[Federal Register Volume 62, Number 182 (Friday, September 19, 1997)]
[Proposed Rules]
[Pages 49191-49193]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24806]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17


Endangered and Threatened Wildlife and Plants; Notice of 
Reclassification of Ten Candidate Taxa

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of candidate taxa reclassification.

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SUMMARY: In this document, the U.S. Fish and Wildlife Service (Service) 
provides explanation for a change in the status of seven animal and 
three plant taxa that are under review for possible addition to the 
Lists of Endangered and Threatened Wildlife and Plants (Lists)

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under the Endangered Species Act of 1973, as amended (Act). These 10 
taxa are being removed from candidate status at this time.

ADDRESSES: Questions concerning this document should be submitted to 
the Chief, Division of Endangered Species, U.S. Fish and Wildlife 
Service, 1849 C Street, NW., Mail Stop 452 ARLSQ, Washington, DC 20240.

FOR FURTHER INFORMATION CONTACT: E. LaVerne Smith, Chief, Division of 
Endangered Species (see ADDRESSES section) (telephone: 703/358-2171).

SUPPLEMENTARY INFORMATION:

Background

    Candidate taxa are those taxa for which the Service has on file 
sufficient information to support issuance of a proposed rule to list 
under the Act. The Service recently completed its annual review of all 
candidate taxa. The results of this review indicate that several taxa 
should be removed from candidate status. This notice provides specific 
explanations for the reclassification of seven animal and three plant 
taxa.
    It is important to note that candidate assessment is an ongoing 
function and changes in status should be expected. Taxa that are 
removed from the candidate list may be restored to candidate status if 
additional information supporting such a change becomes available to 
the Service. Requests for such information were issued by the Service 
in the 1996 plant and animal candidate notice of review (61 FR 7596; 
February 28, 1996). A revised notice of review, requesting updated 
information on candidate taxa, is published concurrently in the Federal 
Register with this notice.

Findings

    The Gulf Coast hog-nosed skunk (Conepatus leuconotus texensis) was 
considered to be restricted to southern Texas and northern Mexico as 
far west as San Luis Potosi and south to Veracruz. However, the results 
of a recently completed taxonomic study of the genus Conepatus in the 
United States and Mexico show no clear difference between the two 
previously delineated North American species in this genus, C. 
leuconotus and C. mesoleucus, with respect to color patterns, 
anatomical measurements, or mitochondrial DNA. The results indicate 
that most subspecies of both species, including C. leuconotus texensis, 
should be combined under C. leuconotus leuconotus. Evidence is lacking 
that hog-nosed skunks in the South Texas region are geographically 
disjunct from those to the north and west. In addition, information is 
lacking that the taxonomic entity to which these South Texas hog-nosed 
skunks now belong (C. leuconotus leuconotus) is in danger of extinction 
within the foreseeable future. Based on this information, acceptance of 
the Gulf Coast hog-nosed skunk as a candidate taxon is not warranted.
    The Ramsey Canyon leopard frog (Rana subaquavocalis) occurs at two 
sites in Ramsey and Brown canyons in the Huachuca Mountains of 
southeastern Arizona. The species was considered threatened by changes 
to its habitat and genetic problems associated with small populations. 
A Conservation Agreement among the landowners and State and Federal 
agencies is currently being implemented which provides for the 
conservation of the Ramsey Canyon leopard frog through captive breeding 
and reintroduction, acquisition of habitat, and population and habitat 
surveys. The Ramsey Canyon population receives additional protection 
due to its location within The Nature Conservancy's Ramsey Canyon 
Preserve. Based on this information, continuation of candidate status 
for this species is not warranted.
    The High Rock Spring tui chub (Gila bicolor ssp.), a small minnow, 
was historically known from three formerly connected spring systems in 
California and Nevada. This fish was extirpated from the two sites in 
Nevada as a result of increased pumping of groundwater adjacent to the 
surface pools it inhabited. In 1982, the California Department of Fish 
and Game issued an aquaculture permit to the landowner of the 
California site to rear Mozambique tilapia (Oreochromis mossambica). 
Inadequate screening of the rearing facilities allowed tilapia to 
escape into the spring system. By 1989, the High Rock Spring tui chub 
was extirpated from the site as a result of competition from and 
predation by the introduced tilapia. The High Rock Spring tui chub was 
confirmed to be extinct in 1993. Because it is considered extinct, the 
High Rock Spring tui chub is being removed from the list of candidate 
taxa.
    Three pomace flies (Drosophila) from Hawaii are being removed from 
the list of candidates because they are believed to be extinct. 
Drosophila alsophila was always a rare species, known from only two 
localities on Hualalai volcano on the island of Hawaii where it bred in 
the stems of Urera and Charpentiera. Drosophila psilotarsalis was also 
always rare, known from a single locality on the island of Hawaii where 
adults were found only in association with Charpentiera. Drosophila 
toxochaeta was a rare species, known from a single locality in wet 
forest on the island of Molokai. These pomace flies were believed to be 
extant based on historical collection records, habitat assessments, and 
surveys in the 1980's by Drosophila researchers. However, recent 
careful efforts by Drosophila researchers at the University of Hawaii 
to recollect these species have failed, and they are now believed to be 
extinct.
    The Marianas euploea butterfly (Euploea eleutho) was endemic to the 
Mariana Islands and was historically recorded from Guam, Rota, Saipan, 
and the northern islands of Alamagan and Anatahan. It was common on 
Guam in 1936, but has not been collected from Guam, Rota, or Saipan 
since 1946. Surveys in 1995 confirmed that it is extinct on these 
southern islands. In the 1970's, this butterfly was recorded on 
Alamagan and Anatahan. Members of a recent Japanese entomological 
expedition initially believed that they had rediscovered this species 
on some of the small, remote northern Mariana Islands. However, their 
collections proved to be a different species. The Japanese 
entomologists' failure to locate the Marianas euploea butterfly, 
despite the thoroughness of their search for butterflies, is the basis 
for the Service considering that this species is currently extinct 
throughout its range. Because it is believed to be extinct, this 
species is being removed from the list of candidates.
    The Surf thistle (Cirsium rhothophilum) is a bush-like biennial or 
short-lived perennial member of the sunflower family that is endemic to 
southern California. It occurs only in the narrow strip of habitat 
between wind-blown beach and stabilized dunes. The species was 
considered to be threatened by oil production, missile facility 
construction, beach users, recreational vehicles, cattle, and non-
native ice plants. Approximately 57 percent of the recorded locations, 
with 80 percent of the total number of plants, are on Vandenberg Air 
Force Base within designated special management areas for the western 
snowy plover (Charadrius alexandrinus nivosus), a listed threatened 
species. The protection and management of these western snowy plover 
areas by the Air Force have also protected the Surf thistle 
sufficiently to stabilize the population. Based on this information, 
continuation of candidate status for this species is not warranted.
    The Merced clarkia (Clarkia lingulata) is an annual plant of the 
evening primrose family that is endemic to central California. It 
occurs in the understory of pine/oak foothill woodlands and is known 
from only two

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localities in Mariposa County. Both localities are steep north-facing 
slopes within the Sierra National Forest and partly within a California 
Department of Transportation (Caltrans) right-of-way. The species was 
considered to be threatened by road construction and maintenance 
activities, power line maintenance activities, and landslides. 
Implementation of protection measures through a Memorandum of 
Understanding signed by the Forest Service, Caltrans, and Pacific Gas 
and Electric has reduced the level of threats to the Merced clarkia. 
The available information indicates that the degree of the threats to 
the Merced clarkia does not warrant issuance of a proposed rule nor 
continuation of candidate status for this species.
    The San Gabriel Mountains dudleya (Dudleya densiflora) is a white 
or pink-flowered perennial of the stonecrop family that is endemic to 
southern California. It occurs on steep cliffs and canyon walls within 
chaparral, oak woodland, and riparian woodlands. This species is known 
from four populations within a 9 square-mile area along the southern 
face of the San Gabriel Mountains in Los Angeles County. The species 
was considered to be threatened by mining, road maintenance, and 
recreational activities. The San Gabriel Mountains dudleya is being 
removed from candidate status because about 75 percent of the 
subpopulations of the species occur on steep cliffs and canyon walls on 
U.S. Forest Service lands and are not threatened by habitat 
modification at this time.

Author

    This notice was compiled from materials supplied by staff 
biologists located in the Service's regional and field offices. The 
materials were compiled by Martin J. Miller, Division of Endangered 
Species (see ADDRESSES section).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended, 16 U.S.C. 1531 et seq.

    Dated: September 3, 1997.
Jamie Rappaport Clark,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 97-24806 Filed 9-18-97; 8:45 am]
BILLING CODE 4310-55-P