DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service


Endangered and Threatened Wildlife and Plants; 90-Day Finding on
Petition To Delist Astragalus magdalenae var. peirsonii (Peirson's
milk-vetch)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service, make a 90-day
finding for a petition to remove Astragalus magdalenae var. peirsonii
(Peirson's milk-vetch) from the Federal List of Threatened and
Endangered Wildlife and Plants pursuant to the Endangered Species Act
(ESA) (16 U.S.C. 1531 et seq.). We find that the petition presents
substantial information indicating that delisting this plant may be
warranted. We are initiating a status review to determine if
delisting this species is warranted.

DATES: This finding was made on August 29, 2003. To be considered in
the 12-month finding on this petition, comments and information
should be submitted to us by November 4, 2003.

ADDRESSES: Comments, material, information, or questions concerning
this petition and finding should be sent to the Field Supervisor,
Carlsbad Fish and Wildlife Office, U.S. Fish and Wildlife Service,
6010 Hidden Valley Road, Carlsbad, CA 92009. The petition and
supporting information are available for public inspection by
appointment during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor,
Carlsbad Fish and Wildlife Office, at the above address (telephone:
760-431-9440).

SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(A) of the Endangered Species Act of 1973 (ESA)
(16 U.S.C. 1531 et seq.) requires that we make a finding on whether a
petition to list, delist, or reclassify a species presents
substantial scientific or commercial information indicating that the
petitioned action may be warranted. To the maximum extent
practicable, this finding is to be made within 90 days of receipt of
the petition, and the finding is to be published promptly in the
Federal Register. If we find substantial information present, we are
required to promptly commence a review of the status of the species
(50 CFR 424.14). ``Substantial information'' is defined in 50 CFR
424.14(b) as ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the
petition may be warranted.'' Petitioners need not prove that the
petitioned action is warranted to support a ``substantial'' finding;
instead, the key consideration in evaluating a petition for
substantiality involves demonstration of the reliability and adequacy
of the information supporting the action advocated by the petition.
On October 25, 2001, we received a petition to delist Astragalus
magdalenae var. peirsonii (Peirson's milk-vetch) dated October 24,
2001, from David P. Hubbard, Ted J. Griswold, and Philip J. Giacinti,
Jr. of Procopio, Cory, Hargreaves & Savitch, LLP, that was prepared
for the American Sand Association (ASA), the San Diego Off-Road
Coalition, and the Off-Road Business Association (ASA et al. 2001).
Various supporting documents were submitted with the petition. The
petition (ASA et al. 2001) asserts that the original decision to list
A. magdalenae var. peirsonii was in error, and claims that: (1) The
original listing decision was made without an actual plant count; (2)
the original listing relied on data developed prior to the
implementation of the California Desert Protection Act (CDPA); (3)
the original listing decision relied on field studies that the Bureau
of Land Management (BLM) has since determined were biased and
scientifically unsound; (4) monitoring studies indicate that A.
magdalenae var. peirsonii is abundant and thriving; and (5) plant
counts confirm that the Imperial Sand Dunes support more than 100,000
A. magdalenae var. peirsonii individuals and a healthy seed bank.
On November 6, 2002 we received a 60-day notice of intent to sue
from David P. Hubbard et al., representing the ASA et al, citing our
alleged failure to make the findings on this petition as required by
the ESA. A complaint was executed in the United States District Court
for the Southern District of California on February 25, 2003. The
plaintiffs (ASA et al.) challenge the Service's failure to make both
the 90-day finding and 12-month finding on petition to delist the
Peirsons's milk-vetch. In August 2003, the Department of Justice
entered into a settlement agreement with ASA et al., requiring us to
make a 90-day finding on this petition by August 29, 2003, and, if
the 90-day finding is that the petition contains substantial
information that delisting Astragalus magdalenae var. peirsonii may
be warranted, a 12-month finding by May 31, 2004. As part of this
settlement agreement, the petitioners asked that we also accept and
consider the information provided in Phillips and Kennedy (2002) when
making our findings.
The factors for listing, delisting, or reclassifying species are
described at 50 CFR 424.11. We may delist a species only if the best
scientific and commercial data available substantiate that it is
neither endangered nor threatened. Delisting may be warranted as a
result of: (1) Extinction, (2) recovery, or (3) a determination that
the original data used for classification of the species as
endangered or threatened were in error.

Biology and Distribution

Astragalus magdalenae var. peirsonii occurs essentially as one
population of scattered colonies within the Algodones Dunes in the
Sonoran Desert of Imperial County, California. The Algodones Dunes
are often called the Imperial Sand Dunes, a designation derived from
a land use area called the Imperial Sand Dunes Recreation Area
established by BLM. The habitat for A. magdalenae var. peirsonii is
slopes and hollows of wind-blown desert dunes, chiefly along a
northwest-to-southeast orientation on the BLM-managed land. The
distribution and relative abundance of the plant varies from place to
place and year to year (WESTEC Services, Inc. (WESTEC) 1977;
Willoughby 2000, 2001; Thomas Olsen Associates, Inc. (TOA) 2001;
Phillips and Kennedy 2002). The tendency of plants to be found in
patches is likely due to the localized dispersal of the fruits and
seeds, as well as dune morphology and differences in local rainfall
patterns.
Astragalus magdalenae var. peirsonii (Peirson's milk-vetch) is an
erect to spreading, short-lived perennial in the Fabaceae (Pea
family) (Barneby 1959, 1964). Plants may reach 20 to 70 centimeters
(cm) (8 to 27 inches (in)) in height and develop taproots (Barneby
1964) that penetrate to the deeper, more moist sand. The stems and
leaves are covered with fine, silky appressed (flat on surface)
hairs. The small, narrow, widely spaced leaflets may fall off in
response to drought. The purple flowers are arranged in 10-to
17-flowered axillary racemes. Individuals are reportedly able to
flower in their first growing season (Barneby 1964; Romspert and Burk
1979). Romspert and Burk (1979) found inflorescences present from
December through at least April. The fruits are 2 to 3.5 cm (0.8 to
1.4 in) long and inflated. Phillips and Kennedy (2002) determined
that the mean number of fruits per older plant was 171.5 compared
with an estimated 5 fruits per plant for plants said to be in their
first year. The seeds, among the largest known for any species of
Astragalus (Bowers 1996), average 15 milligrams (mg) (less than 0.1
ounces (oz)) each in weight and are up to 4.7 millimeters (mm) (0.2
in) in length. There are 11 to 16 seeds per fruit (Barneby 1964).
Astragalus lentiginosus var. borreganus, easily distinguished by its
conspicuously broad leaflets, is the only similar taxon in the area.
Seeds are dispersed by three basic mechanisms: (1) Falling from
partially open fruits that remain on the plant; (2) falling from
fruits that are blown across the sand; or (3) falling to the ground
within the fruit (Barneby 1964; Bowers 1986; Phillips and Kennedy
2002). Wind dispersal of fruits across the surface of the dunes is
likely the primary long-distance dispersal method for this plant. The
fruits and seeds tend to accumulate on the leeward side of the dunes.
These seeds may be found scattered on the sand surface at times.
The number and location of standing plants may vary considerably
from year to year due to a number of factors, including the amount,
timing, and location of rainfall; temperature; soil conditions; and
the extent and nature of the seed bank. For example, along the BLM
transects, Willoughby (2001) reported that 942 plants were found in
1999 and only 86 plants in 2000, both low rainfall years compared to
the wetter year 1998, when 5,064 plants were found. In 2001, 71,926
plants were reported (TOA 2001), but this single census does not
provide any information on population trend. Plant mortality over the
short term may also be considerable (Phillips and Kennedy 2002).
In 1979, Astragalus magdalenae var. peirsonii was listed by the
State of California as an endangered species under the California
Endangered Species Act (CESA). On October 6, 1998, we listed A.
magdalenae var. peirsonii as threatened (63 FR 53596). We made this
determination based upon the best scientific and commercial
information available at the time. As stated and documented in the
final listing rule, this action was taken, in part, because of
threats of increasing habitat loss from off-highway vehicle (OHV)
use, associated recreational development, destruction of plants, and
lack of protections afforded the plant on Federal lands. We did not
designate critical habitat for A. magdalenae var. peirsonii at the
time of listing because such action was not considered prudent at
that time.

Finding

We have reviewed the petition and literature cited in and
provided with the petition and considered it with other information
in our files. We have found that the petition presents substantial
information indicating that delisting Astragalus magdalenae var.
peirsonii may be warranted. The petitioners have suggested that A.
magdalenae var. peirsonii is a species that exists, in many years,
largely as a seed bank, with relatively few standing individuals
above ground. At the time we listed A. magdalenae var. peirsonii as a
threatened species (63 FR 53596), we did not have--and so could not
consider--information about the extent of the seed bank of this
species. Petitioners have provided information suggesting the species
may have a healthy seed bank (Phillips and Kennedy 2002), even though
standing plants are frequently rare. Surveys conducted since we
listed this species in 1998 indicate that, in some years, probably in
response to increased precipitation, the number of standing plants
considerably increases (TOA 2001; Willoughby 2000, 2001). While
significant questions remain about the extent and viability of the
seed bank, and the contribution of the increased numbers of standing
plants in 1998 (Willoughby 2000) and 2001 (TOA 2001) to the seed bank
and the persistence of this species into the future, we consider
these to be issues relevant to the listing determination and
warranting further investigation. Accordingly, we believe it is
appropriate to consider this information, and any other new
information available about this species and the threats it may face,
in a status review.

Public Information Solicited

When we make a finding that substantial information exists to
indicate that listing or delisting a species may be warranted, we are
required to promptly commence a review of the status of the species.
To ensure that the status review is complete and based on the best
available scientific and commercial information, we are soliciting
information on Astragalus magdalenae var. peirsonii. This includes
information regarding historical and current distribution, biology
and ecology, ongoing conservation measures for the species and its
habitat, and threats to the species and its habitat. We also request
information regarding the adequacy of existing regulatory mechanisms.
We request any additional information, comments, and suggestions from
the public, other concerned governmental agencies, Tribes, the
scientific community, industry or environmental entities, or any
other interested parties concerning the status of A. magdalenae var.
peirsonii.
If you wish to comment, you may submit your comments and
materials concerning this finding to the Field Supervisor, Carlsbad
Fish and Wildlife Office (see ADDRESSES section). Our practice is to
make comments, including names and home addresses of respondents,
available for public review during regular business hours.
Respondents may request that we withhold a respondent's identity, as
allowable by law. If you wish us to withhold your name or address,
you must state this request prominently at the beginning of your
comment. However, we will not consider anonymous comments. To the
extent consistent with applicable law, we will make all submissions
from organizations or businesses, and from individuals identifying
themselves as representatives or officials of organizations or
businesses, available for public inspection in their entirety.
Comments and materials received will be available for public
inspection, by appointment, during normal business hours at the above
address.

References Cited

A complete list of all references cited in this finding is
available, upon request, from the Carlsbad Fish and Wildlife Office
(see ADDRESSES section).

Authority

The authority for this action is section 4 of the Endangered
Species Act of 1973 (16 U.S.C. 1531 et seq.).

Dated: August 29, 2003.
Steve Williams, Director, Fish and Wildlife Service.
[FR Doc. 03-22600 Filed 9-4-03; 8:45 am]