ATTWATER’S PRAIRIE CHICKEN
RECOVERY PLAN
1993
ATTWATER’S PRAIRIE CHICKEN
(Revised)
RECOVERY PLAN
(Original Approved: Deceuber 12, 1983)
Prepared by the Attwater’s Prairie Chicken Recovery Team
Nova J. Silvy, Leader
Departuent of Wildlife and Fisheries Sciences
Texas A&N University
College Station, TX
Dennis L• Brown
Texas Parks and Wildlife Department
Victoria, TX
Stephen E. Labuda,
U.S. Fish and Wildlife
Eagle Lake, TX
Jr.
Service
James G. Teer
Welder Wildlife Foundation
Sinton, TX
Dennis Williams
O‘ Conrior Brothers Ranches
Victoria, TX
for
Region 2
U.S. Fish and Wildlife Service
Albuquerque, New Mexico
Approved:
Date: 5~ J~fc~
DISCLAIMER
Recovery plans delineate reasonabl actions which are
believed to be required to recover and/or protect listed
species. Plans are published by the U.S. Fish and Wildlife
Service, sometimes prepared with the assistance of recovery
teams, contractors, state agencies, and others. Objectives
will be attained and any necessary funds made available
subject to budgetary and other constraints affecting the
parties involved, as well as the need to address other
priorities. Recovery plans do not necessarily represent the
views nor the official positions or approvals of any
individuals or agencies involved in the plan formulation,
other than the U.S. Fish and Wildlife Service. They represent
the official position of the U.S. Fish and Wildlife Service
Qfljy after they have been signed by the Regional Director or
Director as aDproved. Approved recovery plans are subject to
modification as dictated by new findings, changes in species
status, and the completion of recovery tasks.
Costs and task duration as listed in Part II are
estimates. Duration of some research tasks are unknown
because they are experimental in nature and it is difficult to
predict the time required to complete the task or to attain
required data sets for statistical analysis. Costs of some
management tasks are uncertain because they involve activities
for which there exists no previous cost experience. Cost
estimates include estimated expenditures for all involved
agencies and groups and current budgeted amounts as well as
additional dollars needed to accomplish full recovery.
ii
LITERATURE CITATIONS
Literature Citations should read as follows:
U.S. Fish and Wildlife Service. 1992. Attwater’s Prairie
Chicken Recovery Plan. Albuquerque, NM. vii + 48 pp.
Additional copies may be purchased from:
Fish and Wildlife Reference Service:
5430 Grosvenor Lane, Suite 110
Bethesda, MD 20814
301/492—6403
or
1—800—582—3421
The fee for the plan depends on the nuniber of pages.
iii
AcKNOWLEDGEMENTS
Several individuals have provided substantial input to the
recovery team in preparation of the originally approved plan
and this revision. Attwater Prairie Chicken National Wildlife
Refuge staff provided logistical and technical support in the
preparation of both documents. Royce W. Jurries, Texas Parks
and Wildlife Department, continues to provide valuable input
both in plan preparation and implementation. Others providing
input regarding rangewide habitat assessment include Fred
Smeins, Lloyd B. McKinney, and Marcus Peterson of Texas A&M
University. Participants at the 2nd Annual Attwater’s Prairie
Chicken Workshop in Victoria, Texas also provided input on
proposed revisions.
iv
EXECUTIVE SUMMARY
Current SDecies Status: The Attwater’s prairie chicken (APO)
is currently listed as endangered. Historically, an estimated
1 million APC’s occupied over 6 million acres of coastal
prairie habitat. In 1992, an estimated 456 individuals
remained in 4 populations located in 5 Texas counties. If
current rates of population decline continue, the APC will be
extinct by the year 2000.
Habitat Requireuents and Limiting Factors: The APC once
inhabited coastal prairie grasslands of Louisiana and Texas.
Habitat loss, due to range degradation, agriculture, and urban
expansion, is the primary factor contributing to its decline.
Recovery Objective: Delisting
Actions Needed
:
1. Acquire 22,000 acres of habitat through fee simple
acquisitions or easements (from willing
sellers/participants only). Protect and restore an
additional 40,000 acres of prairie grasslands through
extension and cooperative efforts.
2. Increase public outreach efforts to raise the public’s
awareness of this species and its problems.
3. Encourage and coordinate legislative and regulatory
programs to provide private landowners incentives to
maintain endangered species habitat on their properties.
4. Implement captive propagation and reintroduction programs.
5. Determine limiting factors and their interactions.
Costs ($000’s):
Year Need 1 Need 3 Need 4 Need S
1993 12,655 370 75 245 450
1994 6,663 8,370 75 245 450
1995 6,663 8,370 75 245 450
1996 1,663 370 75 245 450
1997 1,663 370 75 245 450
1998 1,663 370 75 245 450
1999 1,663 370 75 245 450
2000 2,155 540 75 205 450
Total 34,296 18,960 600 1,960 3,600
Date of Recovery: Downlisting could be initiated by the year
2000, if recovery criteria are met.
v
TABLE OF CONTENTS
DISCLAIMER
LITERATURECITATIONS
ACKNOIUIJEDGE1’1EN~PS
EXECUTIVESUNMARY
. . . iii
iv
. . . . v
LISTOFFIGURESANDTABLES
I. INTRODUCTION AND BACKGROUND .
A. TAXONOMIC CLASSIFICATION AND DESCRIPTION
B. DISTRIBUTION AND POPULATION ESTIMATES
C. HABITAT/ECOSYSTEM
D. LIFE HISTORY/ECOLOGY
E. REASONS FOR LISTING
F. CONSERVATION MEASURES
G. STRATEGYOFRECOVERY
II. RECOVERY
A. OBJECTIVESANDCRITERIA. . . . . .
. . . vii
. . . . 1
1
1
5
7
. . . . 9
12
18
B. NARRATIVE OUTLINE FOR RECOVERY ACTIONS ADDRESSING
~EATS
C . LITERATURE CITED . . . .
III. IMPLEMENTATION SCHEDULE
IV. APPENDIX I. COMMENTS .
19
19
20
32
36
41
ii
vi
ATTWATER’S PRAIRIE CHICKEN RECOVERY PLAN
I. INTRODUCTION AND BACKGROUND
A. TAXONOMIC CLASSIFICATION AND DESCRIPTION
The Attwater’s prairie chicken (TvmDanuchus cuDido
attwateri) (APC) was listed as endangered on March 11, 1967
(32 FR 4001) when about 1,070 birds were thought to remain in
the wild. It was described by Bendire (1894) as follows:
Smaller than T. americanus [greater prairie chicken],
darker in color, more tawny above, usually with more
pronounced chestnut on the neck; smaller and more
tawny light colored spots on the wing coverts, and
much more scantily feathered tarsus, the latter never
feathered down to the base of toes, even in front; a
broad posterior strip of bare skin being always
exposed, even in winter, while in summer much of the
greater part of the tarsus is naked In
weight, the APC is not perceptibly lighter than the
greater prairie chicken (T. ~. Dinnatus). Physical
—~ differences between the Attwater’s and the greater prairie
chicken are minor. However, smaller measurements of wing,
tail, bill, and total length and differences in general
ruddiness and buffiness of the underparts are characteristic
and can be used to separate the APC as a subspecies (Lehiuann
1941).
B. DISTRIBUTION AND POPULATION ESTIMATES
Historically, an estimated 1 million APC occupied some 6
million acres (2.4 million ha) of coastal prairie grasslands
from southwestern Louisiana to the Nueces River in Texas
(Lehmann 1941, 1968) (Fig. 1). In 1937, when the first in
depth study was conducted, this subspecies had become
extirpated in Louisiana, and approximately 8,700 remained in
Texas. By 1992, 4 Attwater’s populations remained in 5 Texas
counties (Fig. 1). Since approval of the original recovery
plan, the APC has become extirpated from Aransas, Fort Bend,
and Goliad counties.
Refugio—Goliad—Aransas PoDulation
:
Seventy-two percent of the rangewide APC population was
located in Refugio County during 1992 (Table 1). In Refugio
County, APC populations have declined from 838 birds in 1984
1
Corpus
christi
•1
N
100
-I
by Attwaters prairie
Galveston
0 25 50
+ +
MILES
Figure 1. Boundaries of counties historically occupied
chie”an and present range (shaded).
)
LIST OF FIGURES AND TABLES
Ficrure Paae
1 Boundaries of counties historically occupied by
Attwater’s prairie chickens and present range
(shaded) 2
2 Population and projected trend of Attwater’s prairie
chicken,1972—1999 10
3 Attwater Prairie Chicken National Wildlife Refuge. . 14
4 Essential habitat in Austin and Colorado counties,
Texas. 24
5 Essential habitat in Galveston County, Texas 25
6 Essential habitat in Goliad, Refugio, and Aransas
counties, Texas. 26
7 Essential habitat in Victoria County, Texas. . . . . 27
Table Pacre
1 Attwater’s prairie chicken population estimates by
Texas counties 3
vii
)
Table 1. Attwater’B prairie chicken population estimates by Texas county.
County
Population estimates
19921967 1981 1983 1985 1987 1989 1991
Aransas 0 20 22 16 10 6 2 0
Austin 200 234 292 114 150 46 56 48
Brazoria 0 20 0 0 0 0 0 0
Calhoun 10 0 0 0 0 0 0 0
Chambers 10 0 0 0 0 0 0 0
Colorado 175 184 320 246 242 90 70 50
FortBend 35 44 54 32 16 4 0 0
Galveston 130 110 66 36 38 16 30 26
Goliad 75 100 84 78 16 4 8 0
Harris 120 4 0 0 0 0 0 0
Jefferson 10 0 0 0 0 0 0 0
Refugio 175 658 646 810 582 246 310 330
Waller oa 0 0 0 0 0 0 0
Wharton 40 0 0 0 0 0 0 0
Victoria 2Q 112 94 20 8
TOTALS 1,070 1,438 1,596 1,426 1,108 432 482 456
a~ small population of
1970—77.
10-30 APC’s was observed in Wailer County during
3
to 330 birds in 1992. Much of this loss is attributed to a 3year
drought that ended in 1991.
Currently, no APC remain in Aransas County (Table 1).
Habitat management initiated in 1976 on the Tatton Unit of the
Aransas National Wildlife Refuge had helped to maintain a
resident population there. However, brush invasion on the
refuge and adjoining private lands has caused a continued
decline in APC numbers on the Tatton Unit.
Eight APC existed in Goliad County during 1991, but none
were observed on booming grounds in 1992. Historically,
dramatic swings have been observed in Attwater’s numbers in
Goliad County (Table 1). For example, Lehiuann (1941) reported
only 4 birds in Goliad County during his 1937 census, whereas
486 birds were observed there during the 1974 census of this
county. It is hypothesized that sandier soils of Goliad
County are more susceptible to drought conditions such as
occurred in the 1930’s and the 1980’s. However, when these
soils receive high rainfall such as during and after a
hurricane, they provide high quality grassland cover required
by prairie chickens. Conversely, during periods of high
rainfall, the poorly drained soils of Refugio and Aransas
counties become less suitable for prairie chickens.
Therefore, populations in these 3 contiguous counties appear
to be intertwined. Lehinann (1968) and Lawrence and Silvy
(1980) also referred to APC in these 3 counties as a single
population.
This relationship was apparently expressed in years
following hurricane Beulah, which occurred in 1967.
Populations in Goliad County increased following Beulah, and
were as great or higher than those in Refugio County from
1972-1974. On the other hand, the Refugio County population
crashed following Beulah (Lehmann 1968).
Austin—Colorado Population
:
The next largest APO population currently exists in Austin
and Colorado counties with a population estimate of 98 birds
(Table 1). This represents 22% of the rangewide population.
The Attwater Prairie Chicken National Wildlife Refuge, located
in Colorado County, provides relatively stable habitat for
this population. However, population estimates for this area
have declined from 360 in 1985 to its current (1992) level.
As was the case rangewide, severe drought conditions during
the late 1980’s resulted in drastic reductions in habitat
quality.
4-
Galveston County Population
:
The Galveston County 1992 estimate was 26 birds, or 6% of
the total population (Table 1). All of this population
occurred on a 1,730—acre ranch (700 ha) near Texas City. This
habitat is surrounded by Galveston Bay, petrochemical, and
urban development, making prospects for its long—term
existence extremely tenuous.
Victoria County PoDulation
:
The Victoria County 1992 population estimate was only 2
individuals, a decline of 98% since 1967 (Table 1). This
population is in imminent danger of becoming extirpated.
Invasion of the prairie by running live oak (Ouercus
virginiana), huisache (Acacia farnesiaria), and mesquite
(~1~j~ alandulosa), overgrazing, increased rice cultivation,
and urban expansion of the city of victoria have all
contributed to the decline of this population.
C. HABITAT/ECOSYSTEM
The historic habitat of Attwater’s prairie chicken was the
gulf coastal prairies of what is now Louisiana, Texas, and
possibly Tamaulipas (based on historical records of “prairie
— chickens” (species not identified) from Brownsville, Texas).
This broad belt of plains and marshes interlaced with wooded
streams supported a broad variety of plant and animal life.
Examples of larger mammals which contributed to this
biodiversity were gulf—coast hog—nosed skunk (Conepatus
mesoleucas), red wolf (Canis r~afjag), pronghorn (AntilocaDra
americana), plains bison (~j~gn bison), and Coushatta and
Karankawa Indians. Other bird species included tundra swans
(Cygnus columbianus), wood storks (Mvcteria americana), Eskimo
curlews (H~njj~ borealis), black terns (Childonias njg~r),
whooping cranes (~u~ americana), Carolina parakeets
(Conuropsis carolinensis), peregrines (Falco Derearinus)
prairie (Falco mexicanus) and Aplomado falcons (Falco
femoralis), bald eagles ~ leucocephalus), burrowing
owls (kL1~n~ cunicularia), short—eared owls (&~.i~ flammeus)
and a host of neotropical migrants, such as the dickcissel
(Spiza americana). Smaller vertebrates included species such
as the Houston toad (~a~ houstonensis) and Texas horned
lizard (Bb~yn~.Qmk ~n3a~J~n).
Maintenance of native gulf coastal prairie habitat is
essential for the survival of the APC (Lehmann 1941, Cogar et
al. 1977, Horkel 1979). Vegetation comprising APC habitat has
3 basic components: species composition, height, and density.
5
Obstruction of vision (OV) (Robel et al. 1970) will be used as
an index to vegetation density in this discussion.
Several types of cover are used throughout the year to
meet APC life requisites. However, Droperlv urazed native
prairie grasslands in good to excellent range condition (i.e.,
> 50% climax grass species composition) generally provide all
APC habitat requirements. These grasslands are dominated in
the climax community by perennial bunchgrass species such as
little bluestem (Schizachyrium scoDariulo), Indiangrass
(Sorghastrum nutans), switchgrass (Panicum virgatum), and big
bluestem (Andropogon gerardii)
.
In terms of specific structural characteristics, light
cover (< 25 cm height, < 1.5 din OV), artificially maintained
short grass areas (e.g., mowed rights—of—way), and hardpan
areas are used for courtship, feeding, and avoidance of
moisture during heavy dew or after rains (Lehmann 1941, Horkel
1979, Morrow 1986). Grasslands with light to medium—light
cover (25-40 cm height, 1-2 dm OV) are used for roosting and
feeding by adults and broods (Lehmann 1941, Horkel 1979,
Morrow 1986). Eighty-two percent of the roost forms found by
Cogar et al. (1977) were in native prairie grasslands of this
structure. Medium to heavy cover (40-60 cm height, 1.5-3 din
OV) is used for nesting, loafing, feeding, and escape cover.
Heavy cover (>60 cm, >3 din OV) is generally avoided, but is
used as protection from inclement weather and predators
(Lehmann 1941, Cogar et al. 1977, Morrow 1986). Cover that
consist of significant amounts of trees or brush is usually
avoided.
Nests are generally located in clumps of grass with OV’s
averaging 2.1-2.8 dm (Cogar et al. 1977, Lutz 1979, Lawrence
1982, Morrow 1986). It is important that grass cover between
these clumps be relatively open to facilitate movement by hens
and especially young chicks. Grassland habitat with OV’s
ranging from 0.5-3.0 din, and averaging approximately 1.7 dm
appear to provide the proper interspersion of grass clumps and
open areas needed for nesting and early brood cover (Attwater
Prairie Chicken National Wildlife Refuge, unpubi. data).
Brood cover should have sufficient canopy to provide shade
during summer, but be open enough at ground level to allow
uninhibited chick movement (Lehmann 1941, Kessler 1978). Forbdominated
areas often provide appropriate structure for brood
habitat, and typically support high insect populations which
constitute the bulk of the chick’s diet (Jones 1963).
Morrow (1986) found that broods used grassland habitats of
moderate density (2 din OV) early in the brooding period (prior
6
to 15 June), and more open habitats (0.5-1 din OV) during the
latter half of the brooding period.
Diversification within the coastal prairie grassland is
required so that all APC cover requisites are readily
available within its home range (Lehmann 1941, Cogar et al.
1977). Historically, minor variations in topography and soil
type were responsible for habitat interspersion (Lehinann
1941). However, on relatively small, isolated areas
characteristic of today’s APC habitat, active management is
often necessary to produce the required habitat interspersion.
Management practices which can be used to achieve and maintain
the desired habitat include proper grazing (i.e., use of
grazing systems and intensities such that grassland
communities are maintained in good to excellent range
condition) and prescribed fire (Chainrad and Dodd 1972, Cogar
et al. 1977, Morrow 1986).
D. LIFE HISTORY/ECOLOGY
Food Requirements
:
Potential food sources for APC vary by season, location,
and availability. Lehzaann (1941) identified 50 species of
plants and 65 species of insects as food sources. Cogar
(1980) identified foliage from 56 plant species, seeds from 19
species, and remains from 12 families of insects in adult APC
droppings.
Native plants, especially forbs, are the most important
food source for adult APC (Lehiuann 1941, Kessler 1978, Cogar
1980). APC’s are mostly herbivorous, eating more green foliage
and flowers than seeds or insects (Cogar 1980). However,
Lehinann (1941) found that seeds and seed pods comprised over
50% of the diet. Ruellia (Ea~i].i~~ sp.) is an important
component of the APC diet (Lehmann 1941, Cogar 1980). Other
species commonly found include foliage of yellow falsegarlic
(Nothoscorduin bivalve), upright prairie—conef lower (B~U.k±~
~n~ri~), Leavenworth vetch (yj~j.~, leavenworthii)
,
stargrass (kjy~Q~jx sp.), bedstraw (~12JJAn sp.), doveweed
(~r~n sp.), and perennial ragweed (h~krQaiA psilostachva
)
(Lebmann 1941, Cogar 1980). Kessler (1978) found that grass
and grass-like plants were present in the diet throughout the
year.
Seed use, including those of cultivated crops, is greatest
during fall and winter (Lebinann 1941, Kessler 1978, Cogar
1980). Seeds of cultivated crops used by APC include peanuts,
hegari (haygrazer), rice, corn, milo, soybeans, and mung beans
(Lehinann 1941, Kessler 1978, APCNWR unpubl. data). However,
7
due to potentially lethal levels of aflatoxins commonly
present in peanuts and corn, these crops are not recommended
for APC management (APCNWR unpubl. data). Cogar (1980) found
little use of nearby milo fields.
Insects are most prevalent in the APC diet during summer
and fall (Lehmann 1941, Kessler 1978, Cogar 1980). Kessler
(1978) found that insects comprised 71% of the diet in June.
Cogar (1980) found greatest insect use in autumn (21%).
Lehniann (1941) found insects to be extremely important in the
diet of APC chicks.
Free water has not been established as a dietary
requirement for prairie chickens during normal rainfall
conditions (Lehinann 1941).
Reproductive Recruirements
:
Prairie chicken breeding activity occurs on or near leks.
A lek or booming ground is an area typically used
traditionally as display grounds. Males gather on these areas
in early morning and late evening to establish individual
territories and to attract females. Attendance is sporadic in
the fall (October-November), but attendance and intensity of
territorial defense increases by late winter (January). In
early spring (late February - early March), females visit
booming grounds and select a male to mate with. Studies on
greater prairie chicken have shown that males occupying
territories near the center of the lek are generally the most
dominant, and usually perform the majority of copulations
(Robel 1970). After the female has mated, she leaves the
booming ground to initiate egg laying. She does not return to
the booming ground to mate again unless her nest is
subsequently destroyed. A detailed description of behaviors
and vocalizations associated with booming grounds is provided
by Lehinann (1941).
Booming grounds vary in size from about one—eighth acre to
several acres. They may be naturally occurring short grass
flats or artificially maintained areas such as roads, airport
runways, oil well pads, and drainage ditches (Horkel 1979).
Active booming grounds are usually in close proximity to
stands of midgrass habitat (Horkel 1979). Due to the large
number of artificially maintained areas currently available
within the APC’s range, sufficient booming areas are generally
available to all males (Horkel 1979). However, leks found on
such areas are sometimes less stable than ancestral leks. For
example, Kessler (1978) found that recently established
booming grounds on fallow rice fields had poor territorial
hierarchy when compared to ancestral grounds. Similarly,
8
Horkel and Silvy (1980) found that leks formed on narrow,
linear areas such as roads and pipeline rights—of—way were
less stable than the more typical circular—shaped leks.
Breeding commences in late February, peaks in early March,
and gradually decreases through April and early May (Lutz
1979). Typically, nests are found in native prairie
grasslands within 1.6 km of a booming ground (Horkel 1979).
Kessler (1978) and Jurries (1979) found a small number of
nests in fallow rice fields, although these nests were
generally unsuccessful.
Horkel (1979) reported that clutch size ranged from 4-15
eggs. The earliest date reported for initiation of incubation
was 1 April (Horkel 1979), and the latest initiation of
incubation was the 3rd week in May (Morrow 1986). Hatching
dates ranged from 24 April (Horkel 1979) to the third week in
June (Morrow 1986). Data from Lebinann (1941), Brownlee (1973—
74), Horkel (1979), Lutz (1979), and Morrow (1986) indicated
that APC nest success ranged from 15.8—42.0%, and averaged
31.2% Nest predators include skunks (Menhitis n~pkliZ.i~,
~pilgga1~ pi rii~), opossum (~i~21pLii~ virginianus), raccoon
~ 2.Q~Q~j, coyote (~ni~ latrans), snakes, and domestic
dogs and cats. Heavy precipitation during nesting and broodrearing
seasons can result in poor reproductive success and
subsequent low populations (Lehmann 1941).
The first weeks after hatching, are typically spent in
grasslands near the nest (Lehmann 1941). Starting about 4—6
weeks after hatching, broods use more open habitats associated
with midgrass nesting cover (Cogar et al. 1977, Horkel 1979,
Morrow 1986). Mortality of broods is typically high. Lehmann
(1941) observed a 50% mortality by 4-6 weeks, and Morrow
(1986) observed a 66% mortality of brood units by 8 weeks.
Morrow (1986) discussed the importance of interspersing
appropriate brood habitats with quality nesting cover as a
possible method for reducing mortality associated with brood
movements.
E. REASONS FOR LISTING
The number of APC’s has decreased from an estimated 8,700
birds in 1937 (Lehmann 1941) to 456 birds in spring 1992.
This represents a 95% decline in numbers since 1937 and
extirpation from 14 counties. If past trends continue, it is
projected that the APC will become extinct by the year 2000
(Fig. 2).
9
2,500
(I)
~ 2,000
(0
a)
0
.~ 1,500
“Em
i
~) 1,000
9I Urn
0
a)
a)
in. 500
m
0
Year
Figure 2. Population and projected trend of Attwater’s prairie
chic’ 1972-1999.
U
U
U
U
U.
U
U
U
q,bI q~~O#iYo
Habitat loss is the greatest threat to existing APC
populations. Agriculture, urban and industrial expansion,
invasion of prairie habitat by woody species, and overgrazing
have resulted in a dramatic decline in the tallgrass prairie
habitat required for survival of the Attwater’s. By 1979,
only 1.2 million acres (486,000 ha) of coastal prairie
remained out of the approximately 7 million acres that
originally existed (Jurries 1979). However, significant
portions of this 1.2 million acres were probably salt marsh
grasslands which were historically of marginal quality for
prairie chickens (Lehmann 1941). Some grasslands farther
inland were probably of insufficient quality to support
prairie chickens due to overgrazing, brush encroachment, and
habitat fragmentation. In 1937, Lehmann (1941) estimated that
the Attwater’s were found on only 460,000 acres of suitable
range. By 1967, APC were found on approximately 234,000 acres
of acceptable habitat (Lehiuann 1968).
Currently, less than 198,000 acres (80,200 ha) of suitable
habitat remain. Thi decline represents a 97% loss of habitat
within APC historic ~ange, and a 57% loss since 1937. The
impacts of long-term habitat declines have been further
accentuated by droug~1t in recent years. Drought led to
drastic overgrazing~n some ranges that ordinarily provided
suitable habitat. lb is imperative that habitat conditions be
improved on both exi3ting public and privately owned lands if
the APC is to be ret~ieved from the brink of extinction.
In the near futu
habitat for the APC
Goliad, and Refugio
Galveston County pro
and industrial expan
Houston, Texas metro
population resides i
and disturbance in t
the APC population s
consequences.
Although habitat
relatively stable in
Colorado and Victori
threats in the near
National Wildlife Re
stable habitat; howE
County) and on priv8
declined drainatical J
As long as rice
Colorado County, anc
re only 3 geographic areas will provide
(Austin and Colorado counties; Aransas,
zounties; and Victoria County). APC in
~ably will disappear due to urbanization
lion associated with growth of the
politan area. The land on which this
~ currently for sale. Habitat alteration
his area could cause drastic changes in
tability and lead to disastrous
conditions are expected to remain
Refugio and Goliad counties, the Austina
County populations will face major
future. The Attwater Prairie Chicken
fuge is expected to maintain relatively
ver, APC numbers on the refuge (Colorado
te land in adjacent Austin County have
y in recent years.
continues to be the dominant cash crop in
to a lesser extent in Austin County,
11
further expansion of this population is doubtful unless
satellite areas of nesting habitat can be developed. Section
6 projects recently initiated by the Texas Parks and Wildlife
Department (TPWD) to restore nesting habitat in Austin County
offer promise for improved habitat conditions in the near
term.
The Victoria County population consists of an estimated 2
birds and may not survive until the proposed second refuge can
be obtained in Victoria County. Section 6 monies are
currently being used by TPWD to reduce grazing pressure on
properties supporting this population. Although these efforts
may be too late to save the existing population, such efforts
will pave the way for future reintroduction efforts.
In addition to habitat loss, predation of adults, young,
and/or nests by some wild and feral animals negatively impact
some populations, especially those that occupy degraded
habitats. The potential also exists for competition with
geese for winter food supplies. Nest parasitism by ring—
necked pheasants (Phasianus ~~J1ii~ia~), which have been
unsuccessfully introduced periodically by private individuals
within APC range, have caused significant problems for greater
prairie chicken recovery efforts in Illinois (Westemeier
1986). The role of parasites, diseases, and genetic anomalies
in the population dynamics of increasingly fragmented APC
populations is not known, but must be considered as potential
limiting factors.
F. CONSERVATION MEASURES
Until recently, APC conservation measures consisted of
annual rangewide population censuses, public land management,
and research on APC life history and management. Failed
attempts have been made at captive propagation and transplants
of APC’s from one area to another. Beginning in 1990, more
emphasis was placed on providing technical assistance and
financial incentives to private landowners for APC management.
PoDulation Census
:
Annual population censuses have been conducted rangewide
in a cooperative effort by TPWD, the Service, and Texas A&M
University since 1972. Males are counted during spring on
historical booming grounds and, assuming a 50:50 sex ratio,
numbers are doubled to produce an estimate of the total
population. Historical booming grounds are surveyed, and
attempts are made to locate new or previously unknown grounds.
12
Public Land Manaciement
:
Management programs for the APC began in the inid—1960’s
with the purchase of prairie chicken habitat in Colorado
County, by the World Wildlife Fund-U.S., and a private
donation to the U.S. Fish and Wildlife Service of chicken
habitat adjoining Aransas National Wildlife Refuge.
Two national wildlife refuges (Attwater Prairie Chicken
and Aransas National Wildlife Refuges) currently have
management programs for the APC. The Hoskins Mound Unit of
Brazoria National Wildlife Refuge, acquired in February 1991,
also contains prairie habitat occupied by APC as recently as
1982. Hoskins Mound has been targeted as a potential release
site for future APC reintroductions.
The Attwater Prairie Chicken National Wildlife Refuge was
transferred to the U. S. Fish and Wildlife Service from the
World Wildlife Fund-U.S. in 1972. Recent land acquisition has
increased the size of the refuge to 7,934 acres (Fig. 3).
Management programs have included burning, mowing, herbicide
treatments, controlled grazing, food plots maintenance, and
construction and maintenance of drainage ditches. The 1992
population estimate for this refuge was 50 APC.
The 7,000-acre Tatton Unit of Aransas National Wildlife
Refuge, donated to U. S. Fish and Wildlife Service by Mr. and
Mrs. J. N. Tatton in 1967, contains approximately 2,000 acres
of marginal quality coastal prairie habitat. Much of this
area was farmed and is poorly drained. Brush encroachment by
baccharis (Baccharis halimifolia) is a major problem. Current
management programs consist of prescribed burning and grazing
deferral. Two chickens used the area in 1991, but none were
seen in 1992.
The overriding objective of management is to maintain or
improve native prairie grasslands required for APC survival.
Active management is used to create favorable habitat. APC
avoid ungrazed coastal prairie because vegetation becomes too
dense (Lehmann 1941, Kessler and Dodd 1978). Moderate grazing
removes excess vegetation and maintains winter and nesting
cover. Fall—early spring burns or mowing stimulates forb
growth, providing a winter food source and open areas for
booming grounds (Kessler and Dodd 1978). Summer mowing has
been used to remove dense vegetation and control excessive
forb growth. Herbicides and prescribed fire are used to
control invading brush species. Planting food plots provides
winter foods and habitat heterogeneity which historically
proved beneficial to APC (Lehmann and Mauermann 1963).
Ditching reduces flooding that can be a problem during nesting
and brood—rearing (Lehmann and Mauermann 1963).
13
iHlO IH1O
Headquarters *
Coushatta
Creek -
Fencelines
Roads
Marsh
FM 3013
I~I
Ffr~re 3. Attwater Prairie Chick National Wildlife Refuge.
)
0
I-
1
+
Miles
2
•1
N
I
)
TransDlants and CaDtive ProDapation
:
APC were transplanted from 2 areas where their habitat was
appropriated for other uses. Several were relocated in 2
transplant efforts from Ellington Air Force Base in Harris
County, Texas. Seventy chickens were moved in 1967 and 44 in
1970 (McCune 1970). Sixty-one of these birds were released in
Refugio and Goliad counties, and 53 were taken to Texas A&M
University to establish a captive rearing program (Lehmann
1971). This propagation attempt proved unsuccessful due to
poultry diseases and improper rearing facilities (Watkins
1971).
In 1979, 34 birds were transplanted from Gulf Airport in
Galveston County to the 6,000—acre Gonzales Ranch in Victoria
County. The transplant was unsuccessful. Of 25 radio-tagged
birds, 14 were found dead, 6 lost transmitters, and 5 could
not be located at the end of the 12-month study. No nesting
or booming activity was observed, and movements of most birds
were erratic. The birds ranged over 40,000 acres. No sex—
specific differences were noted in movement or size of areas
used. The last known prairie chicken on the release site was
a female which lost her transmitter 255 days after release.
Several factors appeared to contribute to the failure of
this transplant attempt. First, only adults were available
for transplanting. Second, drought followed the transplant
and much of the prairie habitat became overgrazed. Third, the
population in Victoria County had declined for several years.
Release habitat may have been lacking some critical component
necessary for APC survival. Fourth, a fall release may have
been inappropriate.
Efforts are currently underway to develop captive
propagation and reintroduction methods for APC using greater
prairie chickens as surrogate research birds. Fossil Rim
Wildlife Center near Glen Rose, Texas, received 15 wildtrapped
greater prairie chickens from Kansas in spring 1991
for the purpose of developing captive propagation techniques.
Twelve birds survived shipment and initial handling, and
booming behavior was observed in spring 1992. Fertile eggs
were produced but due to problems with incubators, only one
chick survived. Fossil Rim was able also to obtain 19 greater
prairie chicken eggs from a breeder in Minnesota in 1991.
Seventeen hatched successfully, and 5 survived until the next
spring.
By spring 1992 Fossil Rim was deemed ready to receive APC
eggs (49) taken from wild populations in Colorado (1 nest of
15
18 eggs) and Galveston (3 nests totalling 31 eggs) counties.
Eggs were collected in March and early April to maximize the
probability for successful renesting by the wild hens from
which the eggs were taken. Forty-three of the 49 eggs were
fertile, 42 hatched, but by the end of August 1992, only 7
survived. All chicks (17) from the Colorado County (refuge)
nest exhibited leg and foot deformities, commonly referred to
as “spraddled-legs” (legs which will not bend at the knee, but
are held out stiffly, interfering with normal walking) and
“curly toes” (toes which are constantly curled under). A
variety of techniques were attempted to correct these
deformities, but none were successful. By late August only
one refuge chick survived. These deformities may be
attributed to one of three possible causes: (1) temperature
and/or other anomalies during transport or incubation, (2) a
vitamin deficiency in the hen prior to laying, specifically of
the B—complex vitamins, and/or (3) a genetic anomaly due to
inbreeding. Plans for 1993 are to recover a total of 50—70
eggs from Refugio, Galveston, and Colorado counties. This
collection will optimize genetic diversity in the captive
flock.
Texas A&M University received 10 wild-trapped greater
prairie chickens from Kansas in spring 1991 for the purpose of
developing reintroduction techniques. Problems with stress
induced by disturbance at the pens, possible disease,
predation, and unusually heavy rainfall resulted in the death
of all birds. Two males and a brood of 16 greater prairie
chicken and sharp—tailed grouse poults < 1 week old were
obtained from a Minnesota breeder. Efforts to maintain these
birds were also unsuccessful. Texas A&M University continued
its work with greater prairie chicken surrogates in the spring
of 1992, when Cliff Steinhauer, a Wisconsin prairie grouse
breeder with extensive experience visited Texas A&M, at Dr.
Nova Silvy’s invitation. Mr. Steinhauer offered many helpful
suggestions, and with expansion of facilities, provision of
shade and dust baths, and other subtle improvements, problems
uncovered during the first year’s work were resolved.
Several research projects aimed at determining habitat
requirements and management techniques have been undertaken
since 1968. TPWD conducted a series of studies from 1968-77,
examining ranges, activities, vegetative requirements, and
population numbers (Brown 1968, Brownlee 1971—74, 1973—74,
1974, 1977, Jurries 1979). Jurries (1979) investigated
differences between habitat use and APC movement in native
prairie and ricebelt regions of Texas. In general, ricebelt
booming grounds were less stable than those in the native
16
prairie region. Brood movements appeared to be related to
food supply, with broods in the native prairie region moving
greater distances than those in the ricebelt. Brown (1981)
described the use of the helmet to capture prairie chickens.
Current work consists of censuses at yearly intervals.
The Patuxent Wildlife Research Center Field Station at
Victoria, Texas, examined a few chickens from the Attwater
Prairie Chicken National Wildlife Refuge for pesticide
residues. The chickens had trace levels (usually under 1 ppm)
of DDE (U.S. Fish and Wildlife Service 1979) which were
unlikely to present health problems.
Effects of agricultural and range management practices on
prairie chicken habitat have been examined by the Range
Science Department at Texas A&M University. Chainrad (1971)
and Chamrad and Dodd (1972) studied the effects of prescribed
burns and grazing management on APC habitat. Kessler (1978)
and Kessler and Dodd (1978) examined the response of coastal
prairie vegetation to fall and winter prescribed burns and
mowing treatments.
Dodd et al. (1975) determined the proper application rate
of the herbicide 2,4—D to diminish forbs and increase grass
herbage production and reported on APC use of fallow rice
fields. Prairie chicken use appeared to be a function of the
herbicide’s ability to accelerate plant succession, thereby
providing more cover.
The Department of Wildlife and Fisheries Sciences at Texas
A&M University initiated a series of research projects in 1975
on the ecology of the APC in Refugio County, Texas. Cogar et
al. (1977) and Horkel (1979) examined vegetative preferences
and cover requirements. They recognized 8 cover types on
their study area, and utilizing radio-telemetry techniques,
they noted that 90% of all APC locations were in the clumped
iniagrass vegetative type. The clumped inidgrass vegetative
type was dominated by tall dropseed (Sporobolus ~p~r), little
bluestem, suinpweed (L~ fn~r~n~), broomweed (Xanthoceohaluin
~ ragweed, Indiangrass, and big bluestem.
Lutz (1979) studied the effects of petroleum development
on the APC and found no major detrimental effects. Horkel et
al. (1978) reported on factors affecting success of APC nests
and dummy nests. Dummy nesting success appeared to be
influenced by the density of the nests, distance of the nests
from development, and date of initiation. Cogar (1980)
described food habits and noted that adults fed mostly on forb
foliage and seeds.
17
Lawrence (1982) found APC nests were more successful in
areas where small mammalian predators had been removed (82%
su~‘cess)than in areas of no predator control (33% success).
However, adult hens had greater mortality (63%) in areas of
predator control than did hens (41%) in areas where predators
had not been removed. Reasons for this differential mortality
could not be determined, but the possibility of an indirect
effect from predator reduction should be considered.
Morrow (1986) studied APC ecology in relation to habitat
management practices used on the Attwater Prairie Chicken
National Wildlife Refuge. He recommended that management be
focused on providing clumps of native grass species in the
2.5—din range as nesting cover. Morrow (1986) observed a shift
in habitats preferred by broods as the brooding period
progressed. Early in the period, broods used grasslands
stands similar to those used for nesting. Beginning in midJune,
broods used much more open habitats such as those found
on first—year burns and coarse sand range sites. Morrow
(1986) recommended that habitats satisfying all brood
requirements be well interspersed with nesting habitat in
order to reduce brood movements.
Private Land Initiatives
:
• Increases in chicken numbers without acquisition of
additional public lands must result from: (1) improved
management on existing public lands and/or (2) new management
efforts on private lands. Control of brush and increased
extension efforts to reduce overgrazing on private lands
represent the greatest potential for increasing APC numbers
rangewide. Recently, increased efforts have been made to
provide technical assistance and economic incentives to
landowners for providing improved range conditions for APC’s.
Agreements have been signed between the Service and large land
holders to provide technical assistance on APC management.
TPWD has also obtained grazing rights to approximately 4,600
acres of APC habitat in Victoria and Austin counties in
exchange for monetary payments or brush control work. Monies
for these projects have been provided to TPWD on a 75:25
matching basis by the Service as authorized by Section 6 of
the Endangered Species Act. From 1990 to 1992, TPWD committed
approximately $40,000/yr for APC habitat restoration on
private lands.
G. STRATEGY OF RECOVERY
Recovery will be organized around 5 major thrusts:
18
(1) Maintain and restore high quality coastal prairie
grasslands. This effort will include acquisition of
a second refuge with high-quality APC habitat which is
geographically separated from APCNWR. Also included
in this effort are habitat enhancements on existing
public lands, and providing assistance and incentives
to private landowners to maintain prairie grasslands.
(2) Raise the public’s awareness of the APC and its
endangered prairie ecosystem.
(3) Encourage and coordinate legislative and regulatory
programs that provide incentives to private landowners
who maintain endangered species habitat. Examples
include providing information to landowners about
programs that provide economic incentives such as tax
breaks or monetary payments for endangered species
management (Fritz 1985, Internal Revenue Service
Regulations 1991, State of Texas 1991). An important
part of this strategy includes assisting landowners in
solving problems associated with endangered species
management.
(4) Develop and implement captive propagation and
reintroduce into suitable habitats.
(5) Conduct management—oriented research designed to
identify limiting factors and develop procedures for
their removal.
II. RECOVERY
A. OBJECTIVES AND CRITERIA
OBJECTIVE: To ensure the survival of the Attwater’s
prairie chicken and to remove it from the endangered
and threatened species list using the following
criteria:
1. Downlist to threatened status when the population
reaches 3,000 birds. These birds should be split
between 2 or more geographically separated
populations.
2. Delist when there is a minimum population of
5,000 birds and approximately 30,000 acres of
suitable habitat are being managed for APC
restoration.
19
B. NARRATIVE OUTLINE FOR RECOVERY ACTIONS ADDRESSING
THREATS
1. Protect and manage habitat
.
Unquestionably, habitat is LI3~ major factor
currently limiting ARC populations. The ARC’s
prairie grassland habitat has been reduced by an
estimated 97% of historic levels. Remaining
habitat is fragmented, making isolated APC
populations more susceptible to localized weather
extremes, land use changes, predation, and
disease. Strategies for habitat protection and
enhancement will require acquisition and
management of 2 (15,000 acres each) areas. These
two land units will be core ARC habitats.
Private lands initiatives will be used to develop
nesting habitat within an ecologically-patterned
system of smaller satellite grassland habitats
radiating from the two core areas.
Lands with 15% permanent grassland cover have
supported approximately 10 greater prairie
chickens/mi2 (Hamerstrom et al. 1957). Assuming
statewide APC populations will return to 1,000
birds on existing habitat after recovering from
the 1987—90 drought, an additional 40,000 acres
of nesting habitat will be needed to attain the
5,000-bird level required for delisting. Private
lands initiatives offer the best opportunity to
provide this habitat without public acquisition.
11. Public land management
.
111. Manaae refuges
.
Manage existing national wildlife
refuges to maintain, improve, and/or
restore native prairie grasslands as
APC habitat.
1111. Manaae grazing
.
Manage grazing to maintain
good—excellent range condition
(>50 percent climax grass
species).
20
1112. Implement burning
.
Implement prescribed burning
program while adhering to
appropriate Texas Air Control
Board regulations.
1113. Control brush
.
Control invading brush species.
1114. Maintain/improve drainage
.
Reduce nest flooding.
1115. Maintain food Dlots
.
Provide supplemental winter
foods.
1116. ImDleinent mowing
.
Implement mowing as necessary
to control vegetation density.
1117. Manaae problem wildlife
species
.
11171. Implement predator
control
.
Implement predator
control/management as
necessary.
11172. Control exotic birds
.
Control exotic game
birds, including ringnecked
pheasants.
11173. Control fire ants
.
Control/manage imported
fire ants (~ljfl~~g.J.~
spp.) as necessary,
after conducting
research to determine
(1) if fire ants are a
major limiting factor
for ARC populations
and, (2) if so, what
the most effective
methods are to minimize
their impacts.
21
11174. Manage waterfowl
.
Manage waterfowl,
especially geese, to
minimize competition
and potential for
disease transmission.
1118. Restore prairie
.
Restore formerly farmed fields
to native prairie species.
1119. Control public use
.
112. Acquire lands
.
Acquire additional public lands from
willing sellers for ARC management.
1121. Acquire second refucre
.
Acquire a second,
geographically separated refuge
of 15,000 acres through a
combination of fee simple and
long—term easement
acquisitions.
1122. Add to existing refuge
.
Add an additional 7,000 acres
to the existing 8,000—acre
APCNWR through a combination of
fee simple and long-term
easement acquisitions.
113. Survey bird numbers annually
.
1131. Survey spring leks (booming
gx~n~
Use helicopters, and biologists
on foot (where practical) to
annually survey all known
display areas.
1132. Survey brood survival
Use helicopters and rope
dragging to annually survey
selected sites for brood
survival in late June and early
July.
22
12. Private lands assistance
.
121. Provide technical assistance
.
Provide technical assistance with ARC
and native prairie management. Use
expertise from government and private
sources such as the Service, TPWD,
Texas Agricultural Extension Service,
U.S. Soil Conservation Service, and
the Gulf Coastal Prairies Foundation.
122. Provide economic incentives
.
Provide economic incentives for
improved range management.
13. Protect essential habitat
.
Protect essential habitat Figs. 4, 5, 6,
and 7) and counties with extant prairie
chicken populations.
Essential habitat in this document is a
planning term used to describe areas of
current or former prairie which are
considered important for recovery of ARC.
Essential habitat includes areas which are
not occupied by APC. Inclusion of such
areas not currently inhabited does not mean
they should be subject to increased
regulation or that they are targeted for
acquisition. Areas indicated as wooded on
USGS topographic maps are excluded from
essential habitat.
Essential habitat should not be confused
with critical habitat as defined by the
Endangered Species Act. Critical habitat
has not been designated for the APC.
131. ImDlement ESA
.
Implement appropriate provisions of
the Endangered Species Act.
132. Use EPA Authority
.
Use Environmental Protection Agency
authority regarding use of pesticides
and hazardous chemicals.
133. Use State authority
.
23
) ))
N
0 10 20
MILES
ESSENTIAL HABITAT
Figure 5. Essential habitat in Galveston County, Texas.
0 10 20
ESSENTIAL APC HABITAT
MILES
ARANSAS NWR
LII
Flaure 6. Essential habitat in Goliad, Refugio, and Aransas counties, Texas.
) )
) ))
Miles
I I
Liii ESSENTIAL HABITAT
Figure 7. Essential habitat in Victoria County, Texas.
134. Use ASCS authority
.
Use U.S. Agricultural Stabilization
and Conservation Service authority.
14. Protect sDecies
.
Protect species from take.
141. Enforce laws
.
Enforce current legislation and
regulations.
1411. Federal
.
1422. State
.
2. Public education
.
Increase public outreach to raise the public’s
awareness of the plight of the APC and their
endangered ecosystem. A lack of understanding
currently exists among the general public
concerning the perilous condition of ARC
populations. This lack of awareness has
resulted in generally low levels of public
support for ARC recovery programs. Increased
extension efforts are needed to provide land
managers with information on native prairie
management.
21. Enhance media coveracre of poDulation
status
.
Enhance media coverage of issues related to
the APC’s population status.
22. Encourage media coveraae of recoverv
efforts
.
Encourage media coverage of ongoing
recovery efforts.
23. Enhance Dublic use
.
Enhance public use facilities and staff on
the APCNWR.
24. Increase educational activities
Increase educational activities with school
groups and environmental organizations.
28
25. Continue newsletter
.
Continue publication of the “Attwater’s
Prairie—Chicken Status Report” or a similar
publication.
26. Continue annual APC or Gulf Coastal
Prairies symDosium
.
27. Increase extension efforts
.
Increase extension efforts with landowners.
271. Produce publications
.
Produce extension publications and a
video tape promoting sound range
management practices.
272. Utilize demonstration areas
.
Utilize existing management efforts as
demonstration areas.
28. Prevent shooting loss
.
281. Increase hunter awareness
.
282. Prepare media announcements
.
283. Educate hunters
.
Educate hunters in areas of pheasant
introductions.
3. Encourage landowner incentives
.
Encourage and coordinate legislative and
regulatory programs which provide incentives to
landowners who maintain ARC habitat.
31. Inform landowners
.
Provide information about the availability
of such programs to landowners.
32. Encouracre feedback from landowners
.
Gather information on any hardships to
landowners caused by implementation of
legislative and regulatory programs.
4. linDlement caDtive oropagation and
reintroduction
.
Implement captive propagation and reintroduction
into suitable habitats within the historic
29
range. Acceptable techniques should be
developed using greater prairie chickens as
surrogates before ARC are taken into captivity.
41. DeveloD two DroDacjation facilities
.
Implement APC captive propagation programs
in at least two locations following Service
policies.
42. Identify release sites
.
Develop and implement a reintroduction
program which includes identifying sites
which maximize the probability for success.
43. Prevent introduction of other grouse
.
Prevent establishment of other grouse
species within the ARC historic range.
5. Research management techniques
.
Although considerable research has been
conducted on the ARC, most studies focused on
general ecology and habitat use. Much remains
unknown regarding potential limiting factors and
their interaction. Specific information gaps
include the relative importance of predation,
disease, and genetic anomalies, particularly in
small populations, as ARC limiting factors.
Information is also needed on the distribution
and availability of habitat rangewide to
facilitate site selection for potential
reintroduction sites.
51. Identify limiting factors
.
Identify limiting factors and solutions for
removing them.
511. Rangewide habitat assessment
.
512. Mortality factors
.
5121. Disease
.
5122. Br~~X±Qn.
30
513. Demography and genetics
.
5131. Assess Dopulation dynamics
.
Assess reproduction and
mortality in the context of the
APC’s life history.
5132. Assess genetic variability
.
Assess and document genetic
variability within remaining
ARC populations.
5133. Identify thresholds
.
Identify thresholds for
population intervention
52. Develot propagation and reintroduction
techniaues
.
Conduct research necessary to implement
captive propagation and reintroduction
programs. Such activities should include
gathering information on behavior,
physiology, disease, and genetics.
31
C. LITERATURE CITED
Bendire, C. B. 1894. Tympanuchus americanus attwateri
Bendire. Attwater’s or southern prairie hen. Auk 11:130—
132.
Brown, D. L. 1968. Prairie chicken range appraisal. Texas
Parks and Wildl. Dept. Job Prog. Rept., W-92-R-4. 12 pp.
_________ 1981. The helmet: A device for capturing
prairie chickens and ring—necked pheasants. Proc. Ann.
Conf. Southeastern Assoc. Fish and Wildl. Agencies 35:92-
96.
Brownlee, W. C. 1971-74. Seasonal territorial ranges of
Attwater’s prairie chicken. Texas Parks and Wildl. Dept.,
Job Prog. Repts., W-100—R—2, 3, 4, and 5. 13 pp.
_________• 1973-74. Activities of the prairie chicken
within its seasonal range. Texas Parks and Wildl. Dept.,
Job Prog. Rept., W-100—R—4 and 5. 2 pp.
_________• 1974. Vegetative requirements of the Attwater’ s
prairie chicken. Texas Parks and Wildl. Dept., Job Prog.
Rept., W-l00-R-5. 2 pp.
_________ 1977. Attwater’s prairie chicken population
census. Texas Parks and Wildl. Dept., Job Prog. Rept., W—
l00—R—5. 2 pp.
Chamrad, A. D. 1971. Effects of fire and grazing on coastal
prairie rangeland and Attwater’s prairie chicken habitat.
Ph.D. Thesis, Texas A&M Univ., College Station. 120 pp.
, and J. D. Dodd. 1972. Prescribed burning and
grazing for prairie chicken habitat manipulation in the
Texas coastal prairie. Proc. Tall Timbers Fire Ecol.
Conf. 12:257—276.
Cogar, V. F., J. D. Horkel, and N. J. Silvy. 1977.
Vegetation type preference of Attwater’s prairie chicken
in coastal prairie. Proc. Southeastern Assoc. Fish and
Wildl. Agencies 31:41—50.
_________• 1980. Food habits of Attwater’s prairie chicken
in Refugio County, Texas. Ph.D. Thesis. Texas A&M Univ.
College Station. 119 pp.
32
Dodd, J. D., R. Jurries, and A. T. Weichert. 1975.
Stimulating native forage production for livestock and
wildlife on fallow riceland. Progress Rept., Texas Agri.
Exp. Stn. 8 pp.
Fritz, E.C. 1985. Another way to save nature: conservation
easements. Texas Land Use J. (summer) pp. 4—5
Hamerstrom, F.N., Jr., O.E. Mattson, and F. Hamerstrom. 1957.
A guide to prairie chicken management. Wisconsin Consery.
Dept. Tech Wildl. Bull. 15. 128 pp.
Horkel, J. D. 1979. Cover and space requirements for
Attwater’s prairie chicken (I uPkn~J1~ Q3~i~ attwateri
)
in Refugio County, Texas. Ph.D. Thesis, Texas A&M Univ.,
College Station. 96pp.
, R. S. Lutz, and N. J. Silvy. 1978. The
influence of environmental parameters on nesting success
of upland game birds. Proc. Southeastern Assoc. Fish and
Wildl. Agencies. 32:234—241.
_________ and N. J. Silvy. 1980. Evolutionary
considerations in creating artificial leks for Attwater’s
prairie chicken. Pages 42—47 in P. A. Vohs, Jr. and F. L.
Knopf, eds. Proc. Prairie Grouse Symp. Oklahoma State
Univ., Stillwater.
Internal Revenue Service. 1991. Internal Revenue Service
regulations. Section 1.170 A-l:763—768.
Jennings, W. 5. 1950. Abundance distribution and present
status of Attwater’s prairie chicken. Final Rept. to the
Texas Coop. Wildl. Unit., Texas A&M Univ. College
Station. 37pp. (mimeogr.)
Jones, R. E. 1963. Identification and analysis of lesser and
greater prairie chicken habitat. J. Wildl. Manage.
27:757—777.
Jurries, R. W. 1979. Attwater’s prairie chicken. Texas
Parks and Wildl. Dept. Series F. A., No. 18. P—R Project
W-lOO-R. 36pp.
Kessler, W. B. 1978. Attwater’s prairie chicken ecology in
relation to agricultural and range management practices.
Ph.D. Thesis, Texas A&M Univ., College Station. 158pp.
33
, and J. D. Dodd. 1978. Responses of coastal
prairie vegetation and Attwater’s prairie chicken to range
management practices. Proc. Int. Rangeland
Congr. 1:473—476.
Lawrence, J. 5. 1982. Effect of predator reduction on the
reproductive success of Attwater’s prairie chicken. M.S.
Thesis, Texas A&M Univ. College Station. lO5pp.
, and N. J. Silvy. 1980. Status of the Attwater’s
prairie chicken——an update. Proc. Prairie Grouse Symp.
1:29—33.
Lehmann, V. N. 1941. Attwater’s prairie chicken, its life
history and management. U. S. Dept. Interior, Fish and
Wildl. Serv., Washington, D.C. N. Am. Fauna 57. 63 pp.
_________ 1968. The Attwater’s prairie chicken, current
status and restoration opportunities. Trans. N. Am.
Wildl. Conf. 33:398—407.
_________ 1971. Attwater’s prairie chicken. Natl. Parks
and Conserv. Mag. 45:1—4.
, and R. G. Mauermann. 1963. Status of Attwater’s
prairie chicken. J. Wildl. Manage. 27:713—725.
Lutz, R. 5. 1979. The response of Attwater’s prairie chicken
to petroleum development. M.S. Thesis, Texas A&M Univ.,
College Station. 82 pp.
McCune, R. A. 1970. Prairie chicken moving days. Texas
Parks and Wildl. Nag. 18:12-15.
Morrow, N. E. 1986. Ecology of Attwater’s prairie chicken in
relation to land management practices on the Attwater
Prairie Chicken National Wildlife Refuge. Ph.D. Thesis,
Texas A&N Univ., College Station. 100 pp.
Robel, R. J. 1970. Possible role of behavior in regulating
greater prairie chicken populations. J. Wildl. Manage.
4: 306—312.
_________ J. N. Briggs, A. D. Dayton, and L. C. Hulbert.
1970. Relationships between visual obstruction
measurements and weight of grassland vegetation. J. Range
Manage. 34:286—306.
State of Texas. 1991. Conservation easements. Texas Nat.
Resour. Code, Chap. 183:163—166.
34
U.S. Fish and Wildlife Service. 1979. Attwater’s prairie
chickens have low pesticide residues. Pages 34—35 in T.
G. Scott et al., eds. Fisheries and Wildlife Research,
1978.
__________ 1983. Attwater’s prairie chicken recovery plan.
U.S. Fish Wildl. Serv., Albuquerque, NM. 48 pp.
Watkins, R. N. 1971. The propagation of the Attwater prairie
chicken in captivity. N.S. Thesis, Texas A&M Univ.,
College Station. 38 pp.
Westemeier, R. L. 1986. Endangered prairie—chickens and some
species interactions. Illinois Nat. Hist. Surv. Rep. No.
286:1—2.
35
III. IMPLEMENTATION SCHEDULE
The implementation schedule outlines actions and
estimated costs for recovery. It is a guide for meeting the
objectives discussed in Part II of this plan. This schedule
indicates task priority, number, description, duration,
responsible agencies, and estimated costs. These actions
should bring about the recovery of the species and protect its
habitat. Estimated monetary needs for all parties are
identified. Part III reflects the total estimated financial
requirements for recovery of this species through the year
2000.
A. Task Priority - Tasks in the Implementation Schedule are
arranged in priority order. Priorities are assigned using the
following guidelines:
Priority 1 - An action that must be taken to prevent
extinction or to prevent the species from declining
irreversibly in the foreseeable future.
Priority 2 - An action that must be taken to prevent a
significant decline in species population/habitat quality, or
some other significant negative impact short of extinction.
Priority 3 — All other actions necessary to meet the recovery
objectives.
Key to Acronyms Used in Implementation Schedule
Fossil Rim Wildlife Center (FR)
Louisiana Department of Fish and Game (LAFG)
Gulf Coastal Prairies Foundation (GCPF)
Texas Agricultural Extension Service (TAES)
Texas A&M University (TAMU)
Texas Animal Damage Control (ADC)
Texas Department of Agriculture (TDA)
Texas Parks and Wildlife Department (TPWD)
Texas Tech University (TTU)
U.S. Department of Agriculture (USDA)
U.S. Fish and Wildlife Service Endangered Species (SE)
U.S. Fish and Wildlife Service Law Enforcement (LE)
U.S. Fish and Wildlife Service Legislative Affairs (LA)
U.S. Fish and Wildlife Service Public Affairs (PA)
U.S. Fish and Wildlife Service Refuges and Wildlife (WR)
U.S. Fish and Wildlife Service Research (RSCH)
U.S. Soil Conservation Service (SCS)
36
1
)
PRIORTIY
T
TASK TASK
DF&IRIPTIc!4
TASK
DURI4TION
(yps)
RRSP(~SIB1E PARIY (flSP FgI’ThATE~ ($000)
X~4ME~ffS
RFXI()I PEGRAI4 OThER FY93 FY94 FY95
1 1111 Manage grazing ongoing 2 WR TPWD,
SCS
50 50 50 Public
lands only
1 1112 lmp1e~nt burning ongoing 2 WR TPWD,
SCS
100 100 150 4 refuges,
20K acres
1 1113 Control brush ongoing 2 WR TPWD,
SCS
100 100 50 Public
lands only
1 1114 Maintain/improve
drainage
ongoing 2 WR WWD,
SCS
5 5 5 Public
lands only
1 1121 Acquire second refuge 3 years 2 WR 6,000 8 8 Victoria
County
1 1122 Add to existing
refuge
3 years 2 WR 5,000 5,000 5,000 Austin and
Colorado
counties
1 121 Use available
expertise
ongoing 2 WR, SE TPWD,
SCS
500 500 500 Historic
range
1 122 Provide econcinic
incentives
ongoing 2 WR,SE TPWD,
GCPF
330 330 330 Private
lands
1 21 F~ihance media coverage
of population status
ongoing 2 IVR,PA TPWD 10 10 10
1 22 Ekicourage media
coverage of recovery
efforts
ongoing 2 WR,PA TPWD 10 10 10
1118 Restore prairie ongoing 2 IYR TPWD,
scs
100 100 100 Public
lands only
(J.,
—4
PRIORITY TASK
t
TASK
DESCRIFFIa’!
TASK
DURATIa’~
(YRS)
RESK~4SIBIE PARIY CflST F~TIMATF~ ($000)
~X~iMEN~S
FWS
(JflI~ FY93 FY94 FY95RFXII(1’! PROGRAM
1 23 F~ibance public use ongoing 2 WR 150 8,150 8,150 Staff 2
visitor
sites
1 24 Increase educational
activities
ongoing 2 WR TNT) 50 50 50
1 25 Continue newsletter ongoing 2 WR GCPF 8 8 8 Quarterly
publication
1 26 ContinueApCSympoeiizn ongoing 2 WR GCPF 10 10 10
1 271 Produce publications ongoing 2 WR,PA TAES,
GCPF
100 100 100
1 272 Utilize da~nstration
areas
ongoing 2 IVR,PA TPWD 20 20 20
1 31 Inform landowners ongoing 2,4 PA GCPF 50 50 50 E’tension
1 32 Encourage feedback frcin
landowners
ongoing 9 LA OCPF 25 25 25 Prcmte
landowner
incentives
for SE
1 41 Develop two propagation
facilities
ongoing 2 WR TAMU,
FR
120 120 120
1 42 Identify release sites ongoing 2 WR TAMU,
FR
120 120 120
1 43 Prevent introduction of
other grouse
ongoing 2 WR,LE TPWD 5 5 5 Education
)
IA
PRIORITY
T
TASK
*
TASK
DESCRI1’PIa4
TASK
DURATION
(yp5)
RESRMSIBLE PARIY (fl~I’ ESTIMATES ($000)
r~i~wrs
FMS
OIlIER FY93 FY94 FY95RF)31ON PROGRAM
1 511 Rangewide habitat
assessment
ongoing 2,8 WR,SE TANU 60 60 60 Texas and
Louisiana
1 5121 Disease research onqoinq 2
2,8
WR,SE TANU 60 60 60
1 5122 Predation research ongoing WR,SE rm 60 60 60
1 5131 Assess population
dynamics
ongoing 2,8 IVR,SE TNIU 150 150 150
1 5132 Assess genetic
variability
ongoing 2,8 WR,SE TANU, 60 60 60
1 5133 Identify thresholds ongoing 2,8 WR,SE TAMU, 10 10 10
1 52 Develop propagation and
reintroduction
techniques
ongoing 2,8 WR,SE TAMU,
FR
50 50 50 Research
2 1116 Implenent oDwing ongoing 2 WR TNT),
SCS
20 20 20 Public
lands only
2 11171 Impl~nent predator
control
ongoing 2 WR TNT),
ADC
50 50 50 4 refuges,
50K acres
2 11172 Control exotic birds ongoing 2 IVR,SE TNT) 50 50 50 Within 40J~n
of existing
populations
2 11173 Control fire ants ongoing 2 WR USDA,
ThA
100 100 100 Research &
managsi~nt
2 11174 Manage waterfowl ongoing 2 WR TPWD 50 50 50 Avian
cholera
IA
PRIORITY TASK TASK
DESCRIFVION
TASK
DURATION
(YRS)
RESKWSIBLE PARIY (1fl6’P F~PTh1ATES ($000)
Q]~4~J~Tp5
RFGION PROGRAM OIlIER FY93 FY94 FY95
2 131 Implenent ESA ongoing 2 WR,LE TNT) 10 10 10
2 132 Use EPA authority ongoing 2 SE TT)A 20 20 20
2 133 Use State authority ongoing 2 WR TNT) 20 20 20
2 134 Use ABCS authority ongoing 2 SE ABCS 20 20 20
2 1411 Enforce Federal laws ongoing 2 WR,LE TNT) 10 10 10
2 1422 Enforce State laws ongoing 2 LE TPWD 10 10 10
2 281 Increase hunter
awareness
ongoing 2 WR,PA,LE TNT) 5 5 5 Minimal
threat
2 282 Prepare media
announc~nents
ongoing 2 WR,PA TNT) 2 2 2 Spring and
Fall
2 283 Educate hunters ongoing 2 WR,PA TNT) 5 5 5 Minimal
threat
3 1115 Maintain food plots ongoing 2 WR TND,
SCS
10 10 10 Public
lands only
3 1119 Control public use ongoing 2 WR,PA 100 100 100 4 refuges
) )
0
IV. APPENDIX I. COMMENTS
A. PRINCIPAL COMMENTS RECEIVED ON THE ATTWATER’S PRAIRIE
CHICKEN TECHNICAL/AGENCY DRAFT RECOVERY PLAN
Twenty—eight individuals or agencies requested copies of
the plan for review. Five responses were received, each
containing relevant and helpful remarks. All comments were
considered when revising the draft. The authors appreciate
the time contributed by each reviewer. Comments discussed
below represent a composite of those received. Comments of
similar content are combined into general groups. Only
critical comments, those raising a question, or suggestions
are included in this discussion. Comments were received from
the following individuals:
Sidney A. Gauthreaux, Jr.
Department of Biological Sciences
Clemson University
Clemson, SC 29634—1903
Brandt Mannchen
Wildlife Committee
Lone Star Chapter of the Sierra Club
627 Euclid
Houston, TX 77009
Michael B. Muse
Rt. 1, Box 363-F
Byhalia, MS 38611
Rob R. Reid
Espey, Huston & Associates, Inc.
P.O. Box 519
Austin, TX 78767
Dennis Williams
2804 Loma Vista
Victoria, TX 77901
~~nrn~nLi. The plan implies that captive breeding is not a
viable option. There are several experienced grouse breeders
in the United States who would do a great job of breeding the
ARC and provide more birds for release. The Service should
strongly consider a “Breeder Loan” or “Sharing Agreement” with
a few carefully selected individuals who have been successful
raising greater prairie chickens, and provide funding to
support this effort.
41
Service ResDonse. Captive breeding is a priority issue. ARC
are successfully being raised in captivity at a private
wildlife center in Texas. Texas A&M University is also
working with surrogate greater prairie chickens (GPO) to
deyelop techniques for future ARC reintroductions. The
Service is also communicating with both the Fort Worth and
Houston Zoos regarding captive propagation.
Comment 2. The re-mapping of “essential habitat”, and its
revised definition, is inappropriate and will cause confusion
and possible abuse of the term. The essential habitat as
mapped contains not only high—quality habitat, but also
marginal habitat and large areas of non-prairie habitat (e.g.,
woodlands, farmland with crops, petrochemical facilities,
large areas with varying degrees of encroachinent by woody
vegetation). Habitats should be classified as they exist at
present, or at the very least delimited as “former prairie”
and “current prairie” to indicate what is currently suitable
habitat for ARC. Other possible designations are “historic
habitat” and “good/high-quality habitat.” Truly high-quality
habitat should be designated as “critical habitat.” Mapping
should also show areas currently occupied by ARC.
Service Response. “Essential” habitat is all potential
habitat necessary to recover the ARC (i.e. provide for 5,000
birds in the wild). Critical habitat has a specific
designation under the Endangered Species Act and may be
designated in the near future.
Comment 3. A public education program should be developed
immediately to inform the public that the APC is near
extinction and to gain their support for saving this species.
The program should identify the need for another refuge and
ways private landowners can help with recovery.
Service Restonse. We agree. A private foundation is
presently implementing such a program. The refuge is also
pursuing a public outreach program with limited resources (no
Outdoor Recreation Planner). Coordination with other agencies
and organizations is desirable.
Comment 4. More emphasis should be placed on public
acquisition of additional lands by willing seller, willing
buyer, fee purchase or conservation easements. Areas not
prone to flooding should be acquired near APC habitat prone to
flooding to provide an escape area. A specific plan should be
drawn up that shows where possible refuge sites are; the
positive and negative aspects of each site; and habitat
connecting public, proposed public, and private ARC habitat.
This plan should include some form of long—term land use
42
-~ protection (such as “in perpetuity”) to ensure that farming
and ranching compatible with recovery is guaranteed in a
buffer zone around the core private and public refuges.
Commitments should be sought from interested groups and
individuals for passage of land protection legislation.
Programs should also be utilized under which private
landowners agree to use farming and ranching methods that
protect the APC in return for monetary support from the
government.
Service ResDonse. USFWS has identified a second refuge site
in Victoria County where topography and soils are good and a
willing seller exists. Private lands efforts include
memoranda of understanding with landowners and Section 6
leases between private landowners and the TPWD. All these
efforts are coordinated to provide contiguous habitat for the
birds where they persist.
Comment 5. Acquisition by TPWD of the Texas City site in
Galveston County should be encouraged, and a buffer purchased
to ensure protection from land uses outside this area.
Service Response. We agree. USFWS and TPWD are working
cooperatively to recover the APC, as well as other projects.
Comment 6. The objectives for downlisting and delisting the
species are too optimistic. For threatened, the population
level should be 5,000 in at least 3 separate populations in 3
geographic areas. For delisting, the population level should
be 10,000 in 5 separate populations in at least 3 geographic
areas.
Service Response. The USFWS accepts the recommendation of the
Recovery Team and other experts on APC management
(3,000/5,000/2 areas).
Comment 7. The statement made about the Tatton Unit is
incorrect. The Tatton Unit was not managed correctly for APC;
private landowners should not be blamed.
Service Response. We agree. Statements made about the Tatton
Unit have been modified to reflect past management practices.
Comment 8. The assertion that linear leks are less stable
than circular leks needs further evaluation. There are few
natural circular leks still in use, and if linear leks are so
bad, why do we (Refugio County) have all the birds?
43
Service Response. At least 2 independent research projects
have indicated specific problems associated with linear leks.
However, size and quality of habitat are more important than
lek structure.
Comment 9. If moderate grazing removes excess vegetation,
etc., why are there no cattle at the Tatton unit?
Service ResDonse. Abusive grazing practices in the past have
eliminated many desirable grasses. Use of cattle as a
management tool will be considered after these grasses have
been restored.
Comment 10. Too much emphasis is put on burning as a brush
management method. There have been no major burns, either
planned or wild, in the Refugio County area in the last 35 or
40 years. Old ranch records do not reference any planned
burns on land now occupied by the APO in Refugio County.
Service Response. The literature supports the use of burning
as a management tool; however — alternative methods of brush
control such as use of chemicals, combined with proper grazing
management may reduce the need for an intensive burning
program.
~gmm~nLUL. Have wetlands rules been considered in plans to
maintain/improve drainage?
Service Response. All drainage maintenance/improvement will
comply with pertinent policies and regulations.
Comment 12. What conclusive evidence is there that
maintaining food plots benefits the Attwater’s prairie chicken
and is not just a further disruption of native prairie?
Service Response. Although the necessity of food plots for
ARC is undocumented, use -of such areas indicates that may
provide dietary requirements that are otherwise limiting. The
USFWS shares the concern that excessive amounts of native
prairie not be destroyed in producing such food plots.
~Qm~inLia. Why not use cows instead of mowing?
Service Response. Mowing is only an emergency technique for
removing excess growth in periods of unusually high rainfall.
Grazing is the preferred tool.
Comment 14. If managing waterfowl is so important, why are
there lakes and/or ponds at the Attwater Prairie Chicken
44
National Wildlife Refuge? Consideration should given to
draining them.
Service Response. Lakes and ponds support a diverse wildlife
fauna. The refuge staff has considered the potential impacts
of geese on refuge APC, and have taken steps to reduce/prevent
such impacts.
Comment 15. To get more dollars for recovery efforts, ARC
need to be made more available to the public instead of less
accessible.
Service Response. We agree as long as appropriate actions are
taken to ensure the associated disturbance does not impede
recovery.
Comment 16. The use of EPA authority should be reconsidered.
This causes more hard feelings than it does good. Is there
any proof that pesticides are a problem?
Service Response. An agriculture/wildlife coexistence
committee for the Texas rice belt is developing guidelines for
EPA using local, grassroots input from ranchers, farmers, and
businessmen.
Comment 17. The map of essential habitat in Goliad, Refugio,
and Aransas counties should be changed to show brush
encroachment.
Service Response. We agree. GIS maps are complete for
northern Victoria, Austin, and Colorado counties. Additional
maps are being developed for remaining ranges.
Comment 18. The Victoria County map should be changed to show
only a small area between US 87 and across US 77 (both north
of US 59); the remaining area consists of brush, houses, and
farms.
Service ResDonse. We agree. Note the GIS—generated map for
northern Victoria County. Further mapping will delineate
additional prairie sites in southern Victoria County, believed
essential for recovery. The designation of prairie habitat
does not imply that birds are present now on these essential
areas.
Comment 19. Water should be made available to aid ARC during
drought.
Service ResDonse. Cattle watering systems should provide
enough water in times of drought.
45
Comment 20. The Service should help build leks with roads,
herd grounds, well pads or watering areas.
Service Response. Leks have not been identified as a limiting
factor (Horkel 1979).
Comment 21. The Service should give high priority to cleaning
up brush and building escape areas on the Tatton Unit.
Service Resnonse. We agree.
Comment 22. Breaks should be made in the underlining for the
scientific names of plants and animals between genus, species,
and subspecies.
Service Response. We agree. Recommended changes are
incorporated in document.
Comment 23. The reference to historic range by Lehinann found
on page 1 is incorrect as stated. Page 1 of the Lehiuann
(1941) document states “...and in Texas west and south to
Cameron County, near Port Isabel.” Additionally, Page 5
(second paragraph) of the draft recovery plan also states
Attwater’s prairie chickens were found south to Tamaulipas,
Mexico.
Service Response. Lehinann (1941:3) states “There are no
authentic records of the occurrence of any species of prairie
chicken in Texas south of northern Aransas County, except for
one bird reported near Brownsville...”. Lehinann (1968:398)
refers to the ARC as “...once common on Gulf coastal prairies
from southwestern Louisiana southward the Nueces River in
Texas.”
~mm~nL2~A. Based upon the census results of the last few
years, it is inappropriate to state that the very few birds,
if any, located in Goliad and Aransas counties are a part of
67% of the rangewide population. Almost all (if not all) of
the ARC occur in Refugio County. Therefore, it would be more
appropriate to state that 67% of the rangewide population
occurs in Refugio County.
Service Response. County lines do not separate wildlife
populations. Specific census data are listed by county in
which the birds occurred (Table 1).
Comment 25. The 1992 population estimates should be
incorporated.
46
Service Response. We agree. The 1992 data have been
incorporated.
Comment 26. The statement that Goliad and Refugio populations
appear to be intertwined is only a hypothesis and is not
supported by data.
Service Resnonse. The plan states it as a hypothesis and
cites reasons for this hypothesis.
Comment 27. The discussion concerning the intertwined
relationship of Goliad and Refugio populations following
hurricane Beulah in 1967 is not supported by population data.
Following the hurricane in 1967, populations increased in kQ~11
counties until 1971, decreased in kQ~ii counties until 1972,
showed slight changes in ~h counties in 1973, and then
increased in both counties in 1974. The data do not support
the statement that the Refugio County population “crashed”
following hurricane Beulah. To allude to a theory that the
birds moved back and forth between counties over a 4—7 year
period because of a hurricane is not supported and may more
likely be a response to habitat conditions and population
dynamics.
Service Response. Regarding the impacts of Hurricane Beulah
-~ on the Aransas—Refugio-Goliad prairie, Lehinann (1968:402)
states “In what historically has been the best chicken range,
however, Hurricane Beulah was followed by sharp decline—from
an estimated 1,200 to 1,500 birds in July to about 250 in late
October.” We did not “allude to a theory that birds moved
back and forth between counties...”. Rather, as suggested by
the author of this comment, we hypothesized that the birds
responded to changes in habitat condition resulting from
climatic changes.
Comment 28. The Horkel (1979) reference cited on page 6 ~
not state that APC avoid cover types consisting of NQrk~n
2.i~ trees and brush. It is clear from the Horkel reference
that APO prefer habitat with ~Q presence of brush or trees.
Page 75 (first paragraph) of the Horkel (1979) reference
states “No use was made of the selected cover types (clumped
inidgrass, spiney aster and transition) that had been invaded
by trees or brush on the pasture.” The avoidance of habitat
containing woody species is also stated in Cogar, et al.
(1977). The statement regarding the 25% brush cover should be
removed or an accurate reference provided.
Service Response: We agree. However, APC have been recorded
perching in trees (Silvy, pers. comm.), and APO in Galveston
County have been observed nesting in grasslands in early
47
stages of brush encroachment (USFWS unpubl. data). This does
not imply that trees or brush are a desirable component of APC
habitat, only that APC can tolerate minimal woody plants in
their habitat. The statement has been changed accordingly.
Comment 29. Service efforts to enter into MOUs with private
landowners are very worthwhile, but should be concentrated in
areas of high—quality habitat capable of supporting APC
populations and not in marginal habitat which may become more
degraded conditions even with landowner participation in the
program.
Service ResDonse. This has been and is being done.
Comment 30. A statement should be added stating that the term
“essential habitat” has been redefined since the 1983 recovery
plan.
Service Resoonse. We agree. Item 13 in the Narrative Outline
has been modified to clarify use of essential habitat.
Comment 31. The increase in the area mapped for Victoria
County from about 10% of the county in the 1983 recovery plan
to 75-80% of the county in the new revised plan is
inappropriate for the inclusion within the term “essential
tlabitat,u even considering the revised definition.
Service Response. Large tracts of native prairie are needed
to recovery the APO.
~Qmm~nLi.Z.Predator control should be considered,
specifically avian and skunks.
Service Response. Skunk control is implemented on the refuge.
Proposed research will examine the relationship between
predator control and predator/prey relationships (buffer prey
species, alternative prey selection, etc.).
48