[Federal Register Volume 59, Number 170 (Friday, September 2, 1994)]
[Proposed Rules]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-21785]
[[Page Unknown]]
[Federal Register: September 2, 1994]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 1-Year Finding for
a Petition To List the Pacific Coast Population of the Cactus Wren
Under the Endangered Species Act
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 1-year petition finding.
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SUMMARY: The Fish and Wildlife Service (Service), pursuant to the
Endangered Species Act of 1973, as amended (Act), announces a 1-year
finding on a petition to add the Pacific coast population of the cactus
wren (Campylorhynchus brunneicapillus couesi) to the List of Endangered
and Threatened Wildlife. After a review of all available scientific and
commercial information, the Service determines that listing is not
warranted at this time and hereby transfers the petitioned entity from
category 2 to category 3B of the Candidate Notice of Review. The
Service concludes that the cactus wrens occupying coastal southern
California do not constitute a distinct population segment. Therefore,
the Service concludes that the Pacific coast population of the cactus
wren is not a listable entity.
DATES: The finding announced in this document was made on August 29,
1994. Comments and information may be submitted until further notice.
ADDRESSES: Comments and materials regarding this petition finding may
be submitted to the Field Supervisor, U.S. Fish and Wildlife Service,
Carlsbad Field Office, 2730 Loker Avenue West, Carlsbad, California
92008. The complete file for this notice, including the petitions,
administrative finding, supporting data, and comments, is available for
inspection, by appointment, during normal business hours at the above
address.
FOR FURTHER INFORMATION CONTACT:
Mr. Gail C. Kobetich, Field Supervisor, at the address listed above
(telephone 619/431-9440).
SUPPLEMENTARY INFORMATION:
Background
Pursuant to section 4(b)(3)(B) of the Act, the Service is required
to make a finding within 12 months of the date of the receipt of a
petition to revise the Lists of Endangered and Threatened Wildlife and
Plants on whether the petition is (a) not warranted, (b) warranted, or
(c) warranted but precluded for immediate proposal by other proposals
of higher priority. Section 4(b)(3)(C) requires that petitions for
which the requested action is found to be ``warranted but precluded''
should be treated as though resubmitted on the date of such finding.
Therefore, a subsequent finding should be made within 12 months.
On September 21, 1990, the Service received petitions from the San
Diego Biodiversity Project and Palomar Audubon Society to list the
``San Diego cactus wren'', Campylorhynchus brunneicapillus
sandiegensis, as an endangered species pursuant to section 4 of the
Act. The San Diego cactus wren, as described, occurs from San Juan
Creek in southern Orange County through western San Diego County
southward to Valle de las Palmas in Baja California, which is just
south of the U.S.-Mexico border.
The American Ornithologists' Union Committee on Classification and
Nomenclature (Committee) did not recognize the San Diego cactus wren
(C. b. sandiegensis) as a subspecies of the cactus wren
(Campylorhynchus brunneicapillus). The Committee has concluded that C.
b. sandiegensis is intermediate between C. b. couesi, a widespread
subspecies found in southwestern United States and northern, mainland
Mexico, and C. b. bryanti, a suspecies recognized as occurring from San
Diego County, California, to northern Baja California, Mexico (B.
Monroe, in litt., 1990; R. Banks, in litt, 1994).
The Service considers the Committee to be the recognized authority
on the taxonomy of the birds of North America. Since the conclusion of
the committee is that C. b. sandiegensis likely only represents an
intermediate form between two recognized subspecies of cactus wren, it
is not currently under consideration for addition to the Federal List
of Endangered and Threatened Wildlife and Plants.
On March 22, 1991, the Service announced its 90-day finding on the
petitions (56 FR 12146), and indicated that we would treat the
petitions to list C. b. sandiegensis as a petition to list the coastal
population of C. b. couesi, because the cactus wrens residing in
coastal California may be disjunct from other cactus wrens, and may
constitute a distinct vertebrate population segment that could qualify
for listing under the Act. Under section 3(15) of the Act the term
``species'' includes any distinct population segment of any species of
vertebrate fish and wildlife which interbreeds when mature. Thus, we
indicated that the petition had presented substantial information
indicating that the requested action may be warranted. Based upon our
reevaluation of information received, the Service concludes that the
coastal population of cactus wren consists of Pacific coastal portions
of C. b couesi and C. b. bryanti.
However, Congressional intent indicates that the Service is to list
populations only ``sparingly''. In determining the appropriateness of
listing a vertebrate population segment under the Act, the Service
considers available scientific evidence regarding the population's
discreetness or distinctiveness and regarding the population's
significance to the species as a whole.
The cactus wren is a resident species, and numbers of cactus wrens
residing in coastal sage scrub of coastal southern California have
declined as a result of the expressed effects of many of the same
factors that have similarly impacted the largely sympatric, threatened
coastal California gnatcatcher (Polioptila californica californica).
All of the published literature on the status of coastal sage scrub
vegetation types in California supports the conclusion that this plant
community is one of the most depleted habitat types in the United
States.
However, it is currently evident that the cactus wrens residing in
coastal sage scrub plant communities are not distinct from other cactus
wrens. Therefore, cactus wrens occupying coastal southern California do
not constitute a distinct vertebrate population segment. For instance,
although the coastal birds almost always nest in cactus, cactus is a
preferred nesting substrate of cactus wrens elsewhere in California and
in the remainder of the species' range in the United States. Perhaps
more importantly, no apparent morphological or other morphometric
differences have been detected to date that distinguish coastal birds
from other cactus wrens.
In addition, it is apparent that the habitat preference of coastal
birds (coastal sage scrub) does not readily separate them from other
members of the subspecies. Several treatments exist describing various
types of scrub communities in southern California and Baja California.
The coastal sage scrub plant formation grades into coastal succulent
scrub and eventually into Sonoran desert scrub. Although some gaps in
the range of the species may exist, birds representing C. b. bryanti or
C. b. couesi, as currently defined by the American Ornithologist's
Union (R. Banks, in litt., 1994), likely occupy all of these ``scrub''
plant communities or formations. Hence, because cactus wrens evidently
occupy several plant communities and are not isolated in habitat, the
Service concludes that providing protection pursuant to the Act for
birds living in some (but not all) of these plant communities and
habitats is inappropriate.
Furthermore, the cactus wrens occupying coastal southern California
are not likely significant to the continued existence of a species that
occurs in portions of southern California, southern Nevada, Arizona,
New Mexico, Utah, and Texas, in the United States, and mainland Mexico.
The species is relatively common throughout much of its range. However,
since the birds occupying coastal southern California are not distinct,
the issue of significance need not be addressed.
This finding announced herein is not intended to discount the
importance of the coastal sage scrub ecosystem in southern California,
which is the subject of intense multispecies and ecosystem planning
efforts that have been undertaken and endorsed by the Service; the
Secretary of Interior; the Resources Agency, State of California; the
California Department of Fish and Game; numerous local governments;
citizens' groups; and individual citizens. Cactus wrens living in
coastal southern California have declined in numbers, and coastal sage
scrub habitats are becoming increasingly depleted. Efforts to conserve
these depleted habitats will be of benefit to cactus wrens residing in
coastal southern California, Federal candidate species, and other
sensitive species.
In the absence of sufficient evidence that a listable entity
exists, the Service concludes that it is appropriate to transfer the
``coastal population of the cactus wren'' from category 2 candidate
status to category 3B. Category 3B species are taxa that, on the basis
of current taxonomic understanding, do not represent distinct taxa,
including vertebrate populations, meeting the Act's definition of
``species.'' Such taxa could be reevaluated in the future on the basis
of new information. In that regard, the service will continue to accept
information on the taxonomy and distinctness of cactus wren taxa and
the significance of the Pacific coast population segment.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, and Transportation.
Dated: August 29, 1994.
Mollie H. Beattie,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 94-21785 Filed 9-1-94; 8:45 am]
BILLING CODE 4310-55-M
