot butterflies has been
documented as far as 7.6 km (4.7 miles) (D. Murphy pers. comm.), 5.6 km
(3.5 miles) (1 male), and 3 km (2 miles) (1 female) (Harrison 1989).
The butterflies are likely to be capable of dispersing even longer
distances. In all dispersal observations and experiments, long-distance
movements are hard to detect, and thus their frequency and importance
are difficult to quantify. Qualitative observations suggest that bay
checkerspots move readily over suitable grassland habitat, but are more
reluctant to cross scrub, woodland or other unsuitable habitat. Roads,
especially, those traveled more heavily and at higher speeds, present a
risk of death or injury to dispersing butterflies. Where corridors that
facilitate dispersal exist, they may support the persistence of bay
checkerspot populations.
Long-distance habitat patch colonization may be achieved within a
single season through long-distance dispersal of individual
butterflies, or over several seasons through stepping-stone habitat
patch colonization and dispersal events. In one study of the Santa
Clara County bay checkerspot metapopulation, no colonizations of
unoccupied habitat patches farther than 4.5 kilometers (2.8 miles) from
the source population were detected over a 10-year period (Harrison
et al. 1988). A mathematical model of unknown accuracy
predicted satellite habitat patches at a distance greater than 7 to 8
kilometers (4 to 5 miles) from a primary source population were not
likely to support populations (Harrison et al. 1988).
The known range of the bay checkerspot is now reduced to Santa
Clara and San Mateo counties, and it is patchily distributed in these
locales. Studies of the bay checkerspot have described its distribution
as an example of a metapopulation (see literature cited in Service
1998). A metapopulation is a group of spatially separated populations
that can occasionally exchange dispersing individuals. The populations
in a metapopulation are usually thought of as undergoing interdependent
extinction and colonization, where individual populations may go
extinct, but later recolonize from another population. That is,
although member populations may change in size independently, their
probabilities of existing at a given time are not independent of one
another because they are linked by processes of extinction and mutual
recolonization, processes that occur on the order of every 10 to 100
generations (Harrison et al. 1988). The ability and propensity
of larvae to undergo multiple-year diapause in the field, and survival
rates during repeated diapause, all currently unquantified, will also
affect the persistence time of local populations. Bay checkerspot
populations may also exhibit ``'pseudo-extinction,''' where the species
is not found, but nonetheless continues to inhabit a site and reappears
in a subsequent year. Since the early stages of the bay checkerspot are
extremely difficult or impossible to locate in surveys (White 1987),
the failure to discover caterpillars that diapause for more than 1 year
may be responsible for pseudo-extinctions. Because of pseudo-extinction
and metapopulation dynamics, even sites that in some years apparently
lack the bay checkerspot are important to the survival and recovery of
the species.
The timescale of bay checkerspot metapopulation dynamics, which
includes boom and bust fluctuations of site populations, effects of
California's variable climate, extirpations (loss of local populations)
and recolonizations, is on the scale of decades to centuries, much
longer than typical human planning efforts. Adequacy of designated
critical habitat lands for conservation of the bay checkerspot depends
on long-term persistence of the species' Santa Clara and San Mateo
metapopulations, through conservation of many habitat patches and
opportunity for dispersal/
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recolonization /gene flow events that link populations in the
metapopulations. Such dispersal events must include long-distance
colonizations that are rare because they occur during unusually
favorable years or sequences of years for the bay checkerspot,
resulting in population booms and many more dispersing butterflies.
Bay checkerspot populations vary greatly from year to year. Many or
most individuals of the species live only a single year, and with high
fecundity (fertility), high mortality, and sensitivity to weather and
perhaps other ecological conditions, large population swings are common
for the bay checkerspot. Fluctuations of more than 100-fold have been
observed. These fluctuations are not always in synchrony among
populations at different sites.
Weiss et al. (1988) and Murphy and Rehm (1992) found that
the populations of the bay checkerspot butterfly take refuge during dry
years largely on cool north- and northeast-facing serpentine grassland
slopes. However, they reported that during years of above-average
rainfall the species expands its population on warmer slopes, including
more xeric south- and west-facing slopes. Although infrequent and
short-term, such expansions can contribute to the long-term
metapopulation persistence, especially for a species like the bay
checkerspot, whose numbers are regulated more by environmental factors
than population density. Murphy and White (1984) stated that long-
distance dispersal events associated with population outbreaks may
contribute significantly to colonization or recolonization of
unoccupied areas and hence to long-term survival of the checkerspot
butterflies.
Habitat areas that appear to be low quality or are temporarily low
quality, therefore, can be essential to the long-term persistence of
bay checkerspot populations, which reside in habitats vulnerable to
highly variable or catastrophic environmental phenomena, such as
drought, or habitat destruction caused by urban development. Patches of
habitat, whether of high or marginal quality, can serve as ``stepping
stones'' for regional metapopulations. These patches can facilitate
gene flow between small populations and can provide routes for
individuals to colonize surrounding habitats that have been subject to
local extinction. Loss of temporarily empty ``stepping stone'' habitat
patches would disrupt the dynamics of the entire bay checkerspot
metapopulation. According to Murphy (1990) ``* * * the necessity of
protecting remnants of once extensive metapopulations will demand the
protection of both presently occupied habitat patches and those which
may be presently unoccupied, but which can support the bay checkerspot
under certain climatic conditions.''
Previous Federal Action
On October 21, 1980, we were petitioned by Dr. Bruce O. Wilcox,
Dennis D. Murphy, and Dr. Paul R. Ehrlich to list the bay checkerspot
as an endangered species. We published a Notice of Status Review on
February 13, 1981 (46 FR 12214). Following our status review, we found
that listing the bay checkerspot was warranted but precluded by other
pending listing actions (49 FR 2485). We proposed the bay checkerspot
for listing as endangered with critical habitat on September 11, 1984
(49 FR 35665), and listed the subspecies as threatened on September 18,
1987 (52 FR 35366). At the time of listing, because of difficulty in
resolving the value of specific habitats to the subspecies and
assessing the activities being conducted in those areas, we concluded
that critical habitat was not determinable. We published a Recovery
Plan for Serpentine Soil Species of the San Francisco Bay Area
(Recovery Plan) in September 1998 that includes the bay checkerspot
(Service 1998), as required under section 4(f) of the Endangered
Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.).
On June 30, 1999, the Center for Biological Diversity filed a
complaint against us challenging our critical habitat findings for
seven species, including the bay checkerspot butterfly. On August 30,
2000, the United States District Court for the Northern District of
California (Southwest Center for Biological Diversity v. Bruce Babbitt,
et al., CIV 99-3202 SC) ruled on several of the species
involved, including the bay checkerspot butterfly. The court ordered us
to propose critical habitat within 60 days of the ruling and to
finalize the designation within 120 days of the proposed designation. A
subsequent settlement agreement with the Center for Biological
Diversity extended the date for the final decision to April 20, 2001.
We proposed critical habitat for the bay checkerspot butterfly on
October 16, 2000 (65 FR 61218). The original comment period closed on
December 15, 2000. A notice of availability for the draft economic
analysis and reopening of the public comment period was published in
the Federal Register on February 9, 2001 (66 FR 9683). The
second comment period closed on March 12, 2001.
Critical Habitat
Critical habitat is defined in section 3 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 consideration
or protection; and (ii) specific areas outside the geographic area
occupied by a species at the time it is listed, upon determination that
such areas are essential for the conservation of the species.
``Conservation'' means the use of all methods and procedures that are
necessary to bring an endangered species or a threatened species to the
point at which listing under the Act is no longer necessary.
Critical habitat receives protection under section 7 of the Act
through the prohibition against destruction or adverse modification of
critical habitat with regard to actions carried out, funded, or
authorized by a Federal agency. Section 7 also requires consultation on
Federal actions that are likely to result in the destruction or adverse
modification of critical habitat. In our regulations at 50 CFR 402.02,
we define destruction or adverse modification as ``* * * the direct or
indirect alteration that appreciably diminishes the value of critical
habitat for both the survival and recovery of a listed species.'' Such
alterations include, but are not limited to, alterations adversely
modifying any of those physical or biological features that were the
basis for determining the habitat to be critical.'' Aside from the
added protection that may be provided under section 7, the Act does not
provide other forms of protection to lands designated as critical
habitat. Because consultation under section 7 of the Act does not apply
to activities on private or other non-Federal lands that do not involve
a Federal nexus, critical habitat designation would not afford any
additional protections under the Act against such activities.
To be included in a critical habitat designation, the habitat must
first be ``essential to the conservation of the species.'' Critical
habitat designations identify, to the extent known using the best
scientific and commercial data available, habitat areas that provide
essential life cycle needs of the species (i.e., areas on which are
found the primary constituent elements, as defined at 50 CFR
424.12(b)).
Section 4 requires that we designate critical habitat at the time
of listing and based on what we know at the time of
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the designation. When we designate critical habitat at the time of
listing or under short court-ordered deadlines, we will often not have
sufficient information to identify all areas of critical habitat. We
are required, nevertheless, to make a decision and, thus, must base our
designations on what, at the time of designation, we know to be
critical habitat.
Within the geographic area occupied by the species, we will
designate only areas currently known to be essential. Essential areas
should already have the features and habitat characteristics that are
necessary to sustain the species. We will not speculate about what
areas might be found to be essential if better information became
available, or what areas may become essential over time. If the
information available at the time of designation does not show that an
area provides essential life cycle needs of the species, then the area
should not be included in the critical habitat designation. Within the
geographic area occupied by the species, we will not designate areas
that do not now have the primary constituent elements, as defined at 50
CFR 424.12(b), that provide essential life cycle needs of the species.
Our regulations state that, ``The Secretary shall designate as
critical habitat areas outside the geographic area presently occupied
by the species only when a designation limited to its present range
would be inadequate to ensure the conservation of the species'' (50 CFR
424.12(e)). Accordingly, when the best available scientific and
commercial data do not demonstrate that the conservation needs of the
species require designation of critical habitat outside of occupied
areas, we will not designate critical habitat in areas outside the
geographic area occupied by the species.
Our Policy on Information Standards Under the Endangered Species
Act, published in the Federal Register on July 1, 1994 (Vol.
59, p. 34271), identifies criteria, establishes procedures, and
provides guidance to ensure that decisions made by the Service
represent the best scientific and commercial data available. It
requires Service biologists, to the extent consistent with the Act and
with the use of the best scientific and commercial data available, to
use primary and original sources of information as the basis for
recommendations to designate critical habitat. When determining which
areas are critical habitat, a primary source of information is the
listing package for the species. Additional information may be obtained
from a recovery plan, articles in peer-reviewed journals, conservation
plans developed by States and counties, scientific status surveys and
studies, biological assessments, unpublished materials, and expert
opinion or personal knowledge.
Habitat is often dynamic, and species may move from one area to
another over time. Furthermore, because of the information available
for us at the time of designation, we recognize that designation of
critical habitat may not include all of the habitat areas that may
eventually be determined to be necessary for the recovery of the
species. For these reasons, critical habitat designations do not signal
that habitat outside the designation is unimportant or may not be
required for recovery. Areas outside the critical habitat designation
will continue to be subject to conservation actions that may be
implemented under section 7(a)(1), and to the regulatory protections
afforded by the section 7(a)(2) jeopardy standard and the take
prohibitions of section 9 of the Act, as determined on the basis of the
best available information at the time of the action. We specifically
anticipate that federally funded or assisted projects affecting listed
species outside their designated critical habitat areas may still
result in jeopardy findings in some cases. Similarly, critical habitat
designations made on the basis of the best available information at the
time of designation will not control the direction and substance of
future recovery plans, habitat conservation plans, or other species
conservation planning efforts if new information available to these
planning efforts calls for a different outcome.
Methods
In identifying areas that are essential to conserve the bay
checkerspot, we used the best scientific information available. This
included habitat suitability and site-specific species information. We
have emphasized areas of current and historical bay checkerspot
occurrences, especially larger sites in proximity to known occurrences.
To maintain genetic and demographic interchange that will help maintain
the viability of a regional metapopulation, we included corridor areas
that allow movement between populations. Dispersal is a crucial
function for a species with metapopulation dynamics like the bay
checkerspot.
We used data on known and historic locations and maps of serpentine
soils to identify potentially important areas. Then, through the use of
1990s digital orthophotos available through the Bay Area Digital
GeoResource (BADGER) website (http://badger.parl.com), and limited
ground checking, we estimated the current extent of suitable breeding
habitat. We included in critical habitat both suitable habitat and
areas that link suitable breeding habitat, since these links facilitate
movement of individuals between habitat areas and are important for
dispersal and gene flow and, thus, to the conservation of the
subspecies. For the final rule, we checked the critical habitat
boundaries we proposed for the subspecies against 1999 SPOT satellite
imagery and removed identifiable developed areas.
Our 1984 proposal to list the bay checkerspot with critical habitat
(49 FR 35665) proposed five critical habitat zones. Four of the five
are included in this designation, with modifications based on improved
knowledge of the biology and habitat of the subspecies. Since
publication of the original proposal, the fifth zone (Woodside Zone)
has been mostly converted to housing. Therefore, it is not included in
the critical habitat designation. Since 1984, a great deal of
literature on the bay checkerspot butterfly, both published and
unpublished, has added to our understanding of the subspecies (see
literature cited in Service 1998; Weiss 1999; Weiss and Launer 2000).
Based on this expanded information and other information in the
Recovery Plan (Service 1998), we have been able to identify habitats
and populations that were poorly documented before the mid-1980s, and
assess their significance. Besides the four previously identified
critical habitat zones, this final rule identifies 11 additional
habitat units essential to the conservation of the bay checkerspot, for
a total of 15 critical habitat units. Further, information provided in
comments on the proposed designation and draft economic analysis were
evaluated and taken into consideration in the development of this final
designation.
Primary Constituent Elements
In accordance with section 3(5)(A)(i) of the Act and regulations at
50 CFR 424.12(b), in determining which areas to designate as critical
habitat, we must consider those physical and biological features
(primary constituent elements) essential to the conservation of the
species and that may require special management considerations and
protection. These include, but are not limited to, space for individual
and population growth and for normal behavior; food, water, or other
nutritional or physiological requirements; cover or shelter; sites for
breeding, reproduction, or rearing of
[[Page 21454]]
offspring; and habitats that are protected from disturbance or are
representative of the historic geographical and ecological
distributions of a species.
The primary constituent elements of critical habitat for the bay
checkerspot are those habitat components that are essential for the
primary biological needs of foraging, sheltering, breeding, maturation,
and dispersal. The areas we are designating as critical habitat provide
some or all of the known primary constituent elements for the
subspecies, which include: stands of Plantago erecta,
Castilleja exserta, or Castilleja densiflora; spring
flowers providing nectar; pollinators of the bay checkerspot's food and
nectar plants; soils derived from serpentinic rock; and space for
dispersal between habitable areas. In addition, the following are each
primary constituent elements to be conserved when present in
combination with one or more of the primary constituent elements above:
areas of open grassland, topography with varied slopes and aspects
providing surface conditions with warm and moderate to cool
temperatures during sunny spring days, stable holes or cracks in the
soil and surface rocks or rock outcrops, wetlands providing moisture
during times of spring drought.
Appropriate grassland vegetation provides cover for larvae, pupae
and adults, egg-laying stimuli and sites for females, and adequate open
ground for larvae to be able to crawl efficiently in search of
foraging, basking, diapause, or pupation sites (Service 1998). Stands
of food plants, including nectar plants, are important in the bay
checkerspot's life cycle. The bay checkerspot's primary larval food
plant is Plantago erecta, an annual, native plantain. The
larvae also often use a secondary food plant species, usually either
Castilleja (Orthocarpus) densiflora (purple owl's-clover) or
Castilleja exserta (Orthocarpus purpurascens) (exserted
paintbrush). These secondary food plants tend to remain edible later in
the season than the plantain. Bay checkerspot adults benefit from
visiting flowers for nectar. Nectar plants commonly visited include
Lomatium spp. (desertparsley), Lasthenia californica (=
chrysostoma) (California goldfields), Layia platyglossa (tidy-
tips), Muilla maritima (sea muilla), and others.
Adequate native pollinators to sustain populations of
Castilleja and nectar species, including, but not limited to,
such groups as bumblebees and solitary bees, are important to the value
of critical habitat because these plants are dependent on pollinators
to reproduce and perpetuate their populations in the area. Plantago
erecta is thought to be self-pollinating.
The bay checkerspot usually is found associated with grasslands on
serpentine soils, such as the Montara soil series. In Santa Clara
County, the Inks and Climara soil series are related soils and often
have inclusions of Montara (U.S. Soil Conservation Service 1974).
Henneke and other serpentine soils also occur within the range of the
bay checkerspot. Serpentine soils often support other primary
constituent elements, but they are not limited to serpentine soils.
Soil structure with stable holes or cracks and surface rocks or rock
outcrops provide cover and shelter for bay checkerspot larvae seeking
diapause sites and basking sites.
Bay checkerspot adults have been observed to fly considerable
distances during drought conditions to draw water or solutes from moist
soils around wetlands (``puddling,'' Launer et al. 1993).
Triggering of the puddling behavior by drought conditions suggests it
is a directed, adaptive behavior, and that the butterflies are seeking
out moist areas during times of water or heat stress to obtain
essential nutrients or water (Launer et al. 1993).
Adult bay checkerspots are capable of dispersing over long
distances. Movements of more than 5.6 kilometers (km) (3.5 miles (mi))
have been documented (see Service 1998), and longer movements are
possible. Adult dispersal, especially by fertilized females carrying
eggs, is vital to the maintenance of natural bay checkerspot
metapopulation structure, which requires reestablishment or
replenishment of populations that are at or near local extinction.
Roads, especially those traveled more heavily and at higher speeds,
present a risk of death or injury to dispersing bay checkerspots. Where
open spaces exist that facilitate dispersal, they support the
persistence of bay checkerspot populations and metapopulations. Some
habitats or land uses are thought to be more suitable for dispersal
than others; for example, grassland may be more readily crossed than
woodland or landscaped areas. But documented long-distance movements
demonstrate that the bay checkerspot is sometimes capable of crossing a
variety of substrates (Service 1998).
Topographic diversity provides opportunities for early season
warmth as well as cool north-and east-facing slopes that are a refuge
for the subspecies during droughts. Bay checkerspot larvae develop more
rapidly when they can bask in sunlight that penetrates short-statured
grassland vegetation. Adults also use warm exposures for basking, and
find early-season nectar plants on warm south-and west-facing slopes
(Weiss et al. 1988).
Criteria Used To Identify Critical Habitat
In an effort to map areas that have the features essential to the
conservation of the subspecies, we used data on known bay checkerspot
locations, and conservation planning areas that were identified in the
Recovery Plan (Service 1998) as essential for the recovery of the
subspecies.
We also considered the existing status of lands in designating
areas as critical habitat. The bay checkerspot is known to occur on
State, county, and private lands. The range of critical habitat extends
in the south from the San Martin area, in Santa Clara County, north to
San Bruno Mountain in San Mateo County. We could not depend on Federal
lands for critical habitat designation because we are not currently
aware of any Federal lands within the range of the bay checkerspot that
can be inhabited by the butterfly. We are also not aware of any Tribal
lands in or near the critical habitat units for the bay checkerspot.
Section 10(a) of the Act authorizes us to issue permits to take
listed species incidental to otherwise lawful activities. An incidental
take permit application must be supported by a habitat conservation
plan (HCP) that identifies conservation measures that the permittee
agrees to implement for the species to minimize and mitigate the
impacts of the requested incidental take. One small, short-term HCP
covers the bay checkerspot on about 4 hectares (ha) (10 acres (ac)) of
critical habitat through November 2001. This HCP permits temporary
project-related impacts from electric transmission line work. To date,
project construction anticipated to affect the bay checkerspot is
substantially complete (see the Relationship to Habitat Conservation
Plans section below for additional information on the relationship
between HCPs and critical habitat designation).
In selecting areas of critical habitat, we made an effort to avoid
developed areas, such as towns and other similar lands, that are
unlikely to contribute to bay checkerspot conservation. However, the
information available to us did not allow us to exclude all recently
developed areas, such as towns, housing developments, or other lands
unlikely to contain the primary constituent elements essential for
conservation of the bay checkerspot. Existing features and structures
within the boundaries of the mapped units, such as buildings, roads,
aqueducts, railroads, airports,
[[Page 21455]]
other paved areas, lawns, and other urban landscaped areas are not
likely to contain primary constituent elements essential for the
conservation of the bay checkerspot. Federal actions limited to those
areas, therefore, would not trigger a section 7 consultation, unless
they affect the species and/or primary constituent elements in adjacent
critical habitat.
Critical Habitat Designation
The areas we are designating as critical habitat currently provide
some or all of those habitat components necessary to meet the primary
biological needs of the bay checkerspot butterfly. Table 1 shows the
approximate area of critical habitat by county and land ownership.
Lands designated are under private and State and local ownership. The
subspecies is not known to occur, or to have historically occurred, on
Federal lands. Lands designated as critical habitat have been divided
into 15 Critical Habitat Units. Critical habitat designated for the bay
checkerspot includes 9,673 ha (23,903 ac), with 806 ha (1,992 ac) in
San Mateo County and 8,867 ha (21,911 ac) in Santa Clara County.
Because the bay checkerspot is nearly confined to island-like patches
of habitat, its critical habitat is easily categorized into separate
areas or units (see maps). We present brief descriptions of each unit,
and our reasons for designating it as critical habitat, below.
Conserving the bay checkerspot includes the need to reestablish
historic populations of the subspecies to areas within several of the
units, in order to secure the butterfly in representative sites in its
former range, and in a range of habitat and climate conditions.
Returning the bay checkerspot to good representatives of its former
diversity of sites and habitat and climate conditions is necessary to
reduce the long-term risk of range-wide extinction of the subspecies
(Service 1998).
The long-term probability of the survival and recovery of the bay
checkerspot butterfly is dependent on the maintenance of its
metapopulation dynamics through the protection of existing serpentine
habitat, the movement of individuals between these sites, and the
ability of the butterflies to recolonize habitat where they have become
extirpated. Recolonization of sites with suitable habitat that
contained populations that have become extinct and the maintenance of
genetic diversity within existing populations is dependent upon
``stepping stones'' of habitat, including habitat that may appear
marginal, that the bay checkerspot can colonize and disperse from
during rare periods of very favorable climatic conditions.
Table 1.--Approximate Critical Habitat in Hectares (ha) and Acres (ac) by County and Ownership
[Area estimates reflect critical habitat unit boundaries; however, not all the areas within those broad boundaries, such as cities, towns, or other
developments, contain habitat features considered essential to the survival of the bay checkerspot]
--------------------------------------------------------------------------------------------------------------------------------------------------------
County Federal Local/State Private Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
San Mateo....................... 0 520 ha (1,285 ac)................. 286 ha (707 ac)................... 806 ha (1,992 ac).
Santa Clara..................... 0 922 ha (2,278 ac)................. 7,945 ha (19,633 ac).............. 8,867 ha (21,911 ac).
-----------------------------------------------------------------------------------------------------------------------
Total........................... 0 1,442 ha (3,563 ac)............... 8,231 ha (20,340 ac).............. 9,673 ha (23,903 ac).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit 1. Edgewood Park/Triangle Unit
Occurring in San Mateo County, this unit comprises 217 ha (535 ac)
in T.5 S., R.4 W. (Mount Diablo meridian/base line). Included is most
of Edgewood Natural Preserve, a county park southeast of the junction
of Edgewood Road, and I-280, and watershed lands of the San Francisco
Public Utilities Commission, Water Supply and Treatment Division,
within the triangle formed by I-280, Edgewood Road, and Canada Road, as
well as a small additional area of serpentine soil on the west side of
Canada Road. Much of this area also falls within the San Francisco
State Fish and Game Refuge. The area supports the Edgewood population
of the bay checkerspot discussed in the subspecies' Recovery Plan,
which is the main population of the San Mateo metapopulation of the bay
checkerspot (Service 1998). Without the Edgewood population the San
Mateo metapopulation would almost certainly go extinct, resulting in
the loss of one of only two metapopulations of the bay checkerspot and
a significant range reduction for the subspecies. This population is
also the northernmost remaining population of the subspecies. The unit
contains considerable areas of good habitat, although additional
management attention may be needed for the bay checkerspot to thrive
here. The unit is 7 km (4 mi) northwest of the Jasper Ridge unit.
Unit 2. Jasper Ridge Unit
Occurring within San Mateo County, the unit covers 287 ha (709 ac)
in Stanford University's Jasper Ridge Biological Preserve, in T.6 S.,
R.3 W. (Mount Diablo meridian/base line). Decades of data and dozens of
published scientific papers about the Jasper Ridge population of the
bay checkerspot exist. The population has severely declined in recent
years, and may now be extirpated (Service 1998). However, we are
confident that a stable population of the subspecies can be restored to
Jasper Ridge because the area is protected and managed as a biological
preserve by Stanford University and suitable habitat continues to be
present. The Jasper Ridge population is essential as a supporting
element of the San Mateo metapopulation, and a backup to the Edgewood
and prospective San Bruno Mountain populations. The unit is 34 km (21
mi) west-northwest of the Communications Hill unit, the closest
connection to units in the Santa Clara County metapopulation.
Unit 3. San Bruno Mountain Unit
This unit also occurs in San Mateo County, with approximately 303
ha (748 ac) in T.3 S., R.5 W. (Mount Diablo meridian/base line), above
the 152 m (500 ft) elevation contour, and east of the western Pacific
Gas and Electric transmission corridor on San Bruno Mountain. This unit
is mostly within San Bruno Mountain State and County Park, and is
inside the boundaries of the San Bruno Mountain Area Habitat
Conservation Plan area. The bay checkerspot formerly inhabited this
area, but is believed to have been extirpated around 1986 by a
combination of factors, including over-collection and a fire that
burned its habitat. However, this unit has supported a substantial bay
checkerspot population in the past, and it is reasonable to expect that
the butterfly can be reestablished here.
San Bruno Mountain represents the most northerly part of the
subspecies' former range on the San Francisco peninsula with reasonably
good conditions to support the bay checkerspot. The San Bruno Mountain
[[Page 21456]]
unit is essential as a supporting element of the San Mateo
metapopulation, and a backup to the Edgewood and Jasper Ridge
populations. The unit lies 25 km (16 mi) north-northwest of the
Edgewood Park/Triangle unit.
Unit 4. Bear Ranch Unit
The Bear Ranch unit, totaling 250 ha (617 ac), lies west of Coyote
Lake (Coyote Reservoir) in the eastern hills of the Santa Clara Valley,
in southern Santa Clara County (T.9 S., R.4 E. and T.10 S., R.4 E.,
Mount Diablo meridian/base line). The unit is named for a ranching
property that partly occurs in the unit. The ranch and lands, including
and surrounding the unit, are now owned and managed by the Santa Clara
County Parks and Recreation Department. This location represents one of
the most recent population discoveries of the bay checkerspot, and has
been documented for several years as a persistent population. The
population is also one of the most southerly occurrences of the bay
checkerspot. It lies about 10 km (6 mi) southeast of the Kirby core
population area described in the Recovery Plan (Service 1998), with
some intervening habitable areas and adequate dispersal corridors. Over
40 ha (100 ac) of mapped and an unquantified acreage of unmapped
serpentine soils in several large to small patches occur within the
unit. In addition to the significance of its position establishing the
outer perimeter of the range of the subspecies, the Recovery Plan makes
the protection of large, good-quality habitat areas near core
populations, such as this, a high priority (Service 1998).
Unit 5. San Martin Unit
This unit includes 237 ha (586 ac) west of San Martin, in the
western foothills of the Santa Clara Valley in southern Santa Clara
County (T.9 S., R.3 E). Included in the designated critical habitat are
extensive areas of serpentine soils and intervening areas that support
habitat or are used for dispersal. Regular occupation of the unit by
the bay checkerspot has been documented, although no quantitative
surveys are available of this population. The unit lies entirely on
private lands in unincorporated Santa Clara County, about 6.4 km (4 mi)
west-southwest of the Bear Ranch unit and 11 km (7 mi) south of the
Kirby core area. This is the second population at the southern
periphery of the range. The Recovery Plan makes the protection of
large, good-quality habitat areas near core populations, such as this,
a high priority (Service 1998). We are not aware of any public lands in
the unit.
Unit 6. Communications Hill Unit
Communications Hill, and adjacent hilltops in south-central San
Jose, are formed by outcroppings of serpentine rock, with grasslands
capable of supporting the bay checkerspot. This unit occurs in Santa
Clara County and covers 179 ha (443 ac) of mostly undeveloped land. It
also crosses a major road and railroad tracks, and includes a quarry
that we believe, after appropriate reclamation, could be restored to
bay checkerspot habitat. The bay checkerspot has been documented on
Communications Hill in the past. A survey of a limited portion of the
hill conducted in the spring of 2000, but which missed the early weeks
of the butterflies' flight season, did not detect the subspecies
(Arnold 2000). Whether the unit is currently occupied is not known. We
believe this unit functions as habitat of the species, functions in its
regional metapopulations dynamics, and functions as a ``stepping
stone'' for bay checkerspot dispersal. The Recovery Plan (Service 1998)
calls for conservation of larger habitat areas currently or
historically occupied by the bay checkerspot. Conservation of habitat
at Communications Hill is identified in the Recovery Plan as a priority
2 action, i.e., a recovery action that must be taken to prevent decline
or other negative impact short of extinction (Table IV-1, task 2.1.19
in the Recovery Plan). This location also represents the northwestern-
most remnant of the Santa Clara County metapopulation. The unit is
surrounded by Curtner Avenue, Almaden Expressway, Hillsdale Avenue, and
Monterey Road (T.7 S., R.1 E., Mount Diablo meridian/base line), and
lies 3 km (2 mi) west of the Silver Creek unit.
Much of this unit lies on private lands within unincorporated
lands, with a smaller area in the City of San Jose. Portions of a Santa
Clara County communications facility, a San Jose water company
facility, and recently developed lands may fall within the unit. Only
currently undeveloped areas supporting the primary constituent elements
of habitat for the bay checkerspot would be subject to regulatory
oversight of any Federal actions.
Unit 7. Kalana Hills Unit
The Kalana Hills unit in Santa Clara County comprises 99 ha (244
ac) on the southwest side of the Santa Clara Valley between Laguna
Avenue and San Bruno Avenue (T.9 S., R.2 E, Mount Diablo meridian/base
line). Four serpentine outcrops form hills or hillsides in this area.
At least one population of the bay checkerspot has been documented on
one or all of these outcrops in recent surveys. This unit also includes
some intervening areas that connect the closer outcrops. The Coyote
Ridge unit lies about 3.2 km (2 mi) to the northeast, the Santa Teresa
unit about 2 km (1.2 mi) to the northwest, the San Vicente-Calero unit
about 3.2 km (2 mi) to the west, and the Morgan Hill unit about 3.2 km
(2 mi) to the southeast. Because of its proximity to several other,
large population centers for the bay checkerspot, we expect the Kalana
Hills unit to be regularly occupied by the subspecies. If, as is
possible given the bay checkerspot's large population swings, the
butterfly's population in the unit were to die out, it is likely to be
quickly reestablished by bay checkerspots immigrating from adjacent
sites. We are not aware of any public lands in the unit. A portion of
the largest and northernmost serpentine outcrop is within the limits of
the City of San Jose; the remainder of the unit is on private lands in
unincorporated Santa Clara County.
Unit 8. Kirby Unit
The Kirby critical habitat unit includes 2,797 ha (6,912 ac) along
the southern portion of ``Coyote Ridge'' in Santa Clara County (T.8 S.,
R.2 E., T.8 S., R.3 E., and T.9 S., R.3 E., Mount Diablo meridian/base
line). It contains the Kirby area for the bay checkerspot discussed in
the subspecies' Recovery Plan (Service 1998). The ridge, informally
known as Coyote Ridge, runs northwest to southeast, parallel to and
east of Highway 101 from Yerba Buena Road to Anderson Reservoir in
Santa Clara County, and forms the eastern slope of the Santa Clara
Valley (U.S. Geological Survey (USGS) 7.5 minute quadrangles San Jose
East, Lick Observatory, Santa Teresa Hills, and Morgan Hill. The ridge
is not named on these maps). Coyote Ridge also parallels the Silver
Creek Fault and Silver Creek itself. Extensive serpentine soil areas,
and four population areas for the bay checkerspot (Kirby, Metcalf, San
Felipe, and Silver Creek Hills) lie on, or adjacent to, this ridge and
fault system (Service 1998). Metcalf Canyon, Silver Creek, and
nonserpentine soil areas create natural divisions among these four
population areas. The Kirby unit is the southernmost of four critical
habitat units corresponding to the four population areas along Coyote
Ridge, and runs along this ridge east of Highway 101 and Coyote Creek
from Metcalf Canyon south to Anderson Lake. The northern boundary of
the Kirby unit abuts the Metcalf unit. The northwest tip of the Kirby
unit also
[[Page 21457]]
connects to the Tulare Hill Corridor unit.
The Kirby critical habitat unit regularly supports one of the
largest populations of the bay checkerspot, and is considered one of
the centers of the subspecies' Santa Clara County metapopulation. The
Recovery Plan (Service 1998) considers protection of the area of the
highest priority for conservation of the subspecies. The unit contains
several hundred acres of diverse serpentine grassland habitat as well
as nectaring areas, seasonal wetlands, and dispersal areas. The unit
includes lands within the limits of the City of San Jose, private lands
in unincorporated Santa Clara County, and small areas in the City of
Morgan Hill. Public lands in this unit include the Santa Clara County
Field Sports Park and portions of Santa Clara County Motorcycle Park,
Anderson Lake County Park, Coyote Creek Park, and lands of the Santa
Clara Valley Water District. A 101 ha (250 ac) reserve, leased by Waste
Management Inc. on behalf of the Kirby Conservation Trust to further
conservation of the bay checkerspot, also falls within the unit. The
Kirby Conservation Trust has funded extensive research on the bay
checkerspot for more than a decade at the lease site, greatly improving
our understanding of the ecology, population dynamics, and conservation
needs of the subspecies (see literature cited in Service 1998). We
removed approximately 57 ha (141 ac), all nonserpentine lands, from the
unit as it was proposed on October 16, 2000.
Unit 9. Morgan Hill Unit
The Morgan Hill unit in Santa Clara County includes 293 ha (724 ac)
northwest of the City of Morgan Hill in Santa Clara County (T.9 S., R.2
E., T.9 S., R.3 E., Mount Diablo meridian/base line). It lies less than
3.2 km (2 mi) southwest of the Coyote Ridge unit and about 3.2 km (2
mi) southeast of the Kalana Hills unit. This is the area described as
``north of Llagas Avenue'' in our 1998 Recovery Plan. The unit is
partly within the limits of the City of Morgan Hill and partly on
private lands in unincorporated Santa Clara County. Murphy Springs
Park, a small city park, is within the unit. The Morgan Hill unit has
large areas of serpentine soils and grassland with a variety of slope
exposures, suitable for the bay checkerspot. The unit has been
documented to be occupied by the bay checkerspot in the past, as well
as in more recent surveys in the past 2 to 3 years. Because of its
large habitat area and proximity to core populations of the bay
checkerspot, the Recovery Plan considers protection of this area
essential to the conservation of the subspecies (Service 1998). We
removed approximately 81 ha (201 ac), mostly residential development,
from the unit as it was proposed.
Unit 10. Metcalf Unit
This unit includes 1,356 ha (3,351 ac) in Santa Clara County, east
of Highway 101, south of Silver Creek Valley Road, north of Metcalf
Canyon, and west of Silver Creek (T.8 S., R.2 E., Mount Diablo
meridian/base line). The unit contains the Metcalf area for the bay
checkerspot, one of the four largest habitat areas and three largest
current population centers for the bay checkerspot (Service 1998). As
of the spring of 2000, this area supported the bay checkerspot's
densest population (Weiss in litt. 2000). Hundreds of acres of
serpentine soils, and thousands of bay checkerspot butterflies, occur
within the unit. This area is considered one of the centers of the
subspecies' Santa Clara County metapopulation. The Recovery Plan
(Service 1998) considers protection of the area of the highest priority
for conservation of the bay checkerspot. This unit adjoins the Kirby
unit to the south, San Felipe unit to the east, Silver Creek Hills unit
to the north, and Tulare Hill Corridor unit to the west, and provides
crucial habitat connectivity for bay checkerspot dispersal among these
areas. The Metcalf unit lies in the City of San Jose and on private
lands in unincorporated Santa Clara County. Portions of Santa Clara
County Motorcycle Park, Coyote Creek Park, and lands of Santa Clara
Valley Water District fall within the unit. We removed approximately
260 ha (643 ac), mostly commercial and residential development, from
the unit as it was proposed.
Unit 11. San Felipe Unit
This unit includes 404 ha (998 ac) in Santa Clara County, southwest
of San Felipe Road and north of Metcalf Road (T.8 S., R.2 E., Mount
Diablo meridian/base line), primarily on private lands in
unincorporated county lands, but also within San Jose city limits. The
unit contains the San Felipe population area for the bay checkerspot,
one of the four largest habitat areas and three largest current
population centers for the bay checkerspot (Service 1998). This area is
considered one of the centers of the subspecies' Santa Clara County
metapopulation. The Recovery Plan (Service 1998) considers protection
of the area of the highest priority for conservation of the bay
checkerspot. Several hundred acres of serpentine soils occur within the
unit with nectaring and dispersal areas. We are not aware of any public
lands in the unit.
Unit 12. Silver Creek Unit
The Silver Creek unit comprises 318 ha (787 ac), primarily within
the limits of the City of San Jose, but with some area on private lands
in unincorporated Santa Clara County (T.7 S., R.1 E., T.7 S., R.2 E.,
T.8 S., R.2 E., Mount Diablo meridian/base line). This unit is
surrounded by Highway 101 and Coyote Creek on the west, Yerba Buena
Road on the north, Silver Creek on the east and northeast, and Silver
Creek Valley Road on the south. The unit includes the Silver Creek
Hills population area for the bay checkerspot (Service 1998). It
includes nearly 405 ha (1,000 ac) of contiguous serpentine soils, other
scattered serpentine outcrops, and also habitat less suitable for
breeding but needed for nectar-feeding or dispersal. Approximately 382
ha (943 ac) of developed areas and graded lands permitted for
development have been removed from the unit as it was proposed.
Included in our final designation for this unit is a roughly 162 ha
(400 ac) nature preserve owned by William Lyon Homes (former Presley
Homes) and managed by the non-profit Silver Creek Preserve. Several
electric transmission lines and two major natural gas lines cross the
unit.
In the last several years, a small population of the bay
checkerspot has been documented in the Silver Creek unit, and the area
has a long history of much larger populations. Portions of the unit
known to have been inhabited by the bay checkerspot in the past are
currently in degraded condition. With the management being implemented
by Lyon Homes and Silver Creek Preserve, we believe that the Silver
Creek Hills population is likely to increase, and that much of the
degraded area will be restored to useful breeding habitat. The Silver
Creek unit has extensive, diverse, and high-quality habitat, and
represents the northernmost unit of the Santa Clara County
metapopulation. The Silver Creek unit provides a population reservoir
critical to the survival of the Santa Clara County metapopulation of
bay checkerspot--the larger and more viable of the two remaining
metapopulations (Service 1998).
Unit 13. San Vicente-Calero Unit
The San Vicente-Calero unit contains 759 ha (1,875 ac) within and
to the west of Calero County Park, Santa Clara County (T.8 S., R.1 E.,
T.8 S., R.2 E., T.9 S., R.1 E., and T.9 S., R.2 E., Mount Diablo
meridian/base line). This area supports a known population of the bay
[[Page 21458]]
checkerspot in a large area of good-quality habitat; other areas within
the unit that are suitable for the bay checkerspot have not been
surveyed. The unit is also within bay checkerspot dispersal distance of
the Santa Teresa Hills unit (see below), which we consider to be
capable of supporting a very large population of the bay checkerspot,
and the Kalana Hills unit (number 9, above), which are themselves
accessible to and from other units. Therefore, we believe the San
Vicente-Calero population can contribute significantly to maintaining
the Santa Clara County metapopulation of the bay checkerspot. For all
these reasons, the Recovery Plan (Service 1998) considers protection of
this area essential to the conservation of the subspecies. The unit is
south of McKean Road and east of the town of New Almaden, Almaden Road,
and Alamitos Creek. It lies about 1.6 km (1 mi) south of the Santa
Teresa unit and about 3.2 km (2 mi) west of the Kalana Hills unit.
Portions of the unit outside the county park are within the limits of
the City of San Jose.
Unit 14. Santa Teresa Hills Unit
The Santa Teresa Hills unit includes 1,821 ha (4,500 ac) in Santa
Clara County (T.8 S., R.1 E. and T.8 S., R.2 E., Mount Diablo meridian/
base line) with extensive areas of serpentine soils. Portions of the
Santa Teresa Hills are known to support the bay checkerspot now, and
have supported the subspecies in the past, but no current comprehensive
survey of the bay checkerspot in the area is available. We believe that
the Santa Teresa Hills could support a significant population of bay
checkerspots. In addition to adding a fifth substantial population to
the Santa Clara County metapopulation, conservation and management of
the Santa Teresa Hills population would support development of a strong
population of the bay checkerspot in a slightly cooler, moister area of
the county, at a site that may experience less air pollution than the
more eastern units. The Santa Teresa Hills critical habitat unit is
intended to include most undeveloped habitat in the area, as well as
intervening areas that are unsurveyed or less suitable but needed for
dispersal among higher-quality areas. The unit lies north of Bailey
Avenue, McKean Road, and Almaden Road, south of developed areas of the
city of Santa Clara, and west of Santa Teresa Boulevard. The unit abuts
the Tulare Hill Corridor unit.
Unit 15. Tulare Hill Corridor Unit
The Tulare Hill Corridor unit, 355 ha (876 ac) in Santa Clara
County, connects the Coyote Ridge (Kirby and Metcalf, and through them,
San Felipe and Silver Creek) and Santa Teresa units. Tulare Hill is a
prominent serpentine hill that rises from the middle of the Santa Clara
Valley in southern San Jose, west of the crossing of Metcalf Road and
Highway 101 (T.8 S., R.2 E., Mount Diablo meridian/base line).
Extensive habitat on the hill is currently occupied by the bay
checkerspot, and is essential both as a population center and for
dispersal across the valley. The Metcalf and Kirby populations of the
bay checkerspot lie less than 1 km (0.6 mi) to the northeast, separated
by a major highway (U.S. 101) and a narrow band of other unfavorable
uses (another large road, railroad tracks, an electrical substation, a
large open reservoir with artificially hardened banks, and agricultural
area). The Santa Teresa Hills population area for the subspecies lies
about 2 km (1.2 mi) to the southwest, with dispersal habitat in
between. We believe the long-term viability of the bay checkerspot
depends on the presence of a corridor for dispersal of adults to and
from the Santa Teresa Hills and Coyote Ridge (Service 1998). Tulare
Hill is an ideal location for such a corridor because of the narrowness
of the valley at this location and the limited amount of development
currently present, the presence of high elevations on the hill that may
attract butterflies over busy roads and developed areas, and the
presence of suitable habitat on Tulare Hill itself. Migrant butterflies
from either Santa Teresa Hills or Coyote Ridge may settle on Tulare
Hill, contributing individuals and genetic diversity to the population
there, and adults from Tulare Hill may migrate to the adjacent habitat
areas.
Public lands within the designated unit include parts of Coyote
Creek Park, Metcalf Park, and Santa Teresa County Park. Roughly half of
Tulare Hill itself is within the limits of the City of San Jose, the
remainder on private lands in unincorporated Santa Clara County.
Several major electrical transmission lines cross the unit. Some areas
within the unit are not inhabited by bay checkerspot individuals but
can function as dispersal corridors.
Effect of Critical Habitat Designation
Section 7 Consultation
Section 7(a)(2) of the Act requires Federal agencies, including the
Service, to ensure that actions they fund, authorize, or carry out do
not destroy or adversely modify critical habitat to the extent that the
action appreciably diminishes the value of the critical habitat for the
survival and recovery of the species. Individuals, organizations,
States, local governments, and other non-Federal entities are affected
by the designation of critical habitat only if their actions occur on
Federal lands, require a Federal permit, license, or other
authorization, or involve Federal funding.
Section 7(a) of the Act requires Federal agencies, including the
Service, 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 proposed or designated. Regulations
implementing this interagency cooperation provision of the Act are
codified at 50 CFR part 402. Section 7(a)(4) and regulations at 50 CFR
402.10 requires Federal agencies to confer with us on any action that
is likely to jeopardize the continued existence of a proposed species
or result in destruction or adverse modification of proposed critical
habitat. Conference reports provide conservation recommendations to
assist the agency in eliminating conflicts that may be caused by the
proposed action. The conservation recommendations in a conference
report are advisory. If a species is listed or critical habitat is
designated, section 7(a)(2) 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 critical habitat. If a Federal action may affect a
listed species or its critical habitat, the responsible Federal agency
(action agency) must enter into consultation with us. Through this
consultation, we would ensure that the permitted actions do not destroy
or adversely modify critical habitat.
When we issue a biological opinion concluding that a project is
likely to result in the destruction or adverse modification of critical
habitat, we also seek to provide reasonable and prudent alternatives to
the project, if any are identifiable. ``Reasonable and prudent
alternatives'' are defined at 50 CFR 402.02 as alternative actions
identified during consultation that can be implemented in a manner
consistent with the intended purpose of the action, that are consistent
with the scope of the Federal agency's legal authority and
jurisdiction, that are economically and technologically feasible, and
that the Director believes would avoid destruction or adverse
modification of critical habitat. Reasonable and prudent alternatives
can vary from slight project modifications to extensive redesign or
[[Page 21459]]
relocation of the project. Costs associated with implementing a
reasonable and prudent alternative are similarly variable.
Regulations at 50 CFR 402.16 require Federal agencies to reinitiate
consultation on previously reviewed actions in instances where critical
habitat is subsequently designated, and the Federal agency has retained
discretionary involvement or control over the action or such
discretionary involvement or control is authorized by law.
Consequently, some Federal agencies may request reinitiation of
consultation or conference with us on actions for which formal
consultation has been completed, if those actions may affect designated
critical habitat, or adversely modify or destroy proposed critical
habitat. Conference reports assist the agency in eliminating conflicts
that may be caused by the proposed action, and may include
recommendations on actions to eliminate conflicts with or adverse
modifications to proposed critical habitat. The conservation
recommendations in a conference report are advisory.
We may issue a formal conference report if requested by a Federal
agency. Formal conference reports on proposed critical habitat contain
an opinion that is prepared according to 50 CFR 402.14, as if critical
habitat were designated. We may adopt the formal conference report as
the biological opinion when the critical habitat is designated, if no
substantial new information or changes in the action alter the content
of the opinion (see 50 CFR 402.10(d)).
Activities on Federal lands that may affect the bay checkerspot or
its critical habitat will require section 7 consultation. Activities on
private or State lands requiring a permit from a Federal agency, such
as a permit from the U.S. Army Corps of Engineers (Corps) under section
404 of the Clean Water Act, a section 10(a)(1)(B) permit from the
Service, or some other Federal action, including funding (e.g.,
Federal Highway Administration (FHA), Federal Aviation
Administration, or Federal Emergency Management Agency (FEMA)), will
also continue to be subject to the section 7 consultation process.
Federal actions not affecting listed species or critical habitat and
actions on non-Federal lands that are not federally funded, authorized,
or permitted do not require section 7 consultation.
Section 4(b)(8) of the Act requires us to briefly evaluate and
describe in any proposed or final regulation that designates critical
habitat those activities involving a Federal action that may destroy or
adversely modify such habitat, or that may be affected by such
designation. Activities that may destroy or adversely modify critical
habitat include those that appreciably reduce the value of critical
habitat for both the survival and recovery of the bay checkerspot.
Within critical habitat, this pertains only to those areas containing
the primary constituent elements. We note that such activities may also
jeopardize the continued existence of the species.
To properly portray the effects of critical habitat designation, we
must first compare the section 7 requirements for actions that may
affect critical habitat with the requirements for actions that may
affect a listed species. Section 7 prohibits actions funded,
authorized, or carried out by Federal agencies from jeopardizing the
continued existence of a listed species or destroying or adversely
modifying the listed species' critical habitat. Actions likely to
``jeopardize the continued existence'' of a species are those that
would appreciably reduce the likelihood of the species' survival and
recovery. Actions likely to ``destroy or adversely modify'' critical
habitat are those that would appreciably reduce the value of critical
habitat for the survival and recovery of the listed species.
Common to both definitions is an appreciable detrimental effect on
both survival and recovery of a listed species. Given the similarity of
these definitions, actions likely to destroy or adversely modify
critical habitat would almost always result in jeopardy to the species
concerned, particularly when the area of the proposed action is
occupied by the species concerned. Designation of critical habitat in
areas occupied by the bay checkerspot is not likely to result in a
regulatory burden above that already in place due to the presence of
the listed subspecies.
Activities that, when carried out, funded, or authorized by a
Federal agency, may affect critical habitat and require that a section
7 consultation be conducted include, but are not limited to:
(1) Ground disturbance, including but not limited to, grading,
discing, ripping and tilling;
(2) Removing, destroying, or altering vegetation (e.g.,
altering grazing practices or seeding);
(3) Water contracts, transfers, diversion, impoundment,
application, or conveyance, groundwater pumping, irrigation, or other
activity that wets or inundates habitat, creates barriers or deterrents
to dispersal, or results in critical habitat being converted to lower
values for the bay checkerspot (e.g., conversion to urban
development, vineyards, landscaping, etc.);
(4) Sale, exchange, or lease of critical habitat that is likely to
result in the habitat being destroyed or degraded;
(5) Recreational activities that significantly deter the use of
critical habitat by bay checkerspots or alter habitat through
associated maintenance activities (e.g., off-road vehicle
parks, golf courses, trail construction or maintenance);
(6) Construction activities that destroy or degrade critical
habitat (e.g., urban and suburban development, building of
recreational facilities such as off-road vehicle parks and golf
courses, road building, drilling, mining, quarrying and associated
reclamation activities); and
(7) Application or drift onto critical habitat of pesticides,
herbicides, fertilizers, or other chemicals or biological agents.
(8) Deposition or release onto critical habitat of pollutants,
other chemicals or biological agents.
Any of the above activities that appreciably diminish the value of
critical habitat, once established, to the degree that they affect the
survival and recovery of the bay checkerspot may be considered an
adverse modification of critical habitat. We note that such activities
may also jeopardize the continued existence of the subspecies.
If you have questions regarding whether specific activities will
constitute destruction or adverse modification of critical habitat
resulting from a Federal action, contact the Field Supervisor,
Sacramento Fish and Wildlife Office (see ADDRESSES section).
Requests for copies of the regulations on listed wildlife, and
inquiries about prohibitions and permits may be addressed to the U.S.
Fish and Wildlife Service, Branch of Endangered Species, 911 N.E. 11th
Ave, Portland, Oregon 97232 (telephone 503/231-2063; facsimile 503/231-
6243).
Relationship to Habitat Conservation Plans (HCPs)
Section 4(b)(2) of the Act allows us broad discretion to exclude
from critical habitat designation areas where the benefits of exclusion
outweigh the benefits of designation, provided the exclusion will not
result in the extinction of the species. We believe that, in most
instances, the benefits of excluding HCPs from critical habitat
designations will outweigh the benefits of including them.
The benefits of including HCP lands in critical habitat are
normally small. Federally authorized, funded, or permitted activities
in designated
[[Page 21460]]
critical habitat that may affect critical habitat require consultation
under section 7 of the Act. This is the major benefit of designating
lands as critical habitat. Consultation would ensure that adequate
protection is provided to avoid adverse modification of critical
habitat. However, our experience indicates that where HCPs are in
place, this benefit is small or non-existent. Currently approved and
permitted HCPs are designed to ensure the long-term survival of covered
species within the plan area. The lands that we would find essential
for the conservation of the species, and thus be considered for
designation of critical habitat would, where we have approved HCPs and
the species is a covered species under the HCP, normally be protected
in reserves and other conservation lands. HCPs, and their associated
implementation agreements, outline management measures and protections
for conservation lands that are crafted to protect, restore, and
enhance their value as habitat for covered species.
In addition, an HCP application must itself be consulted upon by
the Service. While this consultation will not look specifically at the
issue of adverse modification of critical habitat, it will look at the
very similar concept of jeopardy to the listed species in the plan
area. HCPs, particularly large regional HCPs, address land use within
the plan boundaries; habitat issues within the plan boundaries are
thoroughly addressed in the HCP and the consultation on the HCP. Our
experience is that, under most circumstances, consultations under the
jeopardy standard will reach the same result as consultations under the
adverse modification standard. Additional measures to protect the
habitat from adverse modification are not likely to be required.
Further, HCPs typically provide for greater conservation benefits
to a covered species than section 7 consultations because HCPs assure
the long-term protection and management of a covered species and its
habitat, and funding for such management through the standards found in
the 5-Point Policy for HCPs (64 FR 35242) and the HCP No Surprises
regulation (63 FR 8859). Such assurances are typically not provided by
section 7 consultations which, in contrast to HCPs, often do not commit
the project proponent to long-term special management or protections.
Thus, the lands covered by a consultation typically will not provide
the extensive benefits of an HCP.
The development and implementation of HCPs provide other important
conservation benefits, including the development of biological
information to guide conservation efforts and assist in species
recovery and the creation of innovative solutions to conserve species
while allowing for development. The educational benefits of critical
habitat, including informing the public of areas that are important for
the conservation of the species, are essentially the same as those that
would occur from the public notice and comment procedures required to
establish an HCP, as well as the public participation that occurs in
the development of many regional HCPs. For these reasons, then, we
believe that designation of critical habitat has little benefit in
areas covered by HCPs.
In contrast, the benefits of excluding HCPs from being designated
as critical habitat are more significant. In response to other critical
habitat proposals, we have received comments about the additional
regulatory and economic burden of designating critical habitat. These
include the need for additional consultation with us and the need for
additional surveys and information gathering to complete these
consultations. HCP applicants have also stated that they are concerned
that third parties may challenge HCPs on the basis that they result in
adverse modification or destruction of critical habitat.
The benefits of excluding HCPs from critical habitat include
relieving landowners, communities, and counties of any additional minor
regulatory review that might be imposed by critical habitat. This
benefit is important given our past representations that once an HCP is
negotiated and approved by us after public comment, activities
consistent with the plan will satisfy the requirements of section
10(a)(1)(B) of the Act. Many HCPs, particularly large regional HCPs,
take many years to develop and, upon completion, become regional
conservation plans that are consistent with the recovery of covered
species. Many of these regional plans benefit many species, both listed
and unlisted. Imposing an additional regulatory review after HCP
completion not only results in minor, if any, additional benefit to the
species, it may jeopardize conservation efforts and partnerships in
many areas and could be viewed as a disincentive to those developing
HCPs. Excluding HCPs provides us with an opportunity to streamline
regulatory compliance and confirms regulatory assurances for HCP
participants.
Another benefit of excluding HCPs is that it would encourage the
continued development of partnerships with HCP participants, including
States, local governments, conservation organizations, and private
landowners, that together can implement conservation actions we would
be unable to accomplish alone. By excluding areas covered by HCPs from
critical habitat designation, we preserve these partnerships, and, we
believe, set the stage for more effective conservation actions in the
future.
In general, then, we believe the benefits of critical habitat
designation to be small in areas covered by approved HCPs. We also
believe that the benefits of excluding HCPs from designation are small,
but significant. We believe that the small benefits of inclusion, when
weighed against the benefits of exclusion, including the benefits of
relieving property owners of an additional layer of approvals and
regulation, together with the encouragement of conservation
partnerships, would generally result in HCPs being excluded from
critical habitat designation under section 4(b)(2) of the Act.
Given this general analysis, we expect to analyze the specific
benefits in each particular critical habitat designation because not
all HCPs are alike with regard to species coverage and design. Within
this designation, we need to evaluate completed and legally operative
HCPs in the range of the bay checkerspot to determine whether the
benefits of excluding these particular areas outweigh the benefits of
including them.
The San Bruno Mountain Area HCP overlaps with the critical habitat
designation on San Bruno Mountain. The bay checkerspot is believed to
have been extirpated from the mountain since about 1986. The San Bruno
Mountain Area HCP does not discuss the bay checkerspot in detail, and
the Incidental Take Permit for this HCP currently does not include the
subspecies. Therefore, we have not excluded the area covered by this
HCP from the critical habitat designation. Any future Service or other
Federal agency involvement in activities on San Bruno Mountain, such as
habitat restoration, may require section 7 consultation if there are
likely to be effects on bay checkerspot critical habitat.
The Pacific Gas and Electric (PG & E) Metcalf-Edenvale/Metcalf-
Monte Vista HCP covers only about 4 ha (10 ac) in the Santa Teresa
Hills, San Vicente-Calero, and Tulare Hill Corridor critical habitat
units. Because the HCP expires in November 2001, and the permitted
project is substantially complete within critical habitat areas, we are
not excluding lands covered under this short-term HCP from our critical
habitat proposal. We believe that no formal
[[Page 21461]]
consultation on any remaining work covered by the HCP will be
necessary.
In the event that future HCPs covering the bay checkerspot are
developed within the boundaries of designated critical habitat, we will
work with applicants to ensure that the HCPs provide for protection and
management of habitat areas essential for the conservation of the bay
checkerspot by either directing development and habitat modification to
nonessential areas, or appropriately modifying activities within
essential habitat areas so that such activities will not adversely
modify the primary constituent elements. The HCP development process
provides an opportunity for more intensive data collection and analysis
regarding the use of particular habitat areas by the bay checkerspot.
The process also enables us to conduct detailed evaluations of the
importance of such lands to the long-term survival of the subspecies in
the context of constructing a biologically configured system of
interlinked habitat blocks.
We will provide technical assistance and work closely with
applicants throughout the development of future HCPs to identify lands
essential for the long-term conservation of the bay checkerspot and
appropriate management for those lands. Preliminary HCPs are being
discussed for listed and non-listed species within the range of the bay
checkerspot in areas designated herein as critical habitat. These HCPs,
coupled with appropriate adaptive management, should provide for the
conservation of the subspecies. If these HCPs, or others, that address
the bay checkerspot are ultimately approved, we will reassess the
critical habitat boundaries in light of the HCPs. We will seek to
undertake this review when an HCP is approved, but funding constraints
may influence the timing of such a review.
Summary of Comments and Recommendations
In the October 16, 2000, proposed rule (65 FR 61218), we requested
all interested parties to submit comments on the specifics of the
proposal including information, policy, treatment of HCPs, and proposed
critical habitat boundaries as provided in the proposed rule. The first
comment period closed on December 15, 2000. The comment period was
reopened from February 9, 2001, to March 12, 2001, (66 FR 9683) to
allow for additional comments on both the proposed rule and the draft
economic analysis. Although not stated in the Federal Register
notice of February 9, 2001, we accepted all comments received from
October 16, 2000, to March 12, 2001, and entered them into the
administrative record for the rule.
We contacted all appropriate State and Federal agencies, Tribes,
county governments, elected officials, and other interested parties and
invited them to comment. In addition, we invited public comment through
the publication of notices and display ads to announce the public
hearing in the following newspapers in California: the San Mateo County
Times and the Palo Alto Weekly. These announcements were published on
October 20 and October 25, 2000, respectively. In these notices and the
proposed rule, we announced the date and time of one public hearing
that was held on the proposed rule. This hearing was in Newark,
California, on October 30, 2000. A transcript of this hearing is
available for inspection (see ADDRESSES section).
When the comment period was re-opened, we sent out notices of the
re-opening to all parties on a mailing list for the bay checkerspot.
Additionally, we held one informational meeting on February 22, 2001,
in San Jose, California.
We requested four professional ecologists, who have familiarity
with bay checkerspot butterflies and/or butterfly metapopulation
dynamics, to peer review the proposed critical habitat designation.
Three of the peer reviewers submitted comments on the proposed critical
habitat designation, and one did not respond.
One peer reviewer stated that the proposed rule was ``* * *
formulated utilizing technically accurate and up-to-date information *
* *'' about the bay checkerspot, and that ``* * * the criteria or
primary constituent elements * * *'' used to identify and propose
critical habitat ``* * * are appropriate to identify the large-scale
boundaries of critical habitat units.'' He found that the maps and
descriptions of the 15 proposed critical habitat units we prepared ``*
* * accurately delimit the approximate boundaries of potential habitat
at every location.''
He recommended we review the status of Euphydryas editha
populations of uncertain subspecific status in San Benito and San
Luis Obispo counties. We note that we will continue to review and
consider scientific data and peer consensus on the subspecific status
of uncertain Euphydryas editha populations as it becomes
available. We believe that the best information available at this time
supports proceeding with this rule substantially as proposed. The Act
provides procedures under section 4 for modifying species listings and
critical habitat designations as may be appropriate in light of any new
information that may be developed.
The reviewer agreed with our assessment of the value of the Tulare
Hill unit as a dispersal corridor for the bay checkerspot butterfly to
connect populations that lie east and west of that unit. He contrasted
Tulare Hill with more isolated sites such as San Bruno Mountain and
Communications Hill, where the distance to existing bay checkerspot
butterfly populations may be more than a butterfly normally disperses,
and intervening areas are urbanized. We agree that the San Bruno
Mountain site may require introduction in order to establish and
perhaps to maintain a bay checkerspot population; however, we believe
Communications Hill is within normal flight range of other Santa Clara
Valley metapopulation units.
A second peer reviewer generally supported the rule, stating that
``* * * it does an excellent job of reviewing and interpreting bay
checkerspot population biology, habitat requirements, and
distribution.'' In particular, she noted that the ridge including the
Kirby and Metcalf units [which we call Coyote Ridge] is very important
to the persistence of the Santa Clara County metapopulation, supporting
multiple demographic units. In her research Coyote Ridge appeared to be
a stable ``source'' that plays a major role in sustaining the species
in the region. The reviewer suggested that the Edgewood unit serves the
same ``source role'' in the San Mateo County metapopulation, and stated
that it is important to protect Edgewood as the last remainder of
whatever unique genetic variants of the bay checkerspot may exist in
that region.
The second reviewer mentioned Silver Creek, Santa Teresa Hills, and
Morgan Hill as having especially good potential for strong populations
of the bay checkerspot butterfly, but that the Santa Teresa Hills, such
as the ungrazed Santa Teresa County Park, may need more grazing to
achieve its full potential as a large block of habitat. She stated that
during her field studies, the only critical habitat unit she did not
think had much potential as bay checkerspot habitat was Communications
Hill, recalling it as being disturbed and grassy with few native forb-
dominated meadows. We note that we have received a recent host plant
survey of a portion of Communications Hill that documents substantial
areas of larval food plants and adult nectar plants (Arnold 2000).
The third reviewer also generally supported the rule, finding it
``carefully
[[Page 21462]]
constructed, comprehensive, and well justified. * * * Importantly, the
critical habitat areas contain important dispersal corridors between
serpentine patches, and account for the dynamic nature of bay
checkerspot metapopulations, with local extinctions and
recolonizations.''
This reviewer made extensive comments about nitrogen deposition,
stating that the preponderance of scientific evidence and opinion is
that the serpentine grasslands in question are highly sensitive to
nitrogen additions, that nitrogen deposition can lead to degradation of
habitat, and that excess nitrogen deposition from smog may be the
single biggest immediate threat to the bay checkerspot.
The reviewer also stated that well-managed grazing is vital to the
recovery of the bay checkerspot, specifically mentioning public lands
in the Santa Teresa Hills unit as being in need of grazing to reverse
deteriorating habitat quality. He estimated that one formerly degraded
site in the Silver Creek unit recovered and greatly increased host
plant and nectar plant density in about five years of grazing. We
concur that recovery of habitat quality with grazing is feasible and
documented.
The reviewer stated that Communications Hill in its current state
is unlikely to support bay checkerspot populations, but also stated
that the proposed unit boundaries ``contain the remaining habitat.'' He
considers the Communications Hill habitat relatively warm and dry, with
few north-facing slopes, degraded by lack of grazing, and generally of
low priority relative to higher quality habitats elsewhere. The Service
believes that Communications Hill is likely to be occupied by the bay
checkerspot, and we discuss why in detail in our responses to public
comment regarding Communications Hill, below. The reviewer suggested
one additional unit in the vicinity of Canada Garcia and Manzanita
Ridge (west of Chesbro Reservoir, Santa Clara County), with more than
100 ha (247 ac) of serpentine and a good mix of slopes and aspects.
However, we lack adequate information about this area to justify
including it in the critical habitat designation at this time. The Act
provides opportunity for later revision of critical habitat designation
through petition procedures under section 4(b)(3)(D). Further unit-
specific comments by the third reviewer are covered below.
We received a total of 1,037 oral and written comments during the
comment periods. In total, oral and written comments were received from
1 State office, 5 local governments, and 1,031 private individuals or
organizations. We reviewed all comments received for substantive issues
and new information regarding critical habitat and the bay checkerspot.
Of the comments we received, 1,006 supported designation, 24 were
opposed to it, and 7 provided information or declined to oppose or
support the designation. Similar comments were grouped into four
general issues relating specifically to the proposed critical habitat
determination and draft economic analysis on the proposed
determination. These are addressed in the following summary.
Issue 1: Biological Justification, Methodology, and Regulatory Comments
(1) Comment: One commenter stated that the Service should
concentrate its critical habitat efforts for the bay checkerspot on
those sites where the bay checkerspot exists and which, therefore,
truly provide potential conservation benefits to the subspecies.
Our Response: We did concentrate on occupied sites, and
have only included unoccupied sites where they are essential to the
conservation of the subspecies. The unoccupied sites are essential, as
described in the bay checkerspot's Recovery Plan (Service 1998),
because of the metapopulation dynamics exhibited by the bay
checkerspot, and because they are representative of the historic
geographical and ecological distribution of the subspecies.
(2) Comment: A commenter was concerned that the activities
described in the proposed rule that may affect critical habitat under
section 7 consultation were broadly defined and, combined with other
species listings and critical habitat designations, have the net effect
of establishing the Service as the sole arbiter of land use decisions.
It was suggested that the Service narrow the defined activities that
may affect critical habitat. The commenter also stated that water
contracting and operations carried out by Federal agencies are not a
direct or indirect cause of loss of habitat or cause for endangerment
of the subspecies and, therefore. should not require section 7
consultation. It was also stated that sale or lease of private property
does not result in habitat loss and should be deleted from the rule.
Our Response: We provide the list of activities that may
affect critical habitat to assist Federal agencies when they review
their actions and determine whether critical habitat may be affected.
The list is wide-ranging because diverse Federal agencies have broad
responsibilities under the Act to protect and conserve listed species
and critical habitat. The list in no way conveys land use jurisdiction
to the Service. The trigger for section 7 consultation is whether a
Federal action may affect a listed species or critical habitat. Federal
water contracts and operations that meet this criterion are required to
consult. Sales or leasing of property will only be subject to
consultation on critical habitat when a Federal agency is funding,
authorizing, or carrying out the action, and the sale or lease may
affect critical habitat.
(3) Comment: One commenter said that if the Service is
going to use fragmentation as a reason for designating critical habitat
(Background section), it should develop a quantitative assessment of
how much fragmentation has taken place. Are the urban developments
replacing woodlands, chaparral, or other habitats between areas of
serpentine grassland a detriment or a benefit to the bay checkerspot?
These developments may be a detriment, because of reduced resting area,
increased obstacles, and pesticide; however, they could be a benefit by
reducing predatory birds. The commenter also asked the Service to
consider and insert why butterflies may be avoiding wooded or scrub
habitats, as this may be a predator avoidance behavior.
Our Response: A quantitative analysis of habitat
fragmentation is not required to designate critical habitat, and is
beyond the scope of this rulemaking. It is not known why bay
checkerspot butterflies appear to avoid wooded or scrub habitats. We
are not aware of any scientific reports of bay checkerspots exhibiting
predator avoidance behavior.
(4) Comment: One commenter said the indirect effects of
added nitrogen deposition from increased automobile traffic on plant
community structure need to be addressed. Concerns about the effects of
nitrogen deposition on the bay checkerspot were also expressed by a
peer reviewer.
Our Response: Nitrogen oxides from increased automobile
traffic contribute to excess nitrogen deposition on surrounding
habitats. Nitrogen deposition and its effects are briefly addressed in
the Background section. We agree that scientific studies, such as those
summarized in our Recovery Plan (Service 1998), show that automobiles
and many other air pollution sources produce excess nitrogen oxides. A
recent study found that nitrogen deposition from air pollution on
Coyote Ridge, which includes the Kirby, Metcalf, and Silver Creek
units, is already likely to be at levels adversely affecting serpentine
plant community
[[Page 21463]]
structure, with negative effects on the bay checkerspot (Weiss 1999).
We have modified the list of activities that may affect critical
habitat in the section 7 Consultation section to address excess
nitrogen deposition more clearly, by listing deposition as well as
application of fertilizers, pollutants, and other chemicals. In ongoing
consultation and discussions with the Corps of Engineers, the Federal
Highway Administration, the City of San Jose, and the County of Santa
Clara, we are currently seeking to address the risk that excess
nitrogen deposition poses to the bay checkerspot butterfly.
(5) Comment: One commenter said that a higher proportion of
the outcrops on the peninsula than in Santa Clara County might
reasonably be proposed for critical habitat.
Our Response: We are aware of, and considered, several
serpentine outcrop areas on the San Francisco peninsula when developing
the proposed rule. However, the remaining undeveloped area of each of
these sites is small, the topographic diversity is generally poor, and
most are degraded and exposed to significant threats, such as lying
directly adjacent to an eight-lane freeway. All are considered to have
been unoccupied by the bay checkerspot for one or more decades.
(6) Comment: One commenter asked what percentage of total
bay checkerspot habitat is included in the critical habitat designation
and how much area outside this designated area is likely to contain bay
checkerspot.
Our Response: We do not currently have comprehensive
figures on the total area or location of bay checkerspot habitat or the
status of all bay checkerspot populations. In our estimation, this
critical habitat designation includes the majority of remaining bay
checkerspot habitat in Santa Clara and San Mateo counties, and an even
higher proportion of currently existing bay checkerspot populations.
However, bay checkerspot populations and suitable habitat do exist
outside of designated critical habitat. For example, bay checkerspot
butterflies exist in a locality on serpentine soils near Uvas Reservoir
in Santa Clara County, and at several other serpentine outcrops west of
the foothills of the Santa Clara Valley. We did not include these areas
in critical habitat because available data do not indicate they are
essential to the conservation of the subspecies, or because we lack
sufficient information on the localities to make a determination.
(7) Comment: One commenter said that if assessor's parcel
numbers were identified or assessor's maps were used to identify parcel
ownership, then information on land use on those parcels would also be
available. The designation of critical habitat appears to have skipped
an important part of the analysis and this information should be
included and reviewed.
Our Response: We did not use assessor's parcel maps in
developing our designation. Instead, subsequent to the bay checkerspot
critical habitat proposal on October 16, 2000 (65 FR 61218), the County
of Santa Clara sent us a list of property owners potentially interested
in the designation. We contacted these landowners by mail and provided
them the opportunity to comment about the proposed rule and draft
economic analysis. Several landowners commented on these two documents
and provided information that helped us refine our final critical
habitat designation.
(8) Comment: Several commenters felt that the critical
habitat designation should encourage viable grazing activities.
Our Response: We agree that sustainable grazing practices
are generally compatible with bay checkerspot habitat and conservation,
and that in some areas or at certain times the removal of grazing may
actually be a threat. The rule states this in the Background and the
Effects of Critical Habitat Designation sections.
(9) Comment: A commenter asked what types of development
would typically be allowed in critical habitat areas, what would be the
threshold that would trigger a Federal permit, what Federal agencies
would be involved in issuance of these permits, to which agencies would
the county refer development applications, and what typical mitigation
measures would be required in a development proposal to ensure adequate
habitat protection.
Our Response: There is no such thing as a Federal permit
for development in critical habitat units. Critical habitat identifies
specific areas that have the physical and biological features that are
essential to the conservation of a listed species, and that may require
special management considerations or protection. Federal agencies are
required to consult with us only if an action they are authorizing,
funding, or carrying out, in whole or in part, may affect critical
habitat. We do not believe any new county procedures for critical
habitat would be required beyond what the county should already have in
place to protect the threatened bay checkerspot butterfly. Refer to the
section above that discusses section 7 or the Regulatory Planning and
Review and Regulatory Flexibility Act sections under Required
Determinations below for more information as to what potential Federal
agencies may initiate a section 7 consultation and the types of
activities that may be involved.
(10) Comment: One commenter asked why we had proposed so
many contiguous units. He recommended a single unit should be proposed
for the Coyote Ridge area.
Our Response: These units have distinct bay checkerspot
populations and are connected by dispersal habitat. Separate units
allow us to evaluate the effects resulting from any Federal actions on
unit populations individually, rather than lumping them all together.
(11) Comment: One commenter requested that information on
the distances the Edgewood Park/Triangle, Jasper Ridge, and San Bruno
Mountain units are from other units be provided.
Our Response: We added distance information to the
narrative discussion of these units. Please see that section.
(12) Comment: One commenter stated that the Service should
provide quantitative or qualitative measures for the primary
constituent elements. The commenter proposed additions to and omissions
from the primary constituent elements, adding: minimum size areas such
as at least 1.6 ha (4 ac), north-facing serpentine slopes with dense
stands of Plantago erecta, a diversity of north and nearby
south- and west-facing slopes, at least 152 m (500 ft) in elevation,
and serpentine soil; and omitting pollinators, stable holes, or cracks
in soil, and wetlands.
Our Response: The ``may affect'' criterion that triggers
Federal agencies to consult under section 7 of the Act is a broad,
qualitative standard. We believe that precise quantitative standards
for habitat are unnecessary and would overstate the scientific
understanding of the bay checkerspot, its environments, and its needs.
For example, Plantago erecta densities vary greatly from year
to year, and what bay checkerspot larvae need for a ``dense'' stand of
Plantago erecta has not been documented. We have reviewed and
made alterations in the wording of the primary constituent elements
designation, and we believe the final language suitably captures the
needs of the subspecies in a manner that will be useful to Federal
agencies in determining whether actions they fund, authorize, or carry
out may affect critical habitat.
(13) Comment: One commenter felt some of the primary
constituent elements were either difficult to measure, or are
considered generally
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unimportant for the subspecies, such as wetlands.
Our Response: We provide justification for the primary
constituent elements stated above (see Background section). We also
provided citations stating the importance of wetlands to the bay
checkerspot. For example, the article cited regarding occasional
wetland use by bay checkerspot (Launer et al. 1993) is co-
authored by six well-known ecologists and biologists, and states ``our
observations are consistent with the hypothesis that (bay checkerspot)
butterflies are visiting moist areas in order to replenish essential
nutrients or water expended during mating, gamete (egg or sperm)
production, or general metabolism.'' They go on to say that local
population persistence may be enhanced by moist areas, and that canyon
bottoms and moist areas may need to be considered in conservation
planning for the bay checkerspot.
(14) Comment: One commenter objected that the size of
patches of host plants and the average density of Plantago erecta
are not provided for any of the units, even though data exist for
many. The minimum patch size of Plantago erecta necessary to support a
population of bay checkerspot should also be provided.
Our Response: While we would be interested in reviewing the
data on Plantago erecta referred to in the comment,
Plantago erecta is an annual plant whose year-to-year abundance
is strongly affected by abiotic and biotic environmental conditions. As
such, information on its present abundance is not necessarily a good
indicator of conditions next year or over the long run. Regarding the
minimum amount of Plantago erecta needed to support a
population of bay checkerspot, we are not aware of any studies in the
literature of what this amount might be. Also, the mobility and
metapopulation dynamics of the bay checkerspot would need to be
considered in evaluating the relevance of the size of any particular
patch of food plants.
(15) Comment: One commenter asked whether the Service will
require all of the proposed primary constituent elements to be present,
or only one or two to qualify a site as critical habitat.
Our Response: We clarified the language regarding the
primary constituent elements in the final rule (see the Primary
Constituent Elements section of this rule). All areas within the legal
descriptions are considered critical habitat except for existing
manmade features and structures, such as buildings, roads, railroads,
and urban development. All critical habitat areas contain one or more
of the primary constituent elements.
(16) Comment: A commenter stated that many farmers and
ranchers are concerned that their current agricultural practices could
be impacted. They fear cropping patterns, water conservation, and other
practices may be limited with the critical habitat designation because
these practices may now impact the bay checkerspot.
Our Response: With the changes made from the proposed rule,
very little, if any, crop land remains within the critical habitat
boundaries. Normal ranching practice will be unaffected by bay
checkerspot critical habitat designation.
(17) Comment: A commenter representing certain landowners
in the area of the proposed Kalana Hills unit said substantial areas
were included within the borders of the proposed critical habitat area
that clearly lack any of the primary constituent elements for the bay
checkerspot. For instance, the Service included area that is non-
serpentine and presently in cultivation in Kalana Hills unit.