[Federal Register Volume 63, Number 193 (Tuesday, October 6, 1998)]
[Proposed Rules]
[Pages 53620-53623]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26737]
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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; Withdrawal of
Proposed Rule to List the San Xavier Talussnail (Sonorella eremita) as
Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; withdrawal.
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SUMMARY: The Fish and Wildlife Service (Service) withdraws a proposal
to list the San Xavier talussnail (Sonorella eremita) as an endangered
species under the Endangered Species Act of 1973, as amended. This
species occurs on a hillside on private property in Pima County,
Arizona. Following publication of the proposed rule, the Service
gathered additional information on land ownership, and a conservation
agreement was completed which reduces threats to the species to a level
at which listing as threatened or endangered is not warranted.
ADDRESSES: The complete file for this rule is available for inspection,
by appointment, during normal business hours at the Arizona Ecological
Services Field Office, 2321 W. Royal Palm Road, Suite 103, Phoenix,
Arizona 85021.
FOR FURTHER INFORMATION CONTACT: Debra Bills at the above address or
telephone 602/640-2720.
SUPPLEMENTARY INFORMATION:
Background
The San Xavier talussnail (Sonorella eremita) is a land snail and
was first described in 1910 by H.A. Pilsbry and L.E. Daniels (Pilsbry
and Ferriss 1915). The species has a globose (globular) 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. 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. The 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 (has both male and
female reproductive organs) (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 snails
hold the eggs until the next rain. The species requires 3 or 4 years to
mature, depending on rainfall frequency, and has a reproductive life of
4 to 6 years, depending on the number of days it remains active
(Hoffman 1990).
Talussnails are sensitive to drying and sedimentation resulting
from disturbance of the talus slope and associated vegetation. In
general, desert snails are known to protect themselves from drying 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 (period of inactivity)
(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).
With the assistance of global positioning system units in February,
1998, the Service and the Arizona Game and Fish Department were able to
obtain the exact location of the talus slope and identify the correct
landowner. Discussions with this landowner led to a revised assessment
of the threats faced by the San Xavier talussnail and the talus slope
on which it resides.
Previous Federal Action
We included the San Xavier talussnail as a Category 2 candidate
species in our May 22, 1984, notice of review of candidate
invertebrates (49 FR 21664) and in our January 6, 1989, animal
candidate Notice of Review (54 FR 554). Category 2 species were those
taxa for which we had information indicating that listing may be
warranted but for which the information was insufficient to support
issuance of proposed listing rules. We included the San Xavier
talussnail as a Category 1 candidate species in our November 21, 1991,
animal candidate notice of review (56 FR 58804). Category 1 species
were those taxa for which we had sufficient information to support
issuance of listing proposals. We published a proposal to list this
species in the Federal Register on March 23, 1994 (59 FR 21664).
Publication of the proposal initiated a comment period which expired on
May 23, 1994.
Processing of a final determination on the proposed rule to list
the San Xavier
[[Page 53621]]
talussnail was delayed by the moratorium on final listings imposed on
April 10, 1995 (Public Law 104-6). Following lifting of the moratorium
and restoration of significant funding for listing through passage of
the Omnibus Budget Reconciliation Law on April 26, 1996, we developed
listing priority guidance (May 16, 1996, 61 FR 24722) to clarify the
order in which we would process rulemakings. We commenced work on
resolving outstanding proposed listings in accordance with this listing
priority guidance and following revised guidances (December 5, 1996, 61
FR 64475; October 23, 1997, 62 FR 55268; May 8, 1998, 63 FR 25502).
Processing of this withdrawal conforms with our current listing
priority guidance for Fiscal Years 1998 and 1999, published on May 8,
1998 (63 FR 25502). The guidance gives highest priority (Tier 1) to
processing emergency rules to add species to the Lists of Endangered
and Threatened Wildlife and Plants (Lists); second priority (Tier 2) to
processing final determinations on proposals to add species to the
Lists, processing new proposals to add species to the Lists, processing
administrative findings on petitions (to add species to the Lists,
delist species, or reclassify listed species), and processing a limited
number of proposed or final rules to delist or reclassify species; and
third priority (Tier 3) to processing proposed or final rules
designating critical habitat. Processing of this withdrawal is a Tier 2
action.
Because of the new information on landowner status, and in
consideration of the length of time that had elapsed since issuance of
the proposal on March 23, 1994, and expiration of the initial comment
period on May 23, 1994, we opened a second public comment period from
May 22, 1998, to July 21, 1998 (63 FR 28343). We sought comments or
suggestions from the public, other concerned governmental agencies, the
scientific community, industry, and other interested parties. We
requested new information that may have developed in the intervening
period since the proposal was first published and that would expand the
current knowledge concerning the status, distribution, or security of
the San Xavier talussnail or any factor affecting the species or its
habitat. During this public comment period, discussions with the
landowner led to the development of a draft conservation agreement for
the species and its habitat. We then published another notice in the
Federal Register on June 23, 1998 (63 FR 34142), announcing the
availability of this draft conservation agreement for review and
comment. We accepted comments on the draft conservation agreement until
the July 21, 1998, closing of the second public comment period.
The parties to the conservation agreement, the Service, the Arizona
Game and Fish Department, El Paso Natural Gas Company (EPNG), and the
Arizona Electric Power Cooperative, Inc. (AEPCO), finalized and signed
the conservation agreement on September 23 and 24, 1998. The
conservation agreement provides the following protective measures:
1. An Advisory Committee will be established, consisting of a
representative of each party to the conservation agreement, to evaluate
the results of implementation of the conservation agreement and make
recommendations for revisions.
2. The area encompassing and adjacent to the habitat of the snail
(the ``Area of Concern'') will not be modified.
3. The Advisory Committee will agree upon and mark the corners of
the Area of Concern and will include the area that drains into the
talus slope.
4. Rock, soil, or construction material will not be placed in the
Area of Concern.
5. The dirt road above the Area of Concern will not be widened.
6. Routine road maintenance will be conducted so as not to change
the hydrology of the Area of Conern.
7. Herbicides will not be applied near the Area of Concern.
8. EPNG or AEPCO will notify the other parties to the agreement and
take precautions when working on microwave facilities on the hilltop.
9. The Advisory Committee will review all plans for change in
management and ensure sufficient mitigation measures are provided to
maintain protection for the species.
Public Comments
In the March 23, 1994, proposed rule (59 FR 21664) and the
associated notifications, we asked all interested parties to submit
factual reports or information that might contribute to development of
a final rule. We contacted appropriate State agencies and
representatives, scientific organizations, and other interested parties
and requested comments. We published newspaper notices for the proposed
listing and comment period, and the reopening of the public comment
period in the Tucson Citizen and the Arizona Daily Star.
The proposed rule to list this species pre-dated our policy to seek
independent peer review of listing actions (59 FR 34270, published July
1, 1994). However, during the open comment periods, we solicited the
expert opinions of appropriate independent specialists regarding
pertinent scientific or commercial data relating to the taxonomy and
ecology of the San Xavier talussnail. However, we did not receive any
responses from the reviewers.
In the following summary, we address the comments received during
the two comment periods that indicate opposition to withdrawing the
proposed rule. We grouped comments of a similar nature into one of nine
general issues.
Issue 1: One commenter questioned what type of land use
restrictions and enforcement actions might result from enactment of the
conservation agreement.
Service Response: Because the current landowners have no plans to
develop the habitat of the San Xavier talussnail, agreeing to protect
the site by entering into the conservation agreement did not restrict
any current or planned land use of the site. If the conservation
agreement is not implemented, and if threats to the species are not
addressed through other means, we will consider reinitiating the
listing process for the species.
Issue 2: Certain threats to the San Xavier talussnail identified in
the proposed rule, including new mining, expansion of a nearby large
copper mine, use of herbicides, vandalism, excessive collection, and
predation, continue to threaten the species.
Service Response: As described in detail in the ``Summary of
Factors Affecting the Species'' section of this notice, we believe that
new information, including protection offered by the conservation
agreement, indicates that the threats to the San Xavier talussnail
described in the proposed rule are substantially reduced.
During the past public comment period, we discovered that EPNG,
which owns the talus slope and is a signatory to the conservation
agreement, also owns all mining claims on the talus slope. The large
mine nearby currently has no plan to expand in the area of the talus
slope.
AEPCO, which owns a microwave facility at the top of the hill and
maintains the road, has never applied herbicides to the road or
anywhere near the talus slope. Although herbicides may be used upslope
at the microwave facility, the application is confined to the microwave
facility fenced area and consists of annual pre-emergent application
between November and March. We have not documented any instances of
adverse effects to the San Xavier talussnail from herbicide
[[Page 53622]]
application, and we do not anticipate any effects in the future.
The parties to the conservation agreement recognize the potential
threat to the San Xavier talussnail from vandalism and excessive
collection. Because both AEPCO and EPNG are also concerned about
vandalism of the microwave facility, access to the site is restricted.
The parties to the conservation agreement are evaluating the need for
fencing, and replacing or adding ``No Trespassing'' signs at the site,
particularly in areas used by dirt bikes.
Rodent predation is random and sporadic on the San Xavier
talussnail (Hoffman 1990). We have no information indicating that
rodent predation is above natural levels or that it poses a significant
threat to the species.
Issue 3: Infiltration of sediment from the dirt road passing near
the talus slope may continue to threaten the San Xavier talussnail.
Service Response: Access to the road is restricted by a locked
gate. AEPCO's use of the road is primarily by microwave technicians who
visit the microwave facility once every other month. An equipment
problem may require daily visits until remedied, but this is rare.
Information provided by AEPCO shows that since the construction of the
road in 1978, maintenance has been conducted on the road on six
occasions. The last time a grader worked the entire road was December
1990. We have not documented any adverse effects to the San Xavier
talussnail resulting from past road maintenance.
As specified in the conservation agreement, AEPCO will coordinate
future road maintenance with the Advisory Committee and will not
conduct maintenance during the talussnail's active period except in
emergencies. We believe these precautions adequately protect the
species from road maintenance.
Issue 4: The 5-year time frame mentioned in the draft conservation
agreement is insufficient to protect the talussnail.
Service Response: Although the draft conservation agreement
specified a duration of five years with the possibility to be extended
another five years, the final conservation agreement specifies a
duration of ten years. In addition, the parties to the conservation
agreement have committed to an annual review to ensure protection is
sufficient. If, after the conservation agreement expires, threats to
the species are not addressed by renewal of the conservation agreement
or other means, we will evaluate the status of the species and consider
reinitiating the listing process.
Issue 5: Because the San Xavier talussnail occurs only at a single,
small site, a single catastrophic event could be devastating for the
species.
Service Response: As far as we know, the talussnail has always been
limited to this single, small site. Because the species has persisted
under these natural conditions, we do not believe that natural
catastrophic events pose a significant threat to the species. The
potential human-caused catastrophic events include significant
disturbance to the talus slope or upslope areas. We believe that the
measures specified in the conservation agreement sufficiently reduce
the likelihood that such human-caused catastrophic events will occur.
Issue 6: Vandalism and excessive collection remain a threat because
the talus slope can be accessed easily from the bottom.
Service Response: Although no physical barriers exist to absolutely
prevent access to the site, we believe that the conservation agreement
adequately addresses the threats of vandalism and overcollection. The
species is located on private land, and trespassing is prohibited. The
parties to the agreement are evaluating the need for fencing or
additional ``No Trespassing'' signs to further discourage trespassing.
In addition, anyone collecting San Xavier talussnails or otherwise
taking them would be guilty of violating State of Arizona wildlife
regulations (see factor D of the ``Summary of Factors Affecting the
Species'' section).
Issue 7: Emergency road work or other emergencies, which the
conservation agreement exempts from review and approval by the Advisory
Committee, poses a threat to the San Xavier talussnail.
Service Response: Major damage to the microwave tower, tower
equipment, or control building resulting from fire, vandalism, or
extreme weather conditions are considered emergencies requiring
immediate repairs. Also, damage to the road causing it to be impassable
would also be considered an emergency requiring immediate repairs.
Routine maintenance to these facilities is not considered an emergency.
AEPCO and EPNG have agreed to notify the other parties to the
conservation agreement as soon as practicable after discovery of an
emergency situation.
Issue 8: One commenter questioned the reference to ``reasonable
precautions'' in the conservation agreement to prevent rock, soil, or
construction material from being transported to the talus slope.
Service Response: Possible changes at the microwave site include
construction of an additional tower, a larger control building, and
additional fences. All of these activities have the potential to result
in material being transported to the talus slope. In accordance with
the conservation agreement, the Advisory Committee will review all
plans for change and recommend mitigation measures. Mitigation measures
could include removing excess materials and establishing temporary
barriers, silt fences, or hay bales downhill from the construction
area.
Issue 9: The ``No Surprises'' clause in the draft conservation
agreement shows the inadequacy of existing regulatory mechanisms to
protect the San Xavier talussnail.
Service Response: All references to ``No Surprises'' assurances
have been omitted in the final conservation agreement.
Summary of Factors Affecting the Species
Section 4 of the Act 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. We may determine a species 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 our decision to withdraw the proposal to list the San
Xavier talussnail 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 species and
is vulnerable to any disturbance that would remove talus, increase
interstitial (the spaces between the talus) sedimentation, or otherwise
alter moisture conditions (e.g., road or trail expansion or alteration,
mining exploration) (Hoffman 1990). We believe that new information
received since the publication of the proposed rule, and the
protections provided by the recently finalized conservation agreement,
indicate that threats to the species' habitat are not as great as
supposed or have been substantially reduced through adoption of the
conservation agreement.
A large, active copper mine, as well as inactive mining prospects
and mines, are located in the vicinity of the talus slope. During the
past public comment period, we discovered that EPNG, which owns the
talus slope and is a signatory to the conservation agreement, also
[[Page 53623]]
owns all mining claims on the talus slope. The large copper mine
currently has no plan to expand in the area of the talus slope.
There are housing developments of small acreages to the north and
to the southwest of the hill. However, the talus slope is too steep (30
to 40 percent slope) to permit housing construction.
A road leading to a microwave site on the hilltop passes near the
talus slope. This road receives very little traffic; microwave
technicians may visit the site once every other month, unless there is
a problem on the ground which may require more frequent visits. Access
to the road by the public is restricted by a locked gate. Information
provided by AEPCO shows that since the construction of the road in
1978, maintenance has been conducted on the road on six occasions. The
last time a grader worked the entire road was December 1990. We have
not documented any adverse effects to the San Xavier talussnail
resulting from past road maintenance. The conservation agreement
specifies that future road maintenance will be coordinated with the
Advisory Committee and will not occur during the talussnail's active
period except in emergencies. We believe these precautions adequately
protect the species from road maintenance.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Although we do not have any information indicating that any
significant collection of the San Xavier talussnail is occurring, the
extremely restricted distribution of the species makes it vulnerable to
overcollection during periods when the snails are active. Trespassing
on the talus slope is prohibited, vehicle access to the site is
restricted by a locked gate, and collection of the species is
prohibited by Arizona State law (see factor D). Also, additional
measures are being evaluated to further discourage trespassing and
collection. For these reasons, we believe that the potential threat of
overcollection of the species is small and not significant enough to
warrant listing the species at this time.
C. Disease or Predation
We do not know of any diseases affecting the San Xavier talussnail.
Rodent predation is random and sporadic on the species (Hoffman 1990).
However, we do not have any evidence indicating that rodent predation
is or may be a limiting factor for this species.
D. The Inadequacy of Existing Regulatory Mechanisms
The State of Arizona has placed the San Xavier talussnail on the
1998 Crustaceans and Mollusks Commission Order 42 and the list of
sensitive elements that qualify for Heritage funding. This designation
makes it illegal to collect or possess the species. The species occurs
on private land, and trespassing is prohibited. In addition, the
conservation agreement provides a framework for continued protection
and management of the San Xavier talussnail and its habitat. We believe
these provisions are adequate for the conservation of the species.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
The very restricted range of the San Xavier talussnail makes it
vulnerable to catastrophic events. As far as we know, the talussnail
has always been limited to the single, small site where it currently
exists. Because the species has persisted under these natural
conditions, we do not believe that natural catastrophic events pose a
significant threat to the species. Potential human-caused catastrophic
events include significant disturbance, including vandalism, to the
talus slope or upslope areas. We believe that the measures specified in
the conservation agreement addressing construction activities, road
maintenance, and trespassing sufficiently reduce the likelihood that
such human-caused catastrophic events will occur.
Finding and Withdrawal
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the San Xavier talussnail. Population trend information is
unavailable, but the species' habitat is secure. We no longer believe
that the San Xavier talussnail is in danger of extinction throughout
all or a significant portion of its range or is likely to become so in
the foreseeable future. We therefore withdraw the proposed rule to list
the San Xavier talussnail under the Endangered Species Act.
We will work to gather additional information on the status and
ecology of the San Xavier talussnail. Also, we will participate with
parties to the conservation agreement to ensure the long-term survival
of this species. If new information becomes available indicating the
presence of a new threat to the San Xavier talussnail or an increase in
the severity of a threat, and if the threats are not adequately
addressed through revision of the conservation agreement or other
means, we will consider reinitiating the listing process for the
species.
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; Pls. 8-15.
Author: The primary author of this document is Debra Bills, Arizona
Ecological Services Field Office (see ADDRESSES section).
Authority: The authority for this action is section
4(b)(6)(B)(ii) of the Endangered Species Act of 1973, as amended (16
U.S.C. 1531 et seq.).
Dated: September 29, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 98-26737 Filed 10-5-98; 8:45 am]
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