[Federal Register Volume 60, Number 63 (Monday, April 3, 1995)]
[Proposed Rules]
[Pages 16836-16847]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-8176]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AD11
Endangered and Threatened Wildlife and Plants: Proposal To
Determine Endangered Status for Three Wetland Species Found in Southern
Arizona and Northern Sonora
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule and notice of petition findings.
-----------------------------------------------------------------------
SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes
endangered status pursuant to the Endangered Species Act (Act) of 1973,
as amended, for two plants, Spiranthes delitescens (Canelo Hills
ladies'-tresses) and Lilaeopsis schaffneriana spp. recurva (Huachuca
water umbel), and one amphibian, the Sonora tiger salamander (Ambystoma
tigrinum stebbinsi). These species occur in a limited number of wetland
habitats in southern Arizona and northern Sonora, Mexico. They are
threatened by one or more of the following--collecting, disease,
predation, competition with nonnative species, catastrophic floods,
drought, and degradation and destruction of [[Page 16837]] habitat
resulting from livestock overgrazing, water diversions, dredging, and
groundwater pumping. All three taxa are also threatened with stochastic
extirpations or extinction due to small numbers of populations or
individuals. This proposed rule, if made final, would extend the Act's
protection to these three taxa.
DATES: Comments from all interested parties must be received by June 2,
1995. Public hearing requests must be received by May 18, 1995.
ADDRESSES: Comments and materials should be sent to the Arizona
Ecological Services State 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:
Jim Rorabaugh at the above address (telephone 602/640-2720: facsimile
602/379-6629).
SUPPLEMENTARY INFORMATION:
Background
Cienegas are mid-elevation wetland communities often surrounded by
relatively arid environments. They are typically associated with
permanent perennial springs and stream headwaters, have permanently or
seasonally saturated highly organic soils, and have a low probability
of flooding or scouring (Hendrickson and Minckley 1984). Cienegas
support diverse assemblages of animals and plants, including many
species of limited distribution, such as the three taxa in this
proposed rule (Hendrickson and Minckley 1984, Lowe 1985, Minckley and
Brown 1982, Ohmart and Anderson 1982). Although Spiranthes delitescens
(Spiranthes), Lilaeopsis schaffneriana spp. recurva (Lilaeopsis), and
Sonora tiger salamander typically occupy different microhabitats, they
all occur in cienegas: Lilaeopsis also occurs along streams and rivers.
Cienegas and perennial streams and rivers in the desert southwest
are extremely rare. The Arizona Game and Fish Department (1993)
recently estimated that riparian vegetation associated with perennial
streams comprises about 0.4 percent of the total Arizona land area,
with present riparian areas being remnants of what once existed. The
State of Arizona (1990) estimates that up to 90 percent of the riparian
habitat along Arizona's major desert watercourses has been lost,
degraded, or altered in historic times. Spiranthes, Lilaeopsis, and the
Sonora tiger salamander occupy small portions of these rare habitats.
Spiranthes delitescens (Canelo Hills ladies'-tresses). Spiranthes
delitescens is a slender, erect, terrestrial orchid that when in bloom
reaches approximately 50 centimeters (cm) 20 inches (in)) tall. Five to
ten, linear-lanceolate, grass-like leaves, 18 cm (7.1 in) long and 1.5
cm (0.6 in) wide, grow basally on the stem. The fleshy swollen roots
are approximately 5 millimeters (mm) (0.2 in) in diameter. The top of
the flower stalk contains up to 40 small white flowers arranged in a
spiral. The species is presumed to be perennial, but mature plants
rarely flower in consecutive years and in some years have no visible
aboveground structures (McClaren and Sundt 1992, Newman 1991).
P.S. Martin first collected Spiranthes delitescens in 1968 at a
site in Santa Cruz County, Arizona (Sheviak 1990). This specimen was
first identified as Spiranthes graminea, a related Mexican species.
Sheviak (1990) found that the Spiranthes in Arizona, previously thought
to be S. graminea, displayed a distinct set of morphological and
cytological characteristics and named them S. delitescens.
This species is known from four cienegas at about 1,525 meters (m)
(5,000 feet (ft)) elevation in the San Pedro River watershed in Santa
Cruz and Cochise Counties, southern Arizona (Newman 1991). The total
amount of occupied habitat is less than 81 hectares (ha) (200 acres
(ac)). All populations are on private land less than 37 kilometers (km)
(23 miles (mi)) north of the U.S./Mexico border.
Potential habitat in Sonora, Mexico, has been surveyed, but no
Spiranthes populations have been found.
The dominant vegetation associated with Spiranthes includes
grasses. Carex spp. (sedges), Juncus spp. (rushes), Eleocharis spp.
(spike rushes), Typha spp. (cattails), and Equisetum spp. (horsetails)
(Cross 1991, Warren et al. 1991). The surrounding vegetation is
semidesert grassland or oak savannah.
All Spiranthes populations occur where scouring floods are very
unlikely (Newman 1991). Soils supporting the populations are finely
grained, highly organic, and seasonally or perennially saturated.
Springs are the primary water source, but a creek near one population
contributes near-surface groundwater (McClaran and Sundt 1992).
Some Spiranthes life history information has been gained from
studies at one site. As with most terrestrial orchids, successful
seedling establishment probably depends on the formation of
endomycorhizae (a symbiotic association between plant root tissue and
fungi) (McClaran and Sundt 1992). The time needed for subterranean
structures to produce aboveground growth is unknown. Plants may remain
dormant in a subterranean state or remain vegetative (nonflowering) for
more than one consecutive year. Plants that flower one year can be
dormant, vegetative, or reproductive the next (McClaran and Sundt 1992,
Newman 1991). The saprophytic/autotrophic state of orchid plants may be
determined by climatic fluctuations and edaphic factors such as pH
level, temperature and soil moisture (Sheviak 1990).
Estimating Spiranthes population size and stability is difficult
because nonflowering plants are very hard to find in the dense
vegetation, and yearly counts underestimate the population because
dormant plants are not counted. McClaran and Sundt (1992) monitored
marked individuals in a Spiranthes population during two three-year
periods. They concluded that the subpopulations at both monitored sites
were stable between 1987 and 1989, although Newman (1991) later
reported that one monitored site was reduced to one nonflowering plant
in 1991. Due to the propensity of Spiranthes plants to enter and remain
in a vegetative state and the lack of new flowering plants at one
monitoring site. McClaran and Sundt (1992) also speculated that
population numbers may be declining. Problems of experimental design
acknowledged by the authors confounded McClaran and Sundt's (1992)
conclusions about population stability; the Service believes additional
long-term studies are needed to more accurately determine the stability
of Spiranthes populations.
The fire ecology of this Spiranthes is unknown, but should be
determined. Experts disagree about the role of fire in cienegas. Some
believe upland lightning-caused fires spread into cienegas and burn at
cool temperatures while others believe the wet, marsh-like habitats
will not support fires. Determining the best method of managing healthy
cienegas will depend, in part, on resolving this controversy. Studies
at one site have been inconclusive about the effect of fires on
Spiranthes (Gori and Fishbein 1991, Fishbein and Gori 1992).
Lilaeopsis schaffneriana ssp. recurva (Huachuca water umbel).
Lilaeopsis schaffneriana ssp. recurva is an herbaceous, semi-aquatic,
perennial plant with slender, erect leaves that grow from creeping
rhizomes. The leaves are cylindrical, hollow, and have septa (thin
partitions) at regular intervals. The yellow-green or bright
[[Page 16838]] green leaves are generally 1-3 mm (0.04-0.12 in) in
diameter and often 3-5 cm tall (1-2 in), but can reach up to 20 cm (8
in) tall under favorable conditions. Three to ten very small flowers
are born on an umbel that is always shorter than the leaves. The fruits
are globose, 1.5-2 mm (0.06-0.08 in) in diameter, and usually slightly
longer than wide (Affolter 1985). The species reproduces sexually and
from rhizomes asexually, the latter probably being the primary
reproductive mode.
Lilaeopsis schaffneriana ssp. recurva was first described by A.W.
Hill, based on the type specimen collected near Tucson in 1881 (Hill
1926). Hill applied the name Lilaeopsis recurva to the specimen, and
the name prevailed until Affolter (1985) revised the genus. Affolter
applied the name L. schaffneriana ssp. recurva to plants found west of
the continental divide.
Lilaeopsis has been documented from 21 sites in Santa Cruz and
Cochise Counties, Arizona, and in adjacent Sonora, Mexico, west of the
continental divide (Saucedo 1990, Warren et al. 1989, Warren et al.
1991, Warren and Reichenbacher 1991). Six of the 21 sites have been
extirpated. The 15 extant sites occur in four major watersheds--San
Pedro River, Santa Cruz River, Rio Yaqui, and Rio Sonora. All sites are
between 1,148 and 2,133 m (3,500 and 6,500 ft) elevation.
Eight Lilaeopsis populations occur in the San Pedro River watershed
in Arizona and Sonora, on sites owned or managed by private landowners,
the Fort Huachuca Military Reservation, the Coronado National Forest,
and the Bureau of Land Management (BLM)-Safford District. Two
extirpated populations in the upper San Pedro watershed in Arizona
occurred at Zinn Pond in St. David and the San Pedro River near St.
David. Cienega-like habitats suitable for Lilaeopsis were probably
common along the San Pedro River prior to 1900 (Hendrickson and
Minckley 1984, Jackson et al. 1987), but these habitats are now largely
gone.
The four Lilaeopsis populations in the Santa Cruz River watershed
probably represent very small remnants of larger populations that may
have occurred in the extensive riparian and aquatic habitat formerly
along the river. Before 1890, the spatially intermittent, perennial
flows on the middle Santa Cruz River most likely provided a
considerable amount of habitat for Lilaeopsis and other aquatic plants.
The middle section of the Santa Cruz River mainstem, about a 130-km
(80-mi) reach, flowed perennially from the U.S./Mexico border north to
the Tubac area then intermittently from Tubac north to the Tucson area
(Davis 1986). In 1859, a traveler described the Santa Cruz River in the
Tucson area as a ``* * * rapid brook * * * clear as crystal, and full
of aquatic plants, fish and tortoises of various kinds * * *'' (in
Humphrey 1958). This habitat and species assemblage no longer occurs in
the Tucson area. A population at Monkey Spring in the upper watershed
of the middle Santa Cruz River has been extirpated, although suitable
habitat still exists (Warren et al. 1991).
Two Lilaeopsis populations occur in the Rio Yaqui watershed. The
species was recently discovered at Presa Cuquiarichi, in the Sierra de
los Ajos, several miles east of Cananea, Sonora (Deecken, pers. comm.
1994). The species remains in small areas (generally less than 1 square
meter (m2)) in Black Draw, Cochise County, Arizona. Transplants
from Black Draw have been successfully established in nearby wetlands
and ponds. Recent renovation of House Pond on private land near Black
Draw extirpated the Lilaeopsis population. A population in the Rio San
Bernardino in Sonora was also recently extirpated (Gori et al. 1990).
One Lilaeopsis population occurs in the Rio Sonora watershed at Ojo de
Agua, a cienega in Sonora at the headwaters of the river (Saucedo
1990).
Lilaeopsis has an opportunistic strategy that ensures its survival
in healthy riverine systems, cienegas, and springs. In upper watersheds
that generally do not have scouring floods, Lilaeopsisoccurs in
microsites where interspecific plant competition is low. At these
sites, Lilaeopsis occurs on wetted soils interspersed with other plants
at low density, along the periphery of the wetted channel, or in small
openings in the understory. The upper Santa Cruz River and associated
springs in the San Rafael Valley, where a population of Lilaeopsis
occurs, is an example of a site that meets these conditions. the types
of microsites required by Lilaeopsis were generally lost from the main
stems of the San Pedro and Santa Cruz rivers when channel entrenchment
occurred in the late 1800s.
In stream and river main channels, Lilaeopsis can occur in
backwaters, side channels, and nearby springs. After a flood,
Lilaeopsis can rapidly expand its population and occupy disturbed
habitat until interspecific competition exceeds its tolerance. This
response was observed at Sonoita Creek in August 1988, when a scouring
flood removed about 95 percent of the Lilaeopsis population (Gori et
al. 1990). One year later, Lilaeopsis had recolonized the stream and
was again codominant with Rorippa nasturtium-aquaticum (watercress)
(Warren et al. 1991). The expansion and contraction of Lilaeopsis
populations appears to depend on the presence of ``refugia'' where the
species can escape the effects of scouring floods, a watershed with an
unaltered hydrograph, and a healthy riparian community that stabilizes
the channel.
Density of Lilaeopsis plants and size of populations fluctuates in
response to both flood cycles and site characteristics. Some sites,
such as Black Draw, have a few sparsely distributed clones, possibly
due to the dense shade of the even-aged overstory trees and deeply
entrenched channel. The Sonoita Creek population occupies 14.5 percent
of a 500.5 m\2\ (5.385 ft\2\) patch of habitat (Gori et al. 1990). Some
populations are as small as 1-2 m\2\ (11-22 ft\2\). The Scotia Canyon
population, by contrast, has dense mats of leaves. Scotia Canyon
contains the largest Lilaeopsis population, occupying about 57 percent
of the 1.450 m (4,756 ft) perennial stream reach (Gori et al. 1990, J.
Abbott, Forest Supervisor, Coronado National Forest, in litt. 1994).
The Coronado National Forest plans to continue monitoring the
populations in Scotia and Bear canyons.
While the extent of occupied habitat can be estimated, it is
impossible to determine the number of individuals in each population
because of the intermeshing creeping rhizomes. A population of
Lilaeopsis may be composed of one or many genetically distinct
individuals.
Introduction of Lilaeopsis into ponds on the San Bernardino
National Wildlife Refuge (Refuge) appears to have been successful
(Warren 1991). In 1991, Lilaeopsis was transplanted from Black Draw
into new ponds and other Refuge wetlands. Transplants placed in areas
with low plant density expanded rapidly (Warren 1991). In 1992,
Lilaeopsis naturally colonized a pond created in 1991. However, as
plant competition increased around the perimeter of the pond, the
Lilaeopsis population decreased. This response seems to confirm
observations (K. Cobble, San Bernardino National Wildlife Refuge, pers.
comm. 1994, and P. Warren, pers. comm. 1993) that other species such as
Typha sp. (cattails) will outcompete Lilaeopsis.
Other reintroductions are being considered. The Service has funded
a project to reintroduce Lilaeopsis on the Santa Cruz River and
tributaries, and the BLM (1993) plans to re-establish it along the San
Pedro River.
Sonora tiger salamander (Ambystoma tigrinum stebbinsi). The Sonora
tiger salamander is a large salamander with [[Page 16839]] light-
colored blotches or reticulation on a dark background. Snout-vent
lengths of metamorphosed individuals range from approximately 6.7-12.5
cm (2.6-4.9 in) (Jones et al. 1988. Lowe 1954). Larval salamanders are
aquatic with plume-like gills and well developed tail fins (Behler and
King 1980). Larvae hatched in the spring are large enough to
metamorphose into terrestrial salamanders from late July to early
September, but only an estimated 17-40 percent metamorphose annually.
Remaining larvae mature into branchiates (aquatic and larval-like, but
sexually mature salamanders that remain in the breeding pond) or
overwinter as larvae (Collins and Jones 1987); James Collins, Arizona
State University, pers. comm. 1993).
The Sonora tiger salamander was discovered in 1949 at the J.F.
Jones Ranch stock tank in Parker Canyon, San Rafael Valley, Arizona
(Reed 1951). Based on color patterns of metamorphosed animals, Lowe
(1954) described the Sonora tiger salamander from southern Santa Cruz
County, Arizona, as the subspecies stebbinsi of the broad-ranging tiger
salamander (Ambystoma tigrinum). However, again based on color
patterns, Gehlbach (1965, 1967) synonomized A. t. stebbinsi and A. t.
utahense (from the Rocky Mountains region) with A. t. nebulosum (from
northern Arizona and New Mexico). Nevertheless, A. t. stebbinsi
continued to be recognized in the scientific literature (Jones et al.
1988).
Jones et al. (1988) found Lowe's description of color patterns in
A. t. stebbinsi was only accurate for recently metamorphosed
individuals and that older metamorphosed adults exhibited either a
distinctive reticulate pattern or large light-colored blotches on a
dark background similar to A. t. mavortium, found in the central United
States and adjacent portions of Mexico. Starch gel electrophoresis of
21 presumptive gene loci of A. t. stebbinsi were compared with gene
loci of A. rosaceum (from Sonora). A. t. mavortium, and A. t. nebulosum
(Jones et al. 1988). Based on this analysis, distinctive reticulate
color patterns, low heterozygosity, and apparent geographic isolation,
subspecific designation of A. t. stebbinsi was considered warranted by
Collins and Jones (1987) and Jones et al. (1988). Further analysis of
mitochondrial DNA reaffirmed subspecific designation and suggested that
A. t. stebbinsi may have been derived from hybridization between A. t.
nebulosum and A. t. mavortium (Collins et al. 1988).
The grassland community of the San Rafael Valley and surrounding
hillsides, where all extant populations of A. t. stebbinsi occur, may
represent a relictual grassland and a refugium for tiger salamander
populations that became isolated and, over time, genetically distinct.
Based on color patterns and electrophoretic analysis, Ambystoma
collected in Mexico at one site in Sonora and 17 sites in Chihuahua
were all A. rosaceum, not A. t. stebbinsi (Jones et al. 1988).
Reanalysis of reported A. t. stebbinsi collected in Sonora (Hansen and
Tremper 1979) and at Yepomera, Chihuahua (Van Devender 1973) revealed
that these specimens were actually A. rosaceum (Jones et al. 1988).
Collins et al. (1988) list 18 recorded sites for the Sonora tiger
salamander. All of these sites are in the headwaters of the Santa Cruz
River, including sites in the San Rafael Valley and adjacent foothills
of the Patagonia and Huachuca Mountains and the Canelo Hills, in Santa
Cruz and Cochise Counties, Arizona. The taxon is currently extant at 15
of these sites, where populations of mature branchiates range from
approximately 50 to several hundred (Collins and Jones 1987).
Populations of Sonora tiger salamanders also have been discovered
recently in Scotia Canyon on the western slopes of the Huachuca
Mountains (Jeff Howland, Arizona Game and Fish Department, pers. comm.
1993) and in Copper Canyon of the Huachuca Mountains (Russell Duncan,
Southwestern Field Biologists, pers. comm. 1993). Salamanders
tentatively identified as Sonora tiger salamander also have been found
recently at Portrero del Alamo at the Los Fresnos cienega in the
headwaters of the San Pedro River, San Rafael Valley, Sonora, Mexico
(Sally Stefferud, U.S. Fish and Wildlife Service, pers. comm. 1993). In
addition, a single terrestrial Sonora tiger salamander was found near
Oak Spring in Copper Canyon of the Huachuca Mountains (J. Howland,
pers. comm. 1993). This individual probably moved from the newly
discovered aquatic population located approximately 1 km (0.6 mi) to
the southwest. All historic and extant sites occur within 31 km (19 mi)
of Lochiel, Arizona. The Los Fresnos and Oak Spring sites are springs
or cienegas; all other sites are livestock tanks or impounded cienegas.
Historically, the Sonora tiger salamander probably inhabited springs
and cienegas where permanent or nearly permanent water allowed survival
of mature branchiates.
Other potential localities have been surveyed in or near the San
Rafael Valley, but no other Sonora tiger salamander populations have
been found. A. rosaceum and A. t. velasci occur at localities in Sonora
and Chihuahua to the south and east of the extant range of the Sonora
tiger salamander (Collins 1979, Collins and Jones 1987, Van Devender
and Lowe 1977). A. t. mavortium occurs at scattered localities to the
east in the San Pedro, Sulphur Springs, and San Simon Valleys (Collins
and Jones 1987), but at least some of these populations were introduced
by anglers and bait collectors (Collins 1981, Lowe 1954, Nickerson and
Mays 1969).
A variety of human activities threaten the Sonora tiger salamander.
The species has been recently extirpated from at least three of the 18
localities described by Collins et al. (1988). Disease and predation by
introduced nonnative fish and bullfrogs (Rana catesbeiana) have been
implicated in the extirpation of these populations (Collins and Jones
1987). Tiger salamanders are also widely used as fishing bait in
Arizona, and this use poses additional threats. Other subspecies of
tiger salamander introduced into habitats of the Sonora tiger
salamander for bait propagation could, through interbreeding,
genetically swamp the distinct A. t. stebbinsi populations (Collins and
Jones 1987). Collecting Sonora tiger salamanders for bait could also
extirpate or greatly reduce populations. Additional threats include
habitat destruction, reduced fitness resulting from low genetic
heterozygosity, and the increased probability of stochastic extirpation
characteristic of small populations.
Previous Federal Action
Federal government actions on Spiranthes delitescens, Lilaeopsis
schaffneriana ssp. recurva, and Sonora tiger salamander began with
their inclusion in various Service notices of taxa under review for
listing as endangered or threatened species. Sonora tiger salamander
was included as a category 2 candidate in the first notice of review of
vertebrate wildlife (December 30, 1982; 47 FR 58454), and in subsequent
notices published September 18, 1985 (50 FR 37958), and January 6, 1989
(54 FR 554). Category 2 candidates are those for which the Service has
some evidence of vulnerability, but for which there is insufficient
scientific and commercial information to support a proposed rule to
list them as threatened or endangered. The most recent animal notice,
published November 15, 1994 (59 FR 58982), included the Sonora tiger
salamander in category 1. Category 1 includes those taxa for which the
Service has sufficient information to [[Page 16840]] support proposed
rules to list the species as threatened or endangered.
Lilaeopsis schaffneriana ssp. recurva, then under the name L.
recurva, was included as a category 2 candidate in the November 28,
1983 (45 FR 82480) and September 27, 1985 (50 FR 39526) plant notices.
It was included under its present name as a category 1 candidate in the
February 21, 1990 (55 FR 6184), and September 30, 1993 (58 FR 51144),
notices.
Spiranthes delitescens was included for the first time in the
September 30, 1993, plant notice. It was included in that notice as a
category 1 candidate.
On June 3, 1993, the Department of the Interior, Washington, DC,
received three petitions, dated May 31, 1993, from a coalition of
conservation organizations (Suckling et al. 1993). The petitioners
requested the listing of Spiranthes, Lilaeopsis, and Sonora tiger
salamander as endangered species pursuant to the Endangered Species Act
of 1973, as amended (16 U.S.C. 1531 et seq.). On December 14, 1993, the
Service published a notice of three 90-day findings that the petitions
presented substantial information indicating that listing these three
species may be warranted, and requested public comments and biological
data on the status of the species (58 FR 65325).
Section 4(b)(3)(B) of the Act requires the Secretary to reach a
final decision on any petition accepted for review within 12 months of
its receipt. Publication of this proposed rule constitutes the
warranted findings for the petitioned actions.
Summary of Factors Affecting the Species
Section 4 of the Endangered Species 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. 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 Spiranthes delitescens Sheviak (Canelo
Hills ladies'-tresses), Lilaeopis schaffneriana spp. recurva (A.W.
Hill) Affolter (Huachuca water umbel), and the Sonora tiger salamander
(Ambystoma tigrinum stebbinsi Lowe) are as follows:
A. The present or threatened destruction, modification, or
curtailment of its habitat or range. Humans have affected southwestern
riparian systems over a period of several thousand years. From
prehistoric or historic times, human settlement in southern Arizona has
centered on oasis-like cienegas, streams, and rivers. Before the early
1800s, indigenous peoples and missionaries used southern Arizona
cienegas and riparian areas mostly for subsistence enterprises,
including wood cutting, agriculture (including livestock grazing), and
food and fiber harvesting. In the early 1800s, fur trappers nearly
eliminated beaver from southern Arizona streams and rivers (Davis 1986)
significantly changing stream morphology. In addition, human-caused
fires and trails may have significantly altered riparian systems (Bahre
1991, Dobyns 1981).
There was a significant human population increase in southern
Arizona and northern Sonora in the early to middle 1800s. New
immigrants substantially increased subsistence and commercial livestock
production and agriculture. By the late 1800s, many southern Arizona
watersheds were in poor condition primarily due to uncontrolled
livestock grazing, mining, hay harvesting, timber harvesting, and other
management practices, such as fire suppression (Bahre 1991, Humphrey
1958, Martin 1975). The watershed degradation caused by these
management practices led to widespread erosion and channel entrenchment
when above average rainfall and flooding occurred in the late 1800s
(Bahre 1991, Bryan 1925, Dobyns 1981, Hastings and Turner 1980,
Hendrickson and Minckley 1984, Martin 1975, Sheridan 1986, Webb and
Betancourt 1992). These events contributed to long-term cienega and
riparian habitat degradation throughout southern Arizona and northern
Mexico. Physical evidence of cienega and other riparian area changes
can be found in the black organic soils of the drainage cut banks in
the San Rafael Valley (Hendrickson and Minckley 1984), San Pedro River
(Hereford 1992), Black Draw, and elsewhere. Although these changes took
place nearly a century ago, the ecosystem has not fully recovered and,
in some areas, may never recover.
Wetland habitat degradation and loss continues today. Human
activities such as groundwater overdrafts, surface water diversions,
impoundments, channelization, improper livestock grazing, chaining,
agriculture, mining, road building, nonnative species introductions,
urbanization, wood cutting, and recreation all contribute to riparian
and cienega habitat loss and degradation in southern Arizona. The local
and regional effects of these activities are expected to increase with
increasing human population. Each threat is discussed in more detail
below.
Growing water demand threatens the existence of southern Arizona
perennial surface water and the species that depend on it. The North
American Free Trade Agreement (NAFTA) will likely stimulate borderland
development, with a concurrent water demand increase that could
accelerate riparian area destruction and modification and increase
threats to plants and animals dependent on surface water, including the
species in this proposal.
The largest area currently available for recovery of Lilaeopsis is
the San Pedro River along the perennial reach between Hereford and
Fairbank. Whether or not the species can be recovered there depends
largely on the future presence of perennial surface flows in the river
and a natural unregulated hydrograph. Perennial flow in the San Pedro
River between Hereford and Fairbank comes from a deep regional aquifer
and a shallower floodplain (alluvial) aquifer (Arizona Department of
Water Resources 1991, Arizona Department of Water Resources 1994,
Jackson et al. 1987, Vionnet and Maddock 1992). Groundwater pumping
from both the regional and floodplain aquifers has occurred for some
time and threatens the base flow in the river (Jackson et al. 1987,
University of Arizona San Pedro Interdisciplinary Team 1991). Pumping
from wells used primarily for agriculture, particularly in the
Palominas and Hereford area, is having the largest current effect on
the floodplain aquifer (Arizona Department of Water Resources 1994,
Jackson et al. 1987). A significant effect to the regional aquifer
results from groundwater pumping from deeper wells that are the main
sources of municipal, military, and industrial water for Sierra Vista,
Fort Huachuca Military Reservation, and Huachuca City (Jackson et al.
1987, Arizona Department of Water Resources 1991 and 1994, Vionnet and
Maddock 1992). Groundwater pumping from this deep regional aquifer has
formed a cone of depression in the Sierra Vista/Fort Huachuca area
intercepting mountain front flows that would have contributed to
aquifer recharge (Arizona Department of Water Resources 1994, Jackson
et al. 1987).
Groundwater pumping is expected to increase with human population
growth. In anticipation of population growth, Fort Huachuca Military
Reservation has filed a claim for 10,087 acre-feet (A-F) per year of
tributary groundwater, more than three times the estimated 3,000 A-F
currently used (Arizona Department of Water Resources 1991). Even if
water conservation measures are employed, groundwater drafts and the
capture of mountain front recharge are likely to adversely affect flows
in the San Pedro [[Page 16841]] River. If base flow in the river
continues to decrease, the future existence of the riparian plant
community is threatened (Arizona Department of Water Resources 1994,
Jackson et al. 1987). If the groundwater drops below the elevation of
the channel bed, the wetland plant (herb) association where Lilaeopsis
is found will be the first plant association lost (Arizona Department
of Water Resources 1994).
Fort Huachuca Military Reservation also relies on water from a well
and springs in Garden Canyon (Arizona Department of Water Resources
1991). These diversions and pumping could dewater the stream and damage
or destroy the Lilaeopsis population, particularly during below-average
rainfall periods.
Flows in certain reaches of the Santa Cruz River remained perennial
until groundwater pumping lowered the water table below the streambed.
In 1908, the water table near Tucson was above the streambed, but from
1940-1969, the water table was 6.0-21.0 m (20-70 ft) below the
streambed (De la Torre 1970). Recovery of perennial flow in the Santa
Cruz River and of Lilaeopsis near Tucson is unlikely, given the
importance of groundwater for the metropolitan area.
Groundwater pumping in Mexico threatens Lilaeopsis populations on
both sides of the border. South of the San Bernardino National Wildlife
Refuge, groundwater is being pumped to irrigate farmlands in Mexico,
and this pumping threatens to dry up the springs and streams that
support several listed endangered fish and a population of Lilaeopsis.
The large copper mine at Cananea. Sonora, pumps groundwater for
processing and support services. Although little is known about how
groundwater pumping near Cananea may affect the spring at Ojo de Agua
de Cananea, it is likely that overdrafts would decrease springflow or
dewater the spring, extirpating the Lilaeopsis population. The spring
at Ojo de Aqua de Cananea is also the main municipal water source for
the town of Cananea. This water diversion, particularly if increased,
may adversely affect Lilaeopsis.
Sections of may southern Arizona rivers and streams have been
channelized for flood control, which disrupts natural channel dynamics
and promotes the loss of riparian plant communities. Channelization
modifies the natural hydrograph above and below the channelized
section, which may adversely affect Lilaeopsis and Spiranthes.
Channelization will continue to contribute to riparian habitat decline.
Additional channelization will accelerate the loss any/or degradation
of Lilaeopsis and Spiranthes habitat.
Dredging extirpated the Lilaeopsis population in House Pond. near
the extant population in Black Draw (Warren et al. 1991). The
Lilaeopsis population at Zinn Pond in St. David near the San Pedro
River was probably lost when the pond was dredged and deepened. This
population was last documented in 1953 (Warren et al. 1991).
Livestock grazing potentially affects Lilaeopsis at the ecosystem,
community, population, and individual levels. Cattle generally do not
eat Lilaeopsis because the leaves are too close to the ground, but they
can trample plants. Lilaeopsis is capable of rapidly expanding in
disturbed sites and could recover quickly from light trampling by
extending undisturbed rhizomes (Warren et al. 1991). Light trampling
may also keep plant density low providing favorable Lilaeopsis
microsites.
Poor livestock grazing management can destabilize stream channels
and disturb cienega soils creating conditions unfavorable for
Lilaeopsis. which requires stable stream channels and cienegas. Such
management can also change riparian community structure and diversity
causing a decline in watershed conditions. Poor livestock grazing
management is widely believed to be one of the most significant factors
contributing to regional stream channel entrenchment in the late 1800s.
Poor livestock grazing management in Mexico has severely degraded
the riparian area along Black Draw and its watershed. The degraded
habitat most likely contributed to the severity of a destructive
scouring flood on San Bernardino Creek in 1988, which extirpated two
patches of Lilaeopsis. Overgrazing is occurring immediately adjacent to
the San Bernardino National Wildlife Refuge and has destabilized the
channel of Black Draw. A headcut moving upstream threatens to undermine
the riparian area recovery that has occurred since the refuge was
acquired. The refuge is implementing management to avoid the
destructive downstream grazing effects.
Well managed livestock grazing and Lilaeopsis are compatible. The
fact that Lilaeopsis and its habitat occur in the upper Santa Cruz
River system in the San Rafael Valley attests to the good land
stewardship of the private landowner and of prior generations of the
family.
The effect of livestock grazing on Spiranthes is unclear. A
Spiranthes population growing at a site grazed for more than 100 years
is larger and more vigorous than a population growing at a site
ungrazed since 1969 (McClaran and Sundt 1992, Newman 1991). Sundt
(pers. comm. in Newman 1991) has suggested differences in soil moisture
and topography between the two sites could explain the differences in
Spiranthes population size and vigor. Another explanation is that S.
delitescens, like many species in the genus, shows an affinity for
habitats with sparse herbaceous cover (McClaran and Sundt 1992).
Further research is needed, but the Service's preliminary conclusion is
that well managed livestock grazing does not harm Spiranthes
populations.
Livestock often denude the vegetation around stock tanks. The
impact of this effect on Sonora tiger salamander populations is unknown
(Collins and Jones 1987), however, the Santa Cruz long-toed salamander
(Ambystoma macrodactylum croceum), a related endangered species from
the central coast of California requires dense vegetation around
breeding ponds and surrounding uplands used by mature metamorphs (U.S.
Fish and Wildlife Service 1986). Aquatic, shoreline, and nearby
terrestrial vegetation cover at Sonora tiger salamander breeding ponds
likely conseals salamanders from predators and provides a forage base
for invertebrates that make up a portion of the salamander's diet. In
addition, livestock probably trample metamorphs, eggs, and possibly
brachiate salamanders. Although Sonora tiger salamanders persist in
stock tanks heavily used by cattle, the effects of grazing and
trampling probably reduce the viability of these populations.
Sand and gravel mining along the San Pedro, Babocomari, and Santa
Cruz Rivers in the United States has occurred, and probably will
continue unless regulated, although no mining occurs within the San
Pedro Riparian National Conservation Area. Sand and gravel mining
removes riparian vegetation and destabilizes the ecosystem, which could
cause Spiranthes or Lilaeopsis habitat or population losses upstream or
downstream from the mining. These mines also pump groundwater for
processing, and could locally affect groundwater reserves and perennial
stream base flows. Since 1983, groundwater has been used to wash sand
and gravel mined near the Babocomari River. 0.8 km (0.5 mi) west of
highway 90 (Arizona Department of Water Resources 1991). This activity
could affect at least one Spiranthes population. [[Page 16842]]
Rural and urban development, road building, chaining, agriculture,
mining, and other land disturbances that degrade the watershed can
adversely affect Lilaeopsis. These activities are common in the middle
Santa Cruz basin, but much less prevalent in the San Pedro basin. For
these reasons, conservation and recovery of the middle Santa Cruz River
is unlikely, but may still be possible for the upper San Pedro
watershed, given region-wide planning decisions favorable to good
watershed management. Increased development in the upper San Pedro
Valley, including the expansion of existing cities and increased rural
development, will likely increase erosion and have other detrimental
hydrologic effects.
There are few watershed-level disturbances in the upper Santa Cruz
and Black Draw drainages. There were irrigated fields in the Black Draw
watershed, but these were abandoned when the Service acquired the area
as a refuge. The fields are returning to natural vegetation. The San
Rafael Valley, which contains the upper Santa Cruz River, is privately
owned, well managed, and currently undeveloped, with few watershed
disturbing activities. However, there is potential for commercial
development in the upper Santa Cruz basin and resulting watershed
effects.
Riparian areas and cienegas offer oasis-like living and
recreational opportunities for residents of southern Arizona and
northern Sonora. Riparian areas and cienegas such as Sonoita Creek, the
San Pedro River, Canelo Hills cienega, and the perennial creeks of the
Huachuca Mountains receive substantial recreational visitation, and
this is expected to increase with the increasing southern Arizona
population. While well-managed recreation is unlikely to extirpate
Spiranthes or Lilaeopsis populations, severe impacts in unmanaged areas
can compact soils, destabilize steam banks, and decrease riparian plant
density.
Stream headcutting threatens the Lilaeopsis and presumed Sonora
tiger salamander populations at Los Fresnos cienega in Sonora. Erosion
is occurring in Arroyo Los Fresnos downstream from the cienega and the
headcut is moving upstream. The causes of this erosion are uncertain,
but are presumably from livestock overgrazing and roads in this
sparsely populated region. If the causes of this erosion are left
unchecked and headcutting continues, it is likely the cienega habitat
will be lost within the foreseeable future. The loss of Los Fresnos
cienega may extirpate the Lilaeopsis and Sonora tiger salamander
populations. If the salamanders at the Los Fresnos cienega are Sonora
tiger salamanders, this would represent the only known natural cienega
habitat occupied by an aquatic population of this species.
The 15 extant aquatic Sonora tiger salamander populations described
by Collins et al. (1988) and the new localities in Scotia Canyon and
Copper Canyon are all in stock tanks or impounded cienegas constructed
to collect runoff for livestock. Most of these tanks likely date to the
1920s and 1930s when government subsidies were available to offset
construction costs (Brown 1985). These stock tanks, to some degree,
have created and replaced permanent or semi-permanent Sonora tiger
salamander water sources.
Although the tanks provide relatively permanent aquatic habitats,
current management and the dynamic nature of these artificial
impoundments compromise their ability to support salamander populations
in the long term. The tanks collect silt from upstream drainages and
must be cleaned out periodically, typically with heavy earth moving
equipment. This maintenance is done when stock tanks are dry or nearly
dry at an average interval of about 15 years (L. Dupee. Coronado
National Forest, Sierra Vista, Arizona, pers. comm. 1993). As the tanks
dry out, aquatic salamanders typically metamorphose and migrate from
the pond. However, if water is present during maintenance, some
branchiate salamanders would likely be lost due to excavation of the
remaining aquatic habitat. Any terrestrial metamorphs at the tank or in
areas disturbed would also be lost during maintenance activities.
Flooding and drought pose additional threats to stock tank
populations of Sonora tiger salamanders. The tanks are simple earthen
impoundments without water control structures. Heavy flooding could
erode and breach downstream berms resulting in aquatic habitat loss.
Long-term drought could dry up the tanks.
Sonora tiger salamanders have persisted in stock tanks despite
periodic maintenance, flooding, and drought. If the tanks refill soon
after events that damage the aquatic habitat, they could presumably be
recolonized through terrestrial metamorph reproduction. However, if a
tank was dry for several years and isolated from other salamander
populations, insufficient terrestrial salamanders may remain and
immigration from other populations may be inadequate to recolonize the
stock tank. Potential grazing practice changes also threaten aquatic
Sonora tiger salamander populations. Stock tanks could be abandoned or
replaced by other watering facilities, such as windmills and troughs,
which do not provide habitat for salamanders.
B. Overutilization for commercial, recreational, scientific, or
educational purposes. No commercial, recreational, or educational uses
for Lilaeopsis are known. A limited amount of scientific collecting is
likely, but is expected to pose no threat to the species.
Although no specific cases of commercial Spiranthes delitescens
collecting have been documented, commercial dealers, hobbyists, and
other collectors are widely known to significantly threaten some
natural orchid populations. The commercial value of an orchid may
increase after it is listed as threatened or endangered. To limit the
possible adverse effects of illegal collecting, no specific Spiranthes
population locations are discussed in this proposed rule, nor will
critical habitat be designated. No recreational or educational uses for
Spiranthes are currently known. The small amount of scientific
collecting that has occurred is regulated by the Arizona Native Plant
Law (A.R.S. Chapter 7, Article 1).
Collecting Ambystoma in the San Rafael Valley of Arizona is
currently prohibited by Arizona Game and Fish Commission Order 41.
Collins and Jones (1987) reported an illegal Ambystoma collection from
the San Rafael Valley and suspected that bait collectors and anglers
often move salamanders among stock tanks. The extent of this activity
and its threat to populations is unknown. However, all Sonora tiger
salamander populations are relatively small (Collins and Jones 1987).
Collecting may significantly reduce the size of branchiate populations
and increase the chance of extirpations.
C. Disease or predation. Neither Lilaeopsis nor Spiranthes are
known to be threatened by disease or predation.
Sonora tiger salamanders are invariably eliminated through
nonnative fish predation, particularly by sunfish and catfish (Collins
and Jones 1987). Nonnative fish introductions were implicated in three
recent Sonora tiger salamander extirpations from stock tanks (Collins
et al. 1988). The effect of native fishes on salamander populations is
unknown, but some native species may also prey on Sonora tiger
salamanders.
Bullfrogs occur at some Sonora tiger salamander localities. These
introduced predators likely prey on salamander eggs, larvae, and adults
(Collins et al. 1988). They may also be a vector for a disease with
symptoms similar to Aeromonas infection (``red leg'') (Marcus 1981)
that killed all branchiate [[Page 16843]] salamanders at Huachuca Tank,
Parker Canyon Tank #1, and Inez Tank in 1985 (Collins et al. 1988). The
latter two tanks were recolonized within the next two years, presumably
by reproducing terrestrial metamorphs that survived the disease.
However, no recolonization of Huachuca Tank had occurred as of spring
1988 (Collins et al. 1988), and the species was not observed there
during surveys in 1993 (J. Collins, pers. comm. 1993). Nonnative fish
were also present at Huachuca Tank and likely contributed to this
extirpation.
Surveys conducted in 1993 and 1994 revealed that nonnative fish and
bullfrogs were recently introduced at several northern San Rafael
Valley Sonora tiger salamander localities. Populations appear very low
or are extirpated at several of these localities, particularly in the
northwestern portion of the valley. Additional survey work in 1994 will
clarify the status of these populations. In contrast, populations in
the southeastern portion of the valley appear large and robust (J.
Collins, pers. comm. 1994).
D. The inadequacy of existing regulatory mechanisms. Many Federal
and State laws and regulations can protect these three species and
their habitat. However, Federal and State agency discretion allowed
under these laws still permits adverse affects on listed and rare
species. Adding Lilaeopsis, Spiranthes, and the Sonora tiger salamander
to the endangered species list will help reduce adverse affects to
these species and will direct Federal agencies to work towards their
recovery.
None of the taxa in this proposed rule are considered rare,
threatened, or endangered by the Mexican government (Secretario de
Desarrollo Urbano Y Ecologia 1991), nor do their habitats receive
special protection in Mexico.
On July 1, 1975, all species in the Orchid family (including
Spiranthes delitescens) were included in Appendix II of the Convention
on International Trade in Endangered Species of Wild Fauna and Flora
(CITES). CITES is an international treaty established to prevent
international trade that may be detrimental to the survival of plants
and animals. A CITES export permit must be issued by the exporting
county before an Appendix II species may be shipped. CITES permits may
not be issued if the export will be detrimental to the survival of the
species or if the specimens were not legally acquired. However, CITES
does not itself regulate take or domestic trade. CITES provides no
protection to Lilaeopsis or the Sonora tiger salamander.
The Lacey Act (16 U.S.C. 3371 et seq.), as amended in 1982,
provides some protection for these three species. Under the Lacey Act
it is prohibited to import, export, sell, receive, acquire, purchase,
or engage in interstate or foreign commerce in any species taken,
possessed, or sold in violation of any law, treaty, or regulation of
the United States, any Tribal law, or any law or regulation of any
State. Interstate transport of protected species occurs despite the
Lacey Act because enforcement is difficult.
The Federal Land Policy and Management Act of 1976 (FLPMA) (43
U.S.C. 1701 et seq.) and National Forest Management Act of 1976 (NFMA)
(16 U.S.C. 1600 et seq.) direct Federal agencies to prepare
programmatic-level management plans to guide long-term resource
management decisions. The goals of the Coronado National Forest Plan
(Plan) include a commitment to maintain viable populations of all
native wildlife, fish, and plant species within the Forest's
jurisdiction through improved habitat management (Coronado National
Forest 1986a). The Plan provides a list of rare plants and animals
found on the Forest, but gives only a very general description of
programmatic-level management guidelines and expected effort (Coronado
National Forest 1986a). The Coronado National Forest is committed to
multiple use, and where the demands of various interest groups
conflict, the Forest must make decisions that represent compromises
among these interests (Coronado National Forest 1986b). These types of
compromises have sometimes resulted in adverse effects to listed
endangered and threatened species.
The Plan's endangered species program includes participation in
reaching recovery plan objectives for listed species, habitat
coordination and surveys for listed species, and habitat improvement
(Coronado National Forest 1986b). After acknowledging budget
constraints, the Plan states that studies of endangered plants will
occur at approximately the 1980 funding level. The Coronado National
Forest, which manages habitat for 10 of the 18 extant aquatic Sonora
tiger salamander populations, considers the Sonora tiger salamander a
sensitive species and a management indicator species, which receives
special consideration in land management decisions (Coronado National
Forest 1986a). The ability of the Forest Service to manage the three
species addressed here is limited because many of the populations occur
off Forest Service lands and/or require ecosystem-wide management
largely beyond Forest Service control.
The National Environmental Policy Act of 1969 (NEPA) (42 U.S.C.
Sec. 4321-4370a) requires Federal agencies to consider the
environmental impacts of their actions. NEPA requires Federal agencies
to describe a proposed action, consider alternatives, identify and
disclose potential environmental impacts of each alternative, and
involve the public in the decision-making process. It does not require
Federal agencies to select the alternative having the least significant
environmental impacts. A Federal action agency may choose an action
that will adversely affect listed or candidate species provided these
effects were known and identified in a NEPA document.
All three species in this proposed rule inhabit wetlands that have
varying protection under section 404 of the Federal Water Pollution
Control Act of 1948 (33 U.S.C. 1251-1376), as amended, and Federal
Executive Orders 11988 (Floodplain Management) and 11990 (Protection of
Wetlands). Cumulatively, these Federal regulations have been inadequate
to halt population extirpations and habitat losses for the three
proposed species.
The Arizona Native Plant Law (A.R.S. Chapter 7, Article 1) protects
Spiranthes delitescens and Lilaeopsis schaffneriana spp. recurva as
``highly safeguarded'' species. A permit from the Arizona Department of
Agriculture (ADA) must be obtained to legally collect these species on
public or private lands in Arizona. Permits may be issued for
scientific and educational purposes only. It is unlawful to destroy,
dig up, mutilate, collect, cut, harvest, or take any living ``highly
safeguarded'' native plant from private, State, or Federal land without
a permit. However, private landowners and Federal and State public
agencies may clear land and destroy habitat after giving the ADA
sufficient notice to allow plant salvage. Despite the protections of
the Arizona Native Plant Law, legal and illegal damage and destruction
of plants and habitat occur.
Collecting Ambystoma in the San Rafael Valley is prohibited under
Arizona Game and Fish Commission Order 41, except under special permit.
Nevertheless, illegal collecting occurs (Collins and Jones 1987). The
species is listed by the State as endangered (Arizona Game and Fish
Department 1988), however, this designation affords the species or its
habitat no legal protection. Transport and stocking of live bullfrogs
and fishing with live bait fish or Ambystoma within the range of this
salamander in Arizona is prohibited [[Page 16844]] by Arizona Game and
Fish Commission Orders 41 and R12-4-316, respectively. However,
bullfrogs and nonnative fish are present at several extant and historic
Sonora tiger salamander localities and introductions continue (Collins
and Jones 1987; James Collins, pers. comm. 1994). Furthermore,
abandonment, modification, or breaching of stock tanks is allowed on
either private or public lands. Such actions could eliminate Sonora
tiger salamander populations.
State of Arizona Executive Order Number 89-16 (Streams and Riparian
Resources), signed June 10, 1989, directs State agencies to evaluate
their actions and implement changes, as appropriate, to allow for
riparian resources restoration. Implementation of this regulation may
ameliorate adverse effects of some State actions on the species in this
rule.
E. Other natural or manmade factors affecting its continued
existence. Arizona anglers and commercial bait dealers often introduce
larval tiger salamanders into ponds for future bait collecting (Lowe
1954, Collins et al. 1988). Collins and Jones (1987) reported that
tiger salamanders were illegally collected from the San Rafael Valley
and transported to at least two tanks in the northern Patagonia
Mountains. Bait dealers or others moving Sonora tiger salamanders to
new locations could establish new populations. Collins and Jones (1987)
suggest that moving of salamanders has greatly influenced their present
distribution in the San Rafael Valley. Moving could also transmit
disease and cause unintentional fish or bullfrog introductions, which
would extirpate extant populations.
Moving poses an additional threat. A. t. mavortium is common in
Arizona stock tanks and ponds to the east of the San Rafael Valley.
Bait dealers and anglers introduced many of these populations (Collins
1981, Collins and Jones 1987). If A. t. mavortium is introduced into
Sonora tiger salamander localities, populations could be lost due to
genetic swamping by interbreeding of the two subspecies.
Two populations of Lilaeopsis have been lost due to unknown causes.
Despite the presence of suitable habitat, no plans have been observed
at Monkey Spring near Sonita Creek since 1965. Lilaeopsis collected in
1958 along the San Pedro River near St. David, but no longer exists
there, nor is their suitable habitat.
Aggressive nonnative plants disrupt the native riparian plant
community. The nonnative Sorghum halepense (Johnson grass) is invading
one Spiranthes site (Gori in litt. 1993). This tall grass forms a dense
monoculture, displacing less competitive native plants. If Johnson
grass continues to spread, the Spiranthes population may be lost (Gori
in litt. 1993). Cynodon dactylon (Bermuda grass) also displaces native
riparian plants, including cottonwoods and willows that stabilize
stream channels. Bermuda grass forms a thick sod in which many native
plants are unable to establish. In certain microsites, Bermuda grass
may directly compete with Lilaeopsis or Sprianthes. There are no known
effective methods for eliminating Bermuda grass or Johnson grass from
natural plant communities.
Rorippa nasturtium-aquaticum (watercress) is another nonnative
plant now abundant along perennial streams in Arizona. It is successful
in disturbed areas and can form dense monocultures that can outcompete
Lilaeopsis populations.
The limited number of populations and individuals threatens all
three taxa in this proposed rule with demographic and environmental
stochastic extinction. The restriction of these three species to a
relatively small area in southeastern Arizona and adjacent Sonora also
increases the chance that a single environmental catastrophe, such as a
severe tropical storm, could eliminate populations or cause extinction.
This is of particular concern for Sonora tiger salamanders inhabiting
stock tanks that could wash out during a storm. Furthermore, Sonora
tiger salamander genetic heterozygosity is the lowest reported for any
salamander (Jones et al. 1988). Low heterozygosity indicates low
genetic variation, which increases demographic stochasticity and the
chance of local extirpations (Shafer 1990).
Finding of a Sonora tiger salamander recently at Oak Spring,
approximately 1.0 km (0.6 mi) from the nearest known aquatic
population, provides evidence these animals are capable of at least
that distance of overland dispersal. Seasonal movement to and from
breeding ponds is a common phenomenon in amphibians. Distances of these
seasonal movements are generally less than 0.5 km (0.3 mi), although
movements of more than 11 km (7 mi) have been documented for the red-
bellied newt (Taricha rivularis) (Zug 1993). The ability of Sonora
tiger salamanders to move between populations is unknown, but arid
grassland, savanna, or pine-oak woodland separates all populations and
movement through these relatively dry landscapes is probably limited.
Movement would be most likely during storms or where wet drainages are
available as movement corridors. The distance between aquatic
populations of Sonora tiger salamander is more than 2 km (1.2 mi) in
most cases, and much greater distances separate many of the sites.
Thus, even if these salamanders are capable of moving relatively long
distances, some populations are probably effectively geographically
isolated. Small isolated populations have an increased probability of
extirpation (Wilcox and Murphy 1985). Once populations are extirpated,
natural recolonization of these isolated habitats may not occur
(Frankel and Soule 1981).
The Service has carefully assessed the best scientific and
commercial information available regarding the past, present, and
future threats faced by these taxa in determining to propose this rule.
These three taxa are vulnerable to one or more of the following
threats--habitat degradation and loss through groundwater pumping,
livestock grazing, watershed degradation, flooding, drought,
urbanization, and recreation; nonnative plant and vertebrate
competition or predation; disease; and increased extirpation chance due
to low genetic variation in the Sonora tiger salamander. The limited
distributions of these taxa and the small size of most extant
populations makes them particularly vulnerable to extinction from
stochastic events.
Because Spiranthes, Lilaeopsis, and the Sonora tiger salamander are
in danger of extinction throughout all or significant portions of their
ranges, they fit the Act's definition of endangered. Based on the
Service's evaluation of the status and threats facing these species,
the preferred action is to propose Spiranthes, Lilaeopsis, and the
Sonora tiger salamander as endangered. The Service believes that
designation of critical habitat is prudent for the Lilaeopsis and the
Sonora tiger salamander, but finds that critical habitat is not now
determinable for these two species. Critical habitat designation would
not be prudent for the Spiranthes. The rationales for these decisions
are discussed in the following section of this proposal.
Critical Habitat
Critical habitat is defined in Section 3 of the Act as--(i) The
specific areas within the geographic area occupied by a species, at the
time it is listed in accordance with the Act, on which are found those
physical or biological features (I) essential to the conservation of
the species and (II) that may require special management considerations
or protection and; (ii) specific areas outside the geographic area
occupied by a species at the time it is listed, upon [[Page 16845]] a
determination that such areas are essential for the conservation of the
species. ``Conservation'' means the use of all methods and procedures
needed to bring the species to the point at which listing under the Act
is no longer necessary.
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 242.12) require that, to the maximum extent prudent
and determinable, the Secretary designate critical habitat at the time
a species is determined to be endangered or threatened. The Service
finds that designation of critical habitat is not prudent for
Spiranthes delitescens at this time. Service regulations (50 CFR
424.12(a)(1)) state that designation of critical habitat is not prudent
when one or both of the following situations exist--(1) the species is
threatened by taking or other human activity, and identification of
critical habitat can be expected to increase the degree of threat to
the species, or (2) such designation of critical habitat would not be
beneficial to the species.
As discussed under Factor B in the ``Summary of Factors Affecting
the Species,'' Spiranthes is threatened by collecting. If it is listed,
collecting of Spiranthes would be prohibited under the Act in cases of
(1) removal and reduction to possession from lands under Federal
jurisdiction, or malicious damage or destruction on such lands; and (2)
removal, cutting, digging up, or damaging or destroying Spiranthes in
knowing violation of any State law or regulation, including State
criminal trespass law. Such provisions are difficult to enforce, and
publication of critical habitat descriptions and maps would make
Spiranthes more vulnerable and increase enforcement problems. All
involved parties and principal landowners are aware of the location and
importance of protecting this species' habitat. Habitat protection will
be addressed through the recovery process and through the Section 7
provisions of the Act. Therefore it would not now be prudent to
determine critical habitat for Spiranthes delitescens.
Lilaeopsis is not threatened by collecting and the Service knows of
no circumstance where the species is threatened by vandalism.
Therefore, critical habitat designation is prudent for this species.
Salamander collecting by bait dealers and anglers has been
identified as a Sonora tiger salamander threat and publication of
salamander localities rule could facilitate collecting. However, other
subspecies of A. tigrinum are readily available from numerous less
remote Arizona localities, collecting these other subspecies is legal,
and State law prohibits collecting and stocking salamanders in the
range of the Sonora tiger salamander. Thus, publication of critical
habitat localities is unlikely to substantially increase threats to the
Sonora tiger salamander. The Service finds the benefits of designating
critical habitat outweigh any risk of increased collecting and
determines that designation of critical habitat is prudent for the
Sonora tiger salamander.
Section 4(b)(2) of the Act requires the Service to consider
economic and other impacts of designating a particular area as critical
habitat. Information concerning probable impacts that would be
associated with designation of critical habitat for these two species
has not yet been fully assessed or analyzed. Efforts aimed at gathering
and analyzing such information are currently underway, but have not
been completed. Regulations at 50 CFR 424.12(a)(2)(i) specify that
critical habitat is not determinable when ``Information sufficient to
perform required analyses of the impacts of the designation is lacking
* * *'' The Service therefore finds that critical habitat for the
Huachuca water umbel and the Sonora tiger salamander is not now
determinable. When information becomes available and the review has
been completed, the Service intends to propose designation of critical
habitat for both species to the maximum extent prudent.
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 certain activities involving
listed species 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 the species or 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.
Two of the taxa in this proposal, the Sonora tiger salamander and
Lilaeopsis, occur on the Coronado National Forest. The latter species
also occurs on the Fort Huachuca Military Reservation managed by the
Department of Defense.
Examples of Federal actions that may affect the three species in
this proposal include--issuing mining permits, managing recreation,
road construction, livestock grazing, granting right-of-ways, stock
tank development and maintenance, and military activities. These and
other Federal actions would require formal section 7 consultation if
the action agency determines that the proposed action may affect listed
species. Development on private or State lands requiring permits from
Federal agencies, such as 404 permits from the U.S. Army Corps of
Engineers, would also be subject to the section 7 consultation process.
Private actions that are not Federally funded or permitted would
require a section 10(a)(1)(B) permit if implementation would result in
incidental take of Sonora tiger salamander.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered
plants. All trade prohibitions of section 9(a)(2) of the Act,
implemented by 50 CFR 17.61, apply. These prohibitions, in part, make
it illegal for any person subject to the jurisdiction of the United
States to import or export, transport in interstate or foreign commerce
in the course of a commercial activity, sell or offer for sale listed
species in interstate or foreign commerce, or to remove and reduce the
species to possession from areas under Federal jurisdiction. In
addition, for plants listed as endangered, the Act prohibits the
malicious damage or destruction on areas under Federal jurisdiction and
the removal, cutting digging up, or damaging or destroying of such
plants in knowing violation of any State law or regulation, including
State criminal trespass law. Certain [[Page 16846]] exceptions apply to
agents of the Service and State conservation agencies.
The Act and 50 CFR 17.62 and 17.63 also provide for the issuance of
permits to carry out otherwise prohibited activities involving
endangered plants under certain circumstances. Such permits are
available for scientific purposes and to enhance the propagation or
survival of the species. It is anticipated that few trade permits would
ever be sought or issued for Lilaeopsis or Spiranthes because these
species are not common in cultivation or in the wild.
The Act and implementing regulations set forth a series of general
prohibitions and exceptions that apply to all endangered wildlife. The
prohibitions codified at 50 CFR 17.21, 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 a 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 under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.22 and 17.23. 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 on listed plants and
wildlife and inquiries about prohibitions and permits may be addressed
to U.S. Fish and Wildlife Service. Branch of Endangered Species/
Permits, P.O. Box 1306, Albuquerque, New Mexico 87103 (telephone 505/
766-3972; facsimile 505/766-8063).
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 these species;
(2) The location of any additional populations of these 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 these species;
(4) Current or planned activities in the subject areas and their
possible impacts on these species; and
Final promulgation of regulations on these 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. Request 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 the State
Supervisor (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
A complete list of all references cited herein, as well as others,
is available upon request from the Arizona Ecological Services State
Office (see ADDRESSES section).
Authors
The primary authors of this proposed rule are Susan Rutman,
formerly of the Service's Arizona Ecological Services State Office, and
Jim Rorabaugh (see ADDRESSES section).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, 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 ``Amphibians,'' to the List of Endangered and
Threatened Wildlife to read as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate population
--------------------------------------------------- Historic range where endangered or Status When listed Critical Special
Common name Scientific name threatened habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Amphibians
* * * * * * *
Salamander, Sonora tiger Ambystoma tigrinum U.S.A. (AZ), Mexico..... Entire................. E NA NA
stebbinsi.
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 16847]] 3. Section 17.12(h) is amended by adding the
following two species in alphabetical order to the List of Endangered
and Threatened Plants to read as follows:
Sec. 17.12 Endangered and threatened plants.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species
--------------------------------------------------- Historic range Family Status When listed Critical Special
Scientific name Common name habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
Flowering Plants
* * * * * * *
Lilaeopsis schaffneriana Huachuca water umbel.... U.S.A. (AZ), Mexico..... Apiaceae............... E NA NA
ssp. recurva.
* * * * * * *
Spiranthes delitescens.. Canelo Hills ladies'- U.S.A. (AZ)............. Orchidaceae............ E NA NA
tresses.
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: March 29, 1995.
Mollie H. Beattie,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 95-8176 Filed 3-31-95; 8:45 am]
BILLING CODE 4310-55-M
