[Federal Register Volume 59, Number 56 (Wednesday, March 23, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-6791]


[[Page Unknown]]

[Federal Register: March 23, 1994]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service
50 CFR Part 17 
RIN 1018-AC13 
 

Endangered and Threatened Wildlife and Plants; Proposal to List 
the San Xavier Talussnail as Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes to list 
the San Xavier talussnail (Sonorella eremita) as an endangered species 
under the Endangered Species Act of 1973, as amended (Act). The San 
Xavier talussnail is found only in an area of 15 by 30 meters (m) (50 
by 100 feet (ft)) on private land in Pima County, Arizona. The primary 
threat to the species results from its vulnerability to habitat 
disturbances that would remove talus, increase interstitial soil, or 
alter moisture accumulation and retention. This proposal, if made 
final, would implement Federal protection provided by the Act for the 
San Xavier talussnail. The Service seeks data and comments from the 
public on this proposal.

DATES: Comments from all interested parties must be received by May 23, 
1994. Public hearing requests must be received by May 9, 1994.

ADDRESSES: Comments and materials concerning this proposal should be 
sent to the Field Supervisor, Arizona Ecological Services Field Office, 
U.S. Fish and Wildlife Service, 3616 West Thomas Road, Suite 6, 
Phoenix, Arizona 85019. Comments and materials received will be 
available for public inspection, by appointment, during normal business 
hours at the above address.

FOR FURTHER INFORMATION CONTACT: Debra T. Bills, at the above address 
(602/379-4720).

SUPPLEMENTARY INFORMATION:

Background

    The San Xavier talussnail (Sonorella eremita) is a land snail, 
first described in 1910 by H.A. Pilsbry and L.E. Daniels (Pilsbry and 
Ferriss 1915). The species has a globose shell with as many as 4.5 
whorls, a white to pinkish tint, and a chestnut-brown shoulder band. It 
is approximately 19 millimeters (0.7 inches) in diameter. This is the 
only land snail fitting this description in the Mineral Hills area, but 
its shell is very typical of desert Sonorella (Pilsbry and Ferriss 
1915).
    The San Xavier talussnail lives in a deep, northwestward-facing, 
limestone rockslide in Pima County, Arizona. Its habitat is protected 
from drying effects of the sun by outcrops of limestone and decomposed 
granite to the northeast and southwest, and by the hill itself to the 
southeast (Pilsbry and Ferriss 1915, Hoffman 1990). The vegetation, 
slope of the hillside, and depth of the slide provide necessary 
moisture conditions. This talussnail is similar to other Sonorella 
species in that it feeds on fungus or decaying plant material (Hoffman 
1990). The San Xavier talussnail is hermaphroditic (Morton 1968, 
Hoffman 1990). After a rain, the snail will lay eggs, feed, and mate. 
Fertilization and production of eggs takes several days. If the rains 
are short-lived, the eggs are held until the next rain. The species 
requires three or four years to mature, depending on rainfall 
frequency, and has a reproductive life of four to six years, depending 
on the total number of days it remains active (Hoffman 1990).
    Talussnails are extremely sensitive to desiccation and 
sedimentation resulting from disturbance of the talus and associated 
vegetation. In general, desert snails are known to protect themselves 
from drying out by crawling into deep, cool rockslides that are not 
filled with soil. The limestone rock or other talus that contains 
calcium carbonate is crucial to the species, as it aids in shell 
deposition and neutralizes carbonic acid that is produced during 
estivation (Hoffman 1990). The San Xavier talussnail is known to 
estivate for up to three years and in most years is only active for 
three or four days (Hoffman 1990).
    The San Xavier talussnail was included as a Category 2 species in 
the Service's May 22, 1984, notice of review of candidate invertebrates 
(49 FR 21664) and in the January 6, 1989, animal candidate notice of 
review (54 FR 554). Category 2 species are those for which the Service 
has some evidence of vulnerability, but for which there is insufficient 
scientific and commercial information to support proposed rules at the 
time. The San Xavier talussnail was included as a Category 1 species in 
the November 21, 1991, animal candidate notice of review (56 FR 58804). 
Category 1 species are those for which the Service has sufficient 
biological data to support proposals for listing.

Summary of Factors Affecting the Species

    Section 4 of the Endangered Species Act (16 U.S.C. 1531 et seq.) 
and regulations (50 CFR part 424) promulgated to implement the listing 
provisions of the Act set forth the procedures for adding species to 
the Federal lists. A species may be determined to be an endangered or 
threatened species due to one or more of the five factors described in 
section 4(a)(1). These factors and their application to the San Xavier 
talussnail (Sonorella eremita) are as follows:
    A. The present or threatened destruction, modification, or 
curtailment of its habitat or range. The San Xavier talussnail is a 
very restricted endemic and is extremely vulnerable to any disturbance 
that would remove talus, increase interstitial sedimentation, or 
otherwise alter moisture conditions in its habitat (e.g., road or trail 
expansion or alteration, mining exploration) (Hoffman 1990). Within the 
species' habitat are inactive mining prospects and mines, mining 
stakes, a powerline across the east ridge, and a road leading to a 
microwave site on the hilltop. A large copper mine is located nearby. 
There are housing developments of small acreage to the north and to the 
southwest of the hill. The habitat is too steep (30 to 40 percent 
slope) to permit house construction, but possible future threats 
include additional road construction, expansion of the copper mine and/
or tailings, and small-scale prospecting and mining.
    B. Overutilization for commercial, recreational, scientific, or 
educational purposes. The extremely restricted habitat of this species 
makes it vulnerable to excessive collecting during periods when the 
snails are active.
    C. Disease or predation. No diseases are known. Rodent predation is 
random and sporadic on the San Xavier talussnail (Hoffman 1990).
    D. The inadequacy of existing regulatory mechanisms. The State of 
Arizona offers no protection to this species. The Act would provide 
protection and encourage active management through ``Available 
Conservation Measures'' discussed below.
    E. Other natural or manmade factors affecting its continued 
existence. The very restricted range of the San Xavier talussnail makes 
it vulnerable to extinction from relatively small-scale human actions. 
The only known habitat for the species is on a single rockslide near 
Tucson, Arizona, in an area of limestone talus about 15 by 30 m (50 by 
100 ft) near a dirt road. The habitat is located downslope from a dirt 
road, making it vulnerable to infiltration of rocks and soil or other 
material. The species is so restricted in range that it is threatened 
by even limited removal of cover through vandalism or by individuals 
curious about the presence of a rare species. Removal of cover, 
including both rocks and vegetation, harms snails by exposing them to 
the drying effects of the sun and periods of low ambient humidity.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by this species in determining to propose this 
rule. Based on this evaluation, the preferred action is to list the San 
Xavier talussnail as endangered. The species has a highly restricted 
range, is located in an area of growing urban development and active 
mining, and is easily accessible by road. Although the San Xavier 
talussnail is on private land, Federal actions may occur as the area 
continues to develop. Endangered status is most appropriate because the 
single known population could be destroyed by one action. Because of 
the vulnerability of the population, threatened status does not appear 
appropriate for the San Xavier talussnail. A decision to take no action 
would exclude this species from needed protection available under the 
Act, and the species would likely decline. The decision not to propose 
critical habitat for the San Xavier talussnail is explained in the 
following section.

Critical Habitat

    Section 4(a)(3) of the Act, as amended, requires that, to the 
maximum extent prudent and determinable, the Secretary propose critical 
habitat at the time a species is proposed to be endangered or 
threatened. The Service finds that designation of critical habitat is 
not prudent for the San Xavier talussnail at this time.
    The extremely restricted habitat of the species makes it vulnerable 
to collection and isolated acts of vandalism. Although there are 
relatively few amateur collectors of land snails, a single collection 
effort under advantageous conditions could severely deplete the 
species' population. The population could, however, withstand some 
limited, regulated scientific collection. Of greater concern than 
collection is the potential for acts of vandalism that directly kill 
the snails by crushing or by habitat disturbances that cause 
desiccation of the snails. These acts may sometimes be purposeful, but 
may also be caused by well-intentioned persons who are curious about 
the presence of an endangered species. The likelihood of these 
potential threats occurring would be greatly increased by designation 
of critical habitat, because the publication of critical habitat maps 
and descriptions would allow unauthorized persons to precisely identify 
the locality of this species. Identification of critical habitat would 
therefore increase the degree of threat to this species.
    Critical habitat designation would also not provide additional 
benefit to the species. The range and major ecological requirements of 
this species are sufficiently known to provide adequate protection 
through the Act's take prohibitions and application of the section 7 
jeopardy standard. The Service will continue to communicate the 
conservation needs of the species to the involved landowner, as well as 
inform the landowner of the status of legal protection and conservation 
planning for the species.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing encourages and results in 
conservation actions by Federal, State, and private agencies, groups, 
and individuals. The Act provides for possible land acquisition and 
cooperation with the States and requires that recovery actions be 
carried out for all listed species. The protection required of Federal 
agencies and the prohibitions against taking and harm are discussed, in 
part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(4) requires Federal agencies to confer with the 
Service on any action that is likely to jeopardize the continued 
existence of a species proposed for listing or result in destruction or 
adverse modification of proposed critical habitat. If a species is 
listed subsequently, section 7(a)(2) requires Federal agencies to 
ensure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of such a species or to 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into formal consultation with the Service. 
Potential Federal activities that may require consultation under 
section 7 include permits for road and transmission facilities near the 
locality of the San Xavier talussnail.
    The Act and implementing regulations found at 50 CFR 17.21 set 
forth a series of general prohibitions and exceptions that apply to all 
endangered wildlife. These prohibitions, in part, make it illegal for 
any person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect; or to attempt any of these), import or export, 
ship in interstate commerce in the course of commercial activity, or 
sell or offer for sale in interstate or foreign commerce any listed 
species. It also is illegal to possess, sell, deliver, carry, 
transport, or ship any such wildlife that has been taken illegally. 
Certain exceptions apply to agents of the Service and State 
conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered wildlife species under certain circumstances. 
Regulations governing permits are codified at 50 CFR 17.22. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, and/or for incidental take in 
the course of otherwise lawful activities.
    Requests for copies of the regulations regarding listed wildlife 
and inquiries regarding prohibitions and permits may be addressed to 
the Office of Management Authority, U.S. Fish and Wildlife Service, 
room 420C, 4401 N. Fairfax Drive, Arlington, Virginia 22203 (703/358-
2104; FAX 703/358-2281).

Public Comments Solicited

    The Service intends that any final action resulting from this 
proposal will be as accurate and as effective as possible. Therefore, 
comments or suggestions from the public, other concerned governmental 
agencies, the scientific community, industry, or any other interested 
party concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threat (or lack thereof) to the San Xavier talussnail;
    (2) The location of any additional populations of this species and 
the reasons why any habitat should or should not be determined to be 
critical habitat as provided by section 4 of the Act;
    (3) Additional information concerning the range, distribution, and 
population size of this species; and
    (4) Current or planned activities in the subject area and their 
possible impacts on this species.
    Final promulgation of the regulation on this species will take into 
consideration the comments and any additional information received by 
the Service, and such communications may lead to a final regulation 
that differs from this proposal.
    The Endangered Species Act provides for one or more public hearings 
on this proposal, if requested. Requests must be received within 45 
days of the date of publication of the proposal in the Federal 
Register. Such requests must be made in writing and addressed to 
Arizona Ecological Services Office (see ADDRESSES section).

National Environmental Policy Act

    The Fish and Wildlife Service has determined that Environmental 
Assessments and Environmental Impact Statements, as defined under the 
authority of the National Environmental Policy Act of 1969, need not be 
prepared in connection with regulations adopted pursuant to section 
4(a) of the Endangered Species Act of 1973, as amended. A notice 
outlining the Service's reasons for this determination was published in 
the Federal Register on October 25, 1983 (48 FR 49244).

References Cited

Hoffman, J.E. 1990. Status survey of seven land snails in the 
Mineral Hills and the Pinaleno Mountains, Arizona. Prepared for U.S. 
Fish and Wildlife Service, Phoenix, Arizona. Contract Number: 20181-
88-00973.
Morton, J.E. 1968. Molluscs. Hutchinson University Library. London. 
244 pp.
Pilsbry, H.A., and J.A. Ferriss. 1915. Mollusca of the southwestern 
states. VII. The Dragoon, Mule, Santa Rita, Baboquivari and Tucson 
ranges, Arizona. Proc. Acad. Nat. Sci. Phila. 67:363-418; Plates 8-
15.

Authors

    The primary authors of this proposed rule are Debra T. Bills, 
Arizona Ecological Services Field Office (see ADDRESSES section), 
and Dr. Steven M. Chambers, Division of Endangered Species, U.S. 
Fish and Wildlife Service, P.O. Box 1306, Albuquerque, New Mexico 
87123 (505/766-3972).

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

    Accordingly, the Service hereby proposes to amend part 17, 
subchapter B of chapter I, title 50 of the Code of Federal Regulations, 
as set forth below:

PART 17--[AMENDED]

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

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

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under ``SNAILS,'' to the List of Endangered and 
Threatened Wildlife to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * * 

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             Species                                 Vertebrate                                                 
----------------------------------                   population                                                 
                                                       where                 When listed    Critical    Special 
                  Scientific name  Historic range    endangered    Status                   habitat      rules  
  Common name                                            or                                                     
                                                    threatened                                                  
----------------------------------------------------------------------------------------------------------------
                                                                                                                
                                                  * * * * * * *                                                 
     Snails                                                                                                     
                                                                                                                
                                                                                                                
                                                  * * * * * * *                                                 
Talussnail, San   Sonorella        U.S.A. (AZ)....           NA  E           ...........           NA         NA
 Xavier.           eremita.                                                                                     
                                                                                                                
                                                  * * * * * * *                                                 
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    Dated: March 14, 1994.
Mollie H. Beattie,
Director, Fish and Wildlife Service.
[FR Doc. 94-6791 Filed 3-22-94; 8:45 am]
BILLING CODE 4310-55-P