[Federal Register Volume 63, Number 110 (Tuesday, June 9, 1998)]
[Proposed Rules]
[Pages 31400-31406]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15333]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 12-Month Finding
for a Petition To List the Lesser Prairie-Chicken as Threatened and
Designate Critical Habitat
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
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SUMMARY: The Fish and Wildlife Service (Service) announces a 12-month
finding for a petition to list the lesser prairie-chicken (Tympanuchus
pallidicinctus) under the Endangered Species Act of 1973 as amended.
After review of all available scientific and commercial information,
the Service finds that listing this species is warranted but precluded
by other higher priority actions to amend the Lists of Endangered and
Threatened Wildlife and Plants. The lesser prairie-chicken is added to
the Service's candidate species list.
DATES: The finding announced in this document was made on June 1, 1998.
ADDRESSES: Data, information, comments, or questions concerning this
petition should be sent to the Field Supervisor, U. S. Fish and
Wildlife Service, 222 S. Houston, Suite A, Tulsa, Oklahoma, 74127. The
petition finding, supporting data, and comments are available for
public inspection, by appointment, during normal business hours at the
above address.
FOR FURTHER INFORMATION CONTACT: Jerry Brabander, Field Supervisor,
Oklahoma Ecological Services Field Office (see ADDRESSES section)
(telephone 918/581-7458 ext. 224, facsimile 918/581-7467).
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Endangered Species Act (Act) of 1973, as
amended (16 U.S.C. 1531 et seq.), requires that for any petition to
revise the Lists of Endangered and Threatened Wildlife and Plants that
contains substantial scientific and commercial information, the Service
make a finding within 12 months of the receipt of the petition on
whether the petitioned action is: (a) not warranted, (b) warranted, or
(c) warranted but precluded from immediate proposal by other pending
proposals of higher priority. Information contained in this notice is a
summary of the information in the 12-month finding, which is the
Service's decision document. When a petition to list a species is found
to be warranted but precluded, the species is designated a candidate
species. A candidate species is a taxon for which the Service has on
file sufficient information to support issuance of a proposed listing
rule. Section 4(b)(3)(C) requires that a petition for which the
requested action is found to be warranted but precluded be treated as
though it has been resubmitted on the date of such finding; a
subsequent finding is to be made on such a petition within 12 months of
the initial or previous finding. Notices of such 12-month findings are
to be published promptly in the Federal Register.
On October 6, 1995, the Service received a petition, dated October
5, 1995, from the Biodiversity Legal Foundation, Boulder, Colorado and
Marie E. Morrissey (petitioners). The petitioners requested that the
Service list the lesser prairie-chicken as threatened throughout its
known historic range in the United States, and that critical habitat be
designated as soon as needs of the species are sufficiently well known.
However, from October 1995 through April 1996, funding for the
Service's listing program was severely reduced or eliminated and the
Service was unable to act on the petition.
The Service made a 90-day finding that the petition presented
substantial information indicating that the
[[Page 31401]]
requested action may be warranted. The 90-day finding was announced in
the Federal Register on July 8, 1997 (62 FR 36482). In that notice,
additional information on the status, trend, distribution, and habitat
use of the species was requested by September 8, 1997, for use in a
status review. In response to a request by the Lesser Prairie-chicken
Interstate Working Group comprised of state agencies and other
interested parties, an additional 30-day period for submission of
information was announced in the Federal Register on November 3, 1997
(62 FR 59334).
The Service has reviewed the petition, the literature cited in the
petition, other available literature and information, and consulted
with biologists and researchers familiar with the lesser prairie-
chicken. On the basis of the best scientific and commercial information
available, the Service finds the petition is warranted but precluded by
work on other species having higher priority for listing.
The lesser prairie-chicken is in the Order Galliformes, Family
Phasianidae, subfamily Tetraoninae, and is recognized as a species
separate from the greater prairie-chicken (Tympanuchus cupido)
(American Ornithologist's Union 1957). Average length ranges from 38-41
centimeters (15-16 inches) (Johnsgard 1973). The plumage of the lesser
prairie-chicken is similar to that of the greater prairie-chicken,
although it is somewhat lighter and is characterized by alternating
brown and buff-colored barring. Males have long tufts of feathers on
the sides of the neck which are erected during courtship display. Males
also display yellow-orange eyecombs and reddish-purple air sacs during
courtship displays (Copelin 1963, Johnsgard 1983). Lesser prairie-
chickens were first described as a subspecies of the greater prairie-
chicken (Ridgway 1873) but were granted specific status in 1885
(Ridgway 1885). A discussion of lesser prairie-chicken taxonomy is
found in Giesen (1997).
Lesser prairie-chickens exhibit a lek mating system. Males gather
to display on leks at dusk and dawn beginning in late February through
early May (Copelin 1963, Hoffman 1963, Crawford and Bolen 1975). A
dominant older male occupies the center of the lek, while younger males
gather in outlying areas. Females arrive at the lek in early spring;
peak hen attendance at leks is during mid-April (Copelin 1963, Haukos
1988). The sequence of vocalizations and posturing of the dominant
male, termed ``booming,'' has been described by Johnsgard (1983) and
Haukos (1988).
After mating, the hen selects a nest site, usually 1-3 kilometers
(km) (0.6-2 miles (mi)) from the lek (Giesen 1994b), and lays an
average clutch of 10-14 eggs (Bent 1932, Taylor and Guthery 1980).
Second nests may occur when the first attempt is unsuccessful.
Incubation lasts 23-26 days, and young leave the nest within hours of
hatching (Coats 1955). Broods may remain with females for 6-8 weeks
(Ehrlich et al. 1988). Campbell (1972) estimated a 65 percent annual
mortality rate, and a 5-year maximum life span. Giesen (1997) provided
a comprehensive summary of lesser prairie-chicken breeding behavior,
habitat, and phenology.
The lesser prairie-chicken historically occupied areas of sand
sagebrush (Artemesia filifolia)--bluestem (Andropogon spp. and/or
Schizachyrium spp.) or shinnery oak (Quercus havardii)--bluestem
grasslands in portions of southeastern Colorado (Giesen 1994a),
southwestern Kansas (Schwilling 1955), western Oklahoma (Duck and
Fletcher 1944), the Texas Panhandle (Henika 1940, Oberholser 1973), and
eastern New Mexico (Ligon 1927). In Colorado and Kansas, the sand
sagebrush prairie community used by lesser prairie-chickens also
includes sand dropseed (Sporobolus cryptandrus), little bluestem
(Schizachyrium scorparium), switchgrass (Panicum virgatum), blue grama
(Bouteloua gracilis), and sideoats grama (Bouteloua curtipendula)
(Baker 1953, Taylor and Guthery 1980, Giesen 1994a). Most of the lesser
prairie-chickens in Kansas are found south of the Arkansas River in
sand sagebrush prairies similar to those in southeastern Colorado
(Sexson and Horak 1978).
In western Oklahoma, lesser prairie-chickens use sand sagebrush-
bluestem grasslands as well as the shinnery oak-bluestem grasslands,
dominated by sand bluestem (Andropogon halli), little bluestem, and
sand dropseed (Duck and Fletcher 1944, Copelin 1963). In Texas,
populations are confined almost exclusively to sandy ridges containing
shinnery oak and/or sand sagebrush, as well as tall grasses such as
sand bluestem, little bluestem, and switchgrass (Jackson and De Arment
1963, Litton 1978).
In the southeastern part of New Mexico, lesser prairie-chickens
exist in the shrub-dominated High Plains Bluestem habitat type in mixed
stands of tall grasses (i.e., sand bluestem, little bluestem) and
shinnery oak (Riley et al. 1993a). In northern New Mexico, lesser
prairie-chickens primarily used sand sagebrush rangelands dominated by
sand bluestem, little bluestem, and Indiangrass (Sorghastrum nutans),
with some yucca (Yucca spp.), shinnery oak, and mesquite (Prosopsis
spp.) (Taylor and Guthery 1980).
The diet of lesser prairie-chickens is dominated by vegetative
matter in autumn and winter, with insects increasing in proportion in
the diet during the summer months. Shinnery oak leaf galls, catkins,
leaves, and acorns may comprise 60-70 percent of the autumn and winter
diet (Davis et al. 1979; Riley et al. 1993b); fragrant sumac (Rhus
aromatica) and sand sagebrush also are important winter foods (Doerr
and Guthery 1980). When available, grain sorghum fields are often used
as winter food (Copelin 1963, Donaldson 1969). In New Mexico, green
vegetation constituted about 80 percent of the spring diet (Davis et
al. 1979). Insects (Acrididae, Tettigoniidae, and Membracidae)
comprised 55 percent of the summer diet of adults, and 99-100 percent
of the summer diet of juveniles (Davis et al. 1979, Davis et al. 1980).
Summary of Population Status
Little information is available on lesser prairie-chicken
populations prior to 1900. Litton (1978) suggested that there may have
been as many as two million birds in Texas alone prior to 1900. The
Service is not aware of any independent estimate to corroborate
Litton's claim, and the source or methodology behind his estimate is
unknown. However, in the early twentieth century, lesser prairie-
chickens were reportedly quite common throughout their range in
Colorado, Kansas, New Mexico, Oklahoma, and Texas (Bent 1932, Baker
1953, Bailey and Niedrach 1965, Sands 1968, Fleharty 1995). By the
1930s, extensive cultivation, overgrazing, and drought had begun to
cause the species to disappear from areas where it had been abundant
(Bent 1932, Baker 1953, Bailey and Niedrach 1965, Davison 1940, Lee
1950, Oberholser 1974). Lesser prairie-chicken abundance appeared to
fluctuate somewhat during the 1940s and 1950s (Copelin 1963, Snyder
1967, Crawford 1980), and by the early 1970s, the total fall population
may have been reduced to about 60,000 birds (Crawford 1980). By 1980,
the estimated total fall population was approximately 44,000 to 53,000
birds (Crawford 1980).
Each of the five State wildlife agencies provided the Service with
information regarding the status of the lesser prairie-chicken. Most
states collect data in the form of one or both of the following
indices--average lek size (i.e., number of males per lek); or density
of leks in a given area. The State of Kansas estimates density of birds
per square mile (sq mi). In general, each of
[[Page 31402]]
the State wildlife agencies believes that they are unable to provide a
precise estimate of lesser prairie-chicken population abundance in
their State. In the absence of bird density data, the number of active
leks over large areas was recommended as the most reliable index to
prairie grouse population trends (Cannon and Knopf 1981).
In Colorado, the lesser prairie-chicken has been listed as
threatened under State law since 1973. The total number of lesser
prairie-chickens counted on leks increased substantially between 1959
and 1990 as did survey effort. The Colorado Division of Wildlife
currently estimates a total of 800-1,000 lesser prairie-chickens in the
State (K. Giesen, pers. comm. August 26, 1997).
In Kansas, the lesser prairie-chicken is an upland game bird with a
legal harvest between December 1 and January 31. In the early part of
this century, lesser prairie-chickens were considered plentiful in the
sandhill and bunchgrass areas (Colvin 1914 as reported by Bent 1932),
and they remained abundant until the droughts of the 1930s (Schwilling
1955). Estimated fall population in 1979 was 17,000-18,000 birds
(Crawford 1980). Eight of 10 lesser prairie-chicken survey routes in
Kansas had a significantly declining trend of birds per sq mi (data
available from most routes from 1969-1995; R. Applegate, in litt.
August 8, 1996). In 1997, the rangewide average of 0.69 birds per 100
hectares (ha) (1.8 birds per sq mi) was not a statistically significant
decline over the 1996 average of 0.8 birds per 100 ha (2.2 birds per sq
mi) (Rodgers 1997).
In New Mexico the lesser prairie-chicken is an upland game bird,
although the hunting season was closed in 1996. Estimates of occupied
range in New Mexico over the last century suggest a pattern of decline
and increase, including reoccupation of former range (Ligon 1927,
Snyder 1967, Sands 1968). In the 1950s, the population was estimated at
40,000-50,000 (Sands 1968) and by 1972, at 6,000-10,000 birds (Taylor
and Guthery 1980 based on Campbell 1972). Survey data from 1971-1997
analyzed by the New Mexico Natural Heritage Institute show a clear
decrease after 1988. During the 1990s, much greater survey effort
continually failed to yield increased numbers of prairie chickens on
traditional lek sites on Bureau of Land Management (BLM) administered
property.
In Oklahoma, the lesser prairie-chicken is considered an upland
game bird, although the harvest season will be closed beginning with
the fall 1998 hunting season. Abundance estimates in Oklahoma also
suggest population fluctuations--in 1944, 15,000 birds were estimated
(Duck and Fletcher 1944); by 1956, only 2,500-3,000 (Summars 1956); and
in 1960, approximately 15,000 (Copelin 1963). By 1979, Cannon and Knopf
(1980) reported an estimated total of 7,500 lesser prairie-chickens. A
very rough estimate of 475 total lesser prairie-chickens in spring of
1995 was provided to the petitioner by the Oklahoma Department of
Wildlife Conservation (ODWC). Between 1968 and 1997, the mean number of
males per active lek ranged from a high of 16.5 in 1975 to a low of 4.6
in 1995. In both 1996 and 1997, an average of 6.8 males per active lek
was estimated. Between 1987 and 1997, the estimated density of leks
within occupied habitat ranged from a high of 0.13 leks per 100 ha
(0.33 leks per sq mi) in 1988 to a low of 0.024 leks per 100 ha (0.06
leks per sq mi) in 1997 (ODWC 1997).
In Texas, the lesser prairie-chicken is an upland game bird with a
legal harvest from October 18-19. Although Litton (1978) reported
estimates of 2 million birds in Texas prior to 1900, the source of this
estimate is unknown. By 1937, the population may have been reduced to
12,000 (Oberholser 1974). In 1967, the State of Texas believed the
lesser prairie-chicken population was of sufficient size to reinstate a
limited harvest, which had been closed since 1937. In 1979, the
population was estimated at 11,000-18,000 birds (Crawford 1980).
Between 1942 and 1986, the Texas Parks and Wildlife Department (TPWD)
annually estimated density of leks per 100 ha in two counties of the
Texas panhandle (Wheeler and Hemphill). During this time period,
density of leks in Hemphill County remained fairly stable, and averaged
0.083 leks per 100 ha (0.21 leks per sq mi). In 1997, density estimated
on this study area was 0.049 leks per 100 ha (0.13 leks per sq mi), 41
percent below the 1942-1986 average. In Wheeler County, the 1942-1985
average was 0.518 leks per 100 ha (1.35 leks per sq mi), and the 1997
estimate was 0.074 leks per 100 ha (0.19 leks per sq mi), 85.7 percent
lower than the 1942-1986 average (J. Hughes, in litt. August 26, 1997).
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 the lesser prairie-chicken are as
follows:
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Historical and Current Range
In the early twentieth century, lesser prairie-chickens were
reportedly common throughout their five-state range (Bent 1932, Baker
1953, Sands 1968, Fleharty 1995). Lesser prairie-chickens are currently
found within each of the five states, although their distribution
within those states has declined (Bent 1932, Taylor and Guthery 1980,
Giesen 1997).
The area originally occupied by lesser prairie-chickens was
estimated as 358,000 square kilometers (sq km) (140,000 sq mi), and by
1969 it was about 125,000 sq km (49,000 sq mi), due to wide-scale
conversion of native prairie to cultivated cropland (Taylor and Guthery
1980 based on Aldrich 1963). In 1980, occupied range was estimated at
27,300 sq km (10,700 sq mi), which represented a 78 percent decrease in
range since 1963, and a 92 percent decrease since the 1800s (Taylor and
Guthery 1980).
Colorado--It is likely that lesser prairie-chickens were resident
only in six counties prior to settlement (Giesen 1994a). Museum
specimens are known only from Baca and Prowers counties (Giesen 1994a).
At present, lesser prairie-chickens are known to be present in Baca,
Prowers, and Kiowa counties (Giesen 1994a).
Kansas--Lesser prairie-chicken historical range included 38
counties (Schwilling 1955, Figure 1), and they are currently known to
exist in 19 Kansas counties (R. Applegate, in litt. October 8, 1997).
Oklahoma--Lesser prairie-chickens historically occurred in 16
Oklahoma counties (Duck and Fletcher 1944). In 1943, lesser prairie-
chickens were located in nine counties, comprising an estimated range
of 10,143 sq km (3,962 sq mi) (Duck and Fletcher 1944). In 1963, they
were located in 12 counties, with an estimated range of 6,225 sq km
(2,432 sq mi) (Copelin 1963). By 1979, they were verified in 8
counties; isolated fragments totaled an estimated 2,791 sq km (1,090 sq
mi), a decrease of approximately 72 percent since 1944 (Cannon and
Knopf 1980).
At present, there are reports of lesser prairie-chickens occurring
in seven counties (ODWC 1997; R. Horton, ODWC, in litt. November 12,
1997; J. Shackford, Oklahoma Cooperative Fish
[[Page 31403]]
and Wildlife Research Unit, in litt. May 27, 1997). The estimated
occupied range in 1995 was 1,162 sq km (454 sq mi) (R. Horton, ODWC,
pers. comm. December 13, 1995), which would indicate a decrease of 89
percent since Duck and Fletcher's (1944) estimate.
Texas--The earliest systematic survey of lesser prairie-chickens in
the State was Henika (1940) (M. Peterson, TPWD and Wildlife, in litt.
October 17, 1997). At that time, range of the lesser prairie-chicken
encompassed portions of 20 counties (Henika 1940). In addition to those
counties, Oberholser (1974) reported that museum specimens exist for
five additional counties, although there is uncertainty as to whether
two of the five specimens were actually greater prairie-chicken and
Attwater's prairie-chicken (Tympanuchus cupido attwateri), respectively
(M. Peterson, in litt. November 12, 1997). Although Henika (1940) may
have reported the first systematic survey, Henika considered the
occupied range at that time to be a reduction of the historical range.
In 1989, the TPWD produced an occupied range map that encompassed
portions of 13 counties (Locknane 1992), with an estimated range of
5,732 sq km (2,239 sq mi) (A. Sansom, in litt. April 3, 1997); a net
loss of 793 sq km (310 sq mi) of occupied habitat had occurred between
1940 and 1989 (M. Peterson, in litt. October 17, 1997). In 1997, TPWD
reported that lesser prairie-chickens were found in 16 counties (K.
Mote, in litt. October 17, 1997).
New Mexico--In the 1920s and 1930s, the former range of the lesser
prairie-chicken in New Mexico was described as all of the sandhill
rangeland of eastern New Mexico, from Texas to Colorado, and west to
Buchanan in DeBaca County (Ligon 1927, Bent 1932, Snyder 1967). Ligon
(1927) mapped the breeding range at that time as encompassing portions
of seven counties, a small subset of what he described as former range.
In the 1950s and 1960s, occupied range mapped by Frary (1957) and
Snyder (1967) was more extensive, indicating reoccupation of some
areas. Presently, New Mexico Department of Game and Fish (NMDGF)
reports that lesser prairie-chickens are known in portions of seven
counties (B. Hale, NMDGF, pers. comm. October 6, 1997), and that they
have apparently been extirpated from 3,308 sq km (1,292 sq mi) of an
original range of 22,131 sq km (8,645 sq mi) (Bailey 1997).
Habitat Destruction
Conversion of native sand sagebrush and shinnery oak rangeland to
areas of cultivation is cited by many authors as an important factor in
the decline of lesser prairie-chickens (Copelin 1963; Jackson and
DeArment 1963; Crawford and Bolen 1976; Crawford 1980; Taylor and
Guthery 1980; Braun et al. 1994; Lesser Prairie-chicken Interstate
Working Group 1997). Between 1915 and 1925, many new acres of prairie
sod were plowed on the Great Plains to grow needed wheat (Laycock
1987). By the 1930s, Bent (1932) speculated that extensive cultivation
or overgrazing had begun to cause the species to disappear from
sections where it had been abundant. Because grain crops increased
winter food supply, the initial conversion of some native prairie to
cultivation may have been beneficial to the species. However, areas
with greater than 20-37 percent cultivation may be incapable of
supporting stable populations (Crawford and Bolen 1976). In the 1940s,
1970s, and 1980s, additional acres of previously unbroken grassland
were plowed (Laycock 1987).
Bragg and Steuter (1995) estimated that in 1993, only 8 percent of
the bluestem-grama association and 58 percent of the mesquite-
buffalograss association as described by Kuchler (1985) remained. The
remaining mixed-grass prairie vegetation differs from pre-settlement
conditions. The present grazing, fire, and water management regimes are
vastly different and less variable, cultivated cropland has been added,
and the amount of woodland habitat has expanded (Knopf and Samson
1997).
Recent loss of native rangeland within the range of the lesser
prairie-chicken was determined using the National Resources Inventory
(NRI) of the U. S. Department of Agriculture Natural Resources
Conservation Service (NRCS). The 1992 NRI Summary Report provided
estimates of change in rangeland acreage from 1982-1992 for each state.
When considered state-wide, each of the five states with lesser
prairie-chickens showed a decline in the amount of rangeland acreage
over that time period, indicating that loss of habitat may still be
occurring. However, estimates of rangeland from 1982-1992 for counties
specifically within lesser prairie-chicken range showed no
statistically significant change, possibly due to small sample size and
large variance estimates.
Habitat Modification (Grazing and Fragmentation)
Grazing has always been an ecological force within the Great Plains
ecosystem. The evolutionary history of the mixed-grass prairie resulted
in endemic bird species adapted to a mosaic of lightly to severely
grazed areas (Bragg and Steuter 1995, Knopf and Samson 1997). The
Service believes that areas of heavily, moderately, and lightly grazed
areas are necessary on a landscape scale. In some areas within lesser
prairie-chicken range, an insufficient amount of lightly grazed habitat
is available to support successful nesting (Crawford 1980; Jackson and
DeArment 1963; Davis et al. 1979; Taylor and Guthery 1980; Davies
1992). Uniform or widespread livestock grazing of rangeland to a degree
that leaves less than adequate residual cover remaining in the spring
is considered detrimental to lesser prairie-chicken populations (Bent
1932; Davis et al. 1979; Cannon and Knopf 1980; Crawford 1980; Bidwell
and Peoples 1991; Riley et al. 1992; Giesen 1994b), because grass
height is reduced below that necessary for nesting cover and desirable
food plants are markedly reduced. Superior cover at and around nests is
thought to increase nest success because nests are better concealed
from predators (Davis et al. 1979; Wisdom 1980; Riley et al. 1992;
Giesen 1994b). When grasslands are in a deteriorated condition due to
overgrazing, the soils have less water-holding capacity, and the
availability of succulent vegetation and insects is reduced. Thus, the
effects of overgrazing are likely exacerbated by drought (Davis et al.
1979; Merchant 1982).
In summary, livestock grazing is not necessarily detrimental to
lesser prairie-chickens. However, a level of grazing that leaves little
cover in the spring for concealment of prairie-chicken nests is
detrimental. In some areas, limited brush control may be warranted, but
widespread eradication of brush to increase forage for livestock can
result in a lack of shrub cover for lesser prairie-chickens which is
also detrimental. Because the lesser prairie-chicken depends on medium
and tall grasses that are preferred by cattle in regions of low
rainfall, its habitat is easily overgrazed (Hamerstrom and Hamerstrom
1961). To be favorable to lesser prairie-chickens, grazing management
must ensure that a diversity of plants and cover types remain on the
landscape (Taylor and Guthery 1980).
Because suitable habitat for lesser prairie-chickens has been lost
due to conversion to agriculture and modified through grazing practices
and other factors, much of the remaining suitable habitat is fragmented
(Crawford 1980; Braun et al. 1994). Fragmentation may exacerbate the
extinction process (Wilcove et al. 1986) through several mechanisms:
remaining fragments may be smaller than the necessary home range size
(Samson 1980), necessary
[[Page 31404]]
habitat heterogeneity may be lost, habitat between patches may house
high levels of predators or brood parasites, and the probability of
recolonization decreases as distance from nearest patch increases
(Wilcove et al. 1986; Knopf 1997). As a group, grouse may be relatively
intolerant of extensive habitat fragmentation due to their short
dispersal distances and other life history characteristics such as
specialized food habits and generalized anti-predator strategies (Braun
et al. 1994).
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
In the late 19th century, lesser prairie-chickens were subject to
market hunting (Jackson and DeArment 1963). Harvest has been regulated
since approximately the turn of the century (Crawford 1980). Giesen
(1997) summarized the history of regulated harvests in each of the
states: hunting seasons were closed in Colorado in the early 1900s; in
Kansas from 1903-1905, 1913-1916, 1927-1930, 1936-1940, 1944-1950, and
1953-1956; in Texas from 1937-1967; in New Mexico from the early 1930s
to 1948, 1950-1958, and 1996 through present; and in Oklahoma from
1916-1928, 1930, 1932, and 1934-1949. Currently, the lesser prairie-
chicken is classified as a game species in Kansas, New Mexico,
Oklahoma, and Texas, although the legal harvest is now closed in New
Mexico and Oklahoma.
The Service does not believe that overutilization through
recreational hunting is a primary cause of lesser prairie-chicken
population declines. However, when populations are small and
fragmented, they are vulnerable to local extirpations through many
mechanisms, including human harvest. The Service does not know if the
continental lesser prairie-chicken population has declined to the point
where recreational harvest could cause a significant decline at the
population level.
Braun et al. (1994) called for definitive experiments that evaluate
the extent to which hunting is an additive mortality factor at
different harvest rates and in different patch sizes. In the interim,
they suggested conservative harvest regimes for small or fragmented
populations, because fragmentation likely decreases the resilience of
populations to harvest. The Service concurs with this recommendation.
The effect of recreational observations of birds at leks is
unknown. These effects are likely to be minimal at the population level
if disturbance is minimized by observers remaining in vehicles or
blinds until the birds disperse from the lek after sunrise, and if
observations are confined to a limited number of total leks.
C. Disease or Predation
Giesen (1997) reported no available information on ectoparasites or
infectious diseases in lesser prairie-chickens, although several
endoparasites including nematodes and cestodes are known to infect the
species. In the spring of 1997, a sample of 12 lesser prairie-chickens
from Hemphill County, Texas, were captured and tested for the presence
of disease and parasites. No evidence of viral or bacterial diseases,
hemoparasites, parasitic helminths, or ectoparasites was found (J.
Hughes, TPWD, in litt. August 26, 1997). The significance of the
parasite infestations noted in the literature is unknown. The Lesser
Prairie Chicken Interstate Working Group (1997) concluded that while
density-dependent transmission of disease was unlikely to have a
significant effect on lesser prairie-chicken populations, a disease
that was transmitted independently of density could have drastic
effects.
Prairie falcons (Falco mexicanus), northern harriers (Circus
cyaneus), great-horned owls (Bubo virginianus), and coyotes (Canis
latrans) have been identified as predators of lesser prairie-chicken
adults and chicks (Copelin 1963; Davis et al. 1979; Merchant 1982;
Haukos and Broda 1989; Giesen 1994). Predators of nests and eggs also
include Chihuahuan ravens (Corvus cryptoleucus), striped skunks
(Mephitis mephitis), ground squirrels (Spermophilus spilosoma), and
bullsnakes (Pituophis melanoleucus), as well as coyotes and badgers
(Taxidea taxus) (Davis et al. 1979, Giesen 1997).
Predation on lesser prairie-chickens is especially important
relative to nest success. Nest success and brood survival of greater
prairie-chickens accounted for most of the variation in population
trends (Wisdom and Mills 1997). Thus, to have the greatest effect on
population growth, management for greater prairie-chickens should focus
on improving nest success and brood survival. To the Service's
knowledge, a similar analysis has not been completed for the lesser
prairie-chicken, but the Service expects that survival of young is
important for all prairie grouse. Bergerud (1988) concluded that
population changes in many grouse species are driven by changes in
breeding success; this conclusion was supported by an analysis of
Attwater's prairie-chicken (Peterson and Silvy 1994).
The community of prairie mammals has undergone a significant
reconstruction due to destruction of habitat, decimation of keystone
species and top predators, and the increase in generalist and
introduced animals (Benedict et al. 1996). Habitat generalist species
such as the coyote, red fox (Vulpes fulva), gray fox (Urocyon
cinereoargenteus), and raccoon (Procyon lotor) may all have increased
in population size or range size since European settlement (Bowles
1981; Jones et al. 1983; Caire et al. 1989; Benedict et al. 1996). The
initial reduction of large canids of the Great Plains may have been
responsible for an increase in medium-sized predators such as skunk,
raccoon, and fox, which are known to cause low duck nest success in the
northern Great Plains (Sargeant et al. 1984, Garrettson et al. 1996).
As habitat fragmentation increases, the effects of terrestrial nest
predators may increase (Braun et al. 1978). The Lesser Prairie-chicken
Interstate Working Group (1997) reported that two ongoing studies of
prairie grouse, in Kansas and Oklahoma, have shown a very high rate of
nest failure due to predators. However, the significance of nest
predation at the population level is not known.
D. The Inadequacy of Existing Regulatory Mechanisms
In 1973, the lesser prairie-chicken was listed as threatened in
Colorado under the State's ``Nongame and Endangered or Threatened
Species Conservation Act.'' In July of 1997, the NMDGF received a
formal request to commence an investigation into the status of the
lesser prairie-chicken within New Mexico. This request was the
beginning of the process for potential listing of this species under
New Mexico's Wildlife Conservation Act. Most occupied lesser prairie-
chicken habitat throughout its current range occurs on private land
(Taylor and Guthery 1980), where states have little authority to
protect the species or its habitat, with the exception of setting
harvest regulations.
The National Forest Management Act (NFMA, 36 CFR Ch. 11, Section
219.19), requires that certain species be identified as management
indicator species if their population changes are believed to indicate
the effects of management activities. According to the NFMA, planning
alternatives should be evaluated in terms of population trends of
management indicator species, and biologists from state and Federal
agencies should be consulted to coordinate planning. In Region 2 of the
Forest Service (USFS), the Pike and San Isabel National Forests, which
[[Page 31405]]
administers the Comanche and Cimarron National Grasslands, designates
the lesser prairie-chicken as a management indicator species. Its Land
and Resource Management Plan contains specific standards and guidelines
for lesser prairie-chicken habitat management. Revision of the current
Land and Resource Management Plan is scheduled to be completed in 1999
(J. Hartman, pers. comm. April 22, 1997).
The current standards and guidelines apply wherever lesser prairie-
chickens occur on these Grasslands (J. Hartman, in litt. April 25,
1997). The guidelines direct the USFS to: maintain range with a
diversity of plant forms, promote mid-seral to potential natural
community plant species, protect all lesser prairie-chicken leks from
surface disturbance at all times, protect nesting habitat from surface
disturbance from April 15-June 30, and limit livestock and wild
herbivore allowable forage use in lesser prairie-chicken habitat to 40
percent (J. Hartman, in litt. April 25, 1997). As stated in the Oil and
Gas Leasing Environmental Impact Statement for the Comanche and
Cimarron National Grasslands, no surface use is allowed in ``prairie
chicken dancing grounds and nesting areas'' between March 1 and June 1
(J. Hartman, in litt. April 25, 1997). Internal USFS recommendations
(USDA Forest Service 1995) to implement a specific habitat monitoring
plan to ensure that nesting habitat standards are met had not been
implemented as of December 1997 (S. Curry, USFS, pers. comm. December
1, 1997).
In Region 3 of the USFS, the Cibola National Forest, which
administers the Black Kettle, Kiowa, and Rita Blanca National
Grasslands, does not designate the lesser prairie-chicken as a
management indicator species and does not provide specific standards
and guidelines for lesser prairie-chicken habitat management. The Land
and Resource Management Plan is currently being revised, and the USFS
is considering: (1) making the lesser prairie-chicken an indicator
species; and (2) the implementation of grazing guidelines specific to
lesser prairie-chicken habitat needs. However, these decisions have not
been finalized (L. Cosper, USFS, pers. comm. January 13, 1998). Over
the past year, District Rangers of the Cimarron, Comanche, and Black
Kettle National Grasslands have been consulting with the State wildlife
agencies to refine nesting habitat recommendations and to develop
grazing standards (J. Hartman and D. Pieper, in litt. September 5,
1997).
The other Federal land occupied by lesser prairie-chickens is
administered by the BLM in New Mexico. The lesser prairie-chicken has
no official special status on land administered by the BLM (E.
Roberson, BLM, in litt. January 12, 1998). The majority of lesser
prairie-chicken habitat is within the Roswell Resource Area. In October
of 1997 the Roswell Approved Resource Management Plan and Record of
Decision were signed (BLM 1997a). Drilling and 3-D geophysical
exploration will not be allowed in lesser prairie-chicken habitat March
15-June 15 each year. During that period, other activities that produce
noise or involve human activity will not be allowed between 3:00 am and
9:00 am; this does not include normal, around-the-clock operations. No
new drilling will be allowed within 200 meters (m) (650 feet (ft)) of
all known leks, although exceptions will be considered for areas of no
or low prairie-chicken booming activity; unoccupied habitat, including
leks, as determined at the time of permitting; or in emergency
situations (BLM 1997a, App. 1). Because lesser prairie-chickens often
nest within a 3 km (1.9 mi) radius of a lek, restrictions on drilling
within 200 m will not protect all or even a majority of nesting
habitat.
Davis et al. (1979) were contracted by BLM to provide information
necessary to evaluate the effects of grazing on lesser prairie chicken
habitat needs. Although Davis et al. (1979) recommended reduction of
stock levels and construction of a series of livestock exclosures at
least 32 ha (80 acres (ac)) in size, it is not clear that these
recommendations were followed. In 1997 BLM reported the presence of
several 1 ha (2-3 ac) exclosures, one 40 ha (97 ac) exclosure, and a
proposed expansion of a 37 ha (91 ac) exclosure to 80 ha (195 ac) (R.
French, BLM, pers. comm. November 12, 1997; BLM 1997a).
In New Mexico, the BLM administers a total of 2,275 grazing
allotments, 290 of which have Allotment Management Plans in place to
guide livestock grazing management (BLM 1997b). Of the 415 grazing
allotments present in the Roswell Resource Area, 45 have existing
Allotment Management Plans. An estimated 3 new plans or revisions will
be completed each year. The Resource Management Plan states that
adjustments in livestock numbers or other changes will be considered
and implemented, if needed, to avoid conflicts with the management of
habitat for lesser prairie-chickens (BLM 1997a, p. 30). Stocking rates
may not be decreased if a change in grazing management (change in
season of use, pasture rest rotation, or Holistic Range Management) can
be used to meet the same goal (E. Roberson, in litt. January 12, 1998).
As a separate effort, Standards for Public Land Health and
Guidelines for Livestock Grazing are being developed for public lands
by the New Mexico Resource Advisory Council, and ``will be implemented
in the Roswell Resource Area to develop a more effective partnership
between the ranching industry and the BLM'' (BLM 1997a, p. 31). A draft
copy of the Standards and Guidelines provided to the Service indicated
that livestock grazing guidelines will be applied only after it is
determined that a site does not meet the specified standard (BLM
1997b). Site indicator interpretations and targets will be developed by
each BLM field office in conjunction with various rangeland interests
(BLM 1997b, p. 4). The Service noted that no mention was made of NMDGF
or Service participation in the development of these standards. In
addition, while the above-referenced language in the approved Resource
Management Plan discusses potential livestock adjustments to avoid
conflicts with lesser prairie-chicken habitat needs, no specific
proposals to do so were noted. Given that the lesser prairie-chicken is
not currently a Federal- or State-listed species, a regulatory
mechanism may not exist to ensure development of standards and
guidelines that favor lesser prairie-chicken habitat needs.
E. Other Natural or Human Made Factors Affecting Its Continued
Existence
Drought is considered a universal ecological driver across the
Great Plains (Knopf 1997). Infrequent, severe drought may cause local
extinctions of annual forbs and grasses that have invaded stands of
perennial species, and recolonization of these areas may be slow
(Tilman and El Haddi 1992). In this way, drought may impact lesser
prairie-chickens through its effect on seasonal growth of vegetation
necessary to provide nesting and roosting cover, food, and escape from
predators (Merchant 1982; Peterson and Silvy 1994; Morrow et al. 1996).
The sensitivity of lesser prairie-chickens to drought was discussed
by Crawford (1980) and Hamerstrom and Hamerstrom (1961). Home ranges
may be larger in drought years (Copelin 1963, Merchant 1982), and
recruitment may be less likely after drought years (Merchant 1982,
Morrow 1986, Giesen 1997). Along with other prairie grouse, this
species has a high reproductive potential in years of adequate
[[Page 31406]]
conditions. Thus, drought conditions are unlikely to be the sole
causative factor in long-term lesser prairie-chicken population
declines, unless the severity and/or frequency of drought has increased
in recent years.
To address this question, the Service reviewed available records of
the monthly Palmer Drought Severity Index (PDSI, Palmer 1965) which
takes into account precipitation, evapotranspiration, and soil-moisture
conditions (Alley 1985). Monthly PDSI values from January 1895 through
July 1997 were obtained for the climate divisions within the lesser
prairie-chicken's range. Review of the average PDSI for the months
March-August in each year reveals that while major droughts over the
last century are clearly observed in each climate division (1930s,
1950s), there does not appear to be an increase in the frequency or
severity of drought conditions over the last 10-15 years. Highs and
lows during that time are well within the range of variation
experienced over the last 100 years.
Female ring-necked pheasants (Phasianus colchicus) have been
documented parasitizing nests of several species, including greater
prairie-chicken (Vance and Westemeier 1979; Kimmel 1987; Westemeier et
al. 1989). Consequences of nest parasitism vary, and may include
abandonment of the host nest, reduction in number of host eggs, lower
hatching success, and parasitic broods (Kimmel 1987). Predation rate
may increase with incidence of parasitism (Vance and Westemeier 1979).
Further consequences may include the imprinting of the pheasant young
from the parasitized nest to the host species, and later attempts by
male pheasants to court females of the host species (Schein 1963,
Kimmel 1987). Male pheasants have been observed disrupting the breeding
behavior of greater prairie-chickens on leks (Sharp 1957, Follen 1966,
Vance and Westemeier 1979). In addition, pheasant displays toward
female prairie-chickens almost always cause the female to leave the lek
(Vance and Westemeier 1979). Thus, an attempt by a pheasant to display
on a prairie-chicken lek would completely disrupt the normal courtship
activities of prairie-chickens.
To our knowledge, no published reports of this disruption exist for
lesser prairie-chickens, although the Service has received anecdotal
reports from staff of the ODWC, the TPWD, and the Oklahoma Cooperative
Fish and Wildlife Research Unit. The Service considers competition with
and parasitism by pheasants another factor that may have affected
lesser prairie-chicken populations. This factor needs further
quantification to understand its relative impact on lesser prairie-
chicken populations.
Section 4(b) of the Act states that the Service may make warranted
but precluded findings only if it can demonstrate that: (1) An
immediate proposed rule is precluded by other pending proposals; and
that (2) expeditious progress is being made on other listing actions.
On September 21, 1983 (48 FR 43098), the Service published in the
Federal Register its priority system for listing species under the Act.
The system considers magnitude of threat, immediacy of threat, and
taxonomic distinctiveness in assigning species numerical listing
priorities on a scale of 1 to 12. The Service has determined that the
overall magnitude of threats to the lesser prairie-chicken throughout
its range is moderate, and that the threats are ongoing, thus they are
considered imminent. A listing priority of 8 has consequently been
assigned for the lesser prairie-chicken. The Service is making
expeditious progress on other, higher priority listing actions.
The Service's 12 month finding contains more detailed information
regarding the above decisions. A copy may be obtained from the Oklahoma
Ecological Services Field Office (see ADDRESSES section). If additional
data become available in the future, the Service may reassess the
listing priority for this species or the need for listing.
References Cited
A complete list of references cited in this notice is available
upon request from the Oklahoma Ecological Services Field Office (see
ADDRESSES section).
Author
The primary author of this document is Noreen E. Walsh, Oklahoma
Ecological Services Field Office (see ADDRESSES section).
Authority
The authority for this action is the Endangered Species Act (16
U.S.C. 1532 et seq.)
Dated: June 1, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 98-15333 Filed 6-8-98; 8:45 am]
BILLING CODE 4310-55-P
