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Cougar Population Dynamics in Southern Utah

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We monitored size and composition of a southern Utah cougar (Felis concolor) population during 1979-87 to document the dynamics of this unhunted population and to test the hypothesis that cougars would regulate their density at a level below that set by prey abundance alone (Seidensticker et al. 1973). We captured cougars when detected during ongoing searches for sign in the study area. Resident adult cougar density remained relatively constant (0.37/100 km2) for the first 7 years but increased slightly in the last 2 years. Mule deer (Odocoileus hemionus), the cougar's primary prey, increased over the 9 years, but magnitude of this increase was unknown. Results supported the hypothesis that cougar density is set by environmental features other than prey abundance alone. Adult resident females bred as young as 17 months and produced litters that averaged 2.4 kittens at an interval of 24.3 months.
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Cougar Population Dynamics in Southern Utah
Author(s): Frederick G. Lindzey, Walter D. Van Sickle, Bruce B. Ackerman, Dan Barnhurst,
Thomas P. Hemker and Steven P. Laing
Source:
The Journal of Wildlife Management,
Vol. 58, No. 4 (Oct., 1994), pp. 619-624
Published by: Wiley on behalf of the Wildlife Society
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COUGAR POPULATION
DYNAMICS
IN SOUTHERN UTAH
FREDERICK
G. LINDZEY,
Wyoming
Cooperative
Fish
and Wildlife Research
Unit,
Box 3166, University
Station, Laramie,
WY
82071
WALTER D. VAN
SICKLE,
Wyoming
Cooperative
Fish
and Wildlife
Research
Unit,
Box 3166, University
Station,
Laramie,
WY
82071
BRUCE
B. ACKERMAN,'
Utah
Cooperative
Fish
and Wildlife
Research
Unit,
UMC
52, Utah State University, Logan,
UT 84321
DAN
BARNHURST,2
Utah
Cooperative
Fish
and Wildlife
Research
Unit,
UMC
52, Utah
State University, Logan,
UT
84321
THOMAS
P. HEMKER,3
Utah
Cooperative
Fish and Wildlife Research
Unit,
UMC
52, Utah State University, Logan,
UT 84321
STEVEN
P. LAING,4
Wyoming
Cooperative
Fish
and Wildlife Research
Unit,
Box 3166, University
Station, Laramie,
WY
82071
Abstract: We monitored size and composition
of a southern Utah cougar
(Felis concolor)
population
during
1979-87 to document the dynamics
of this unhunted
population
and to test the hypothesis
that
cougars
would
regulate their density at a level below that set by prey abundance alone (Seidensticker
et al. 1973). We
captured cougars
when detected during ongoing searches for sign in the study area. Resident adult cougar
density remained relatively constant (0.37/100 km2) for the first 7 years but increased
slightly in the last 2
years.
Mule deer (Odocoileus hemionus), the cougar's
primary
prey, increased over the 9 years,
but magnitude
of this increase was unknown. Results
supported
the hypothesis
that cougar density is set by environmental
features
other than prey abundance alone. Adult resident females bred as young as 17 months and produced
litters that averaged 2.4 kittens at an interval of 24.3 months. J. WILDL.
MANAGE.
58(4):619-624
Key words: cougar, Felis concolor, mountain lion, population
dynamics, reproduction,
Utah.
Management agencies face demands for ad-
ditional cougar-hunting opportunities, relief
from cougar depredation on domestic livestock,
and challenges of their cougar management
programs from the general public. Information
available to managers comes primarily from
short-term cougar research efforts often con-
ducted on populations exploited by hunting.
Hornocker's (1970) and Seidensticker et al.'s
(1973) research in Idaho provided insight into
the long-term dynamics of a cougar population.
They hypothesized that cougar populations were
capable of regulating their density and that this
density would ultimately be established on the
basis of factors other than prey density. Sex ra-
tios in most cougar populations appear to favor
females, but age composition often differs among
populations (Seidensticker et al. 1973, Shaw 1977,
Ashman et al. 1983, Logan 1983, Hemker et al.
1984, Hopkins et al. 1986).
We monitored size, composition, natality, and
emigration in an unhunted cougar population
in southern Utah to evaluate the hypothesis that
cougar populations could regulate their density
and to enable comparisons of population attri-
butes with those of other cougar populations.
We concurrently monitored mule deer popu-
lation size because of its potential influence on
cougar population dynamics.
We thank N. H. Hancock, D. Bunnell, J. A.
Roberson, and J. W. Bates for coordinating the
project through the Utah Division of Wildlife
Resources (UDWR). Primary funding was pro-
vided by the UDWR and administered by the
Wyoming and Utah Cooperative Fish and Wild-
life Research units. T. Rettberg and V. Judkins
served as pilots. A. J. Button (deceased), W. W.
Button, C. S. Mecham, and M. C. Mecham pro-
vided field assistance and functioned as hounds-
men.
STUDY AREA
The 4,500-km2 study area was located in Gar-
field and Kane counties in south-central Utah.
We used a core area of 1,900 km2 for population
analyses (population study area). The study area
was bordered on 3 sides by relatively treeless,
open areas that likely would not support cougars
(Laing and Lindzey 1991). Elevation in the area
ranged from 1,350 to 3,335 m. Climate was
characterized by moderately heavy snowfall in
' Present address: Florida Department of Natural
Resources,
Florida Marine Research
Institute,
100 8th
Avenue S.E., St. Petersburg,
FL 33701.
2 Present address: Utah Division of Wildlife Re-
sources,
Vernal, UT 84078.
3
Present address: Idaho Department of Fish and
Game, P.O. Box 25, Boise, ID 83707.
4 Deceased.
619
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620 COUGAR
POPULATION
DYNAMICS
* Lindzey et al. J. Wildl. Manage. 58(4):1994
winter, hot (Jul 9 = 24.5 C), dry summers with
occasional intense thunderstorms, and mild
spring and fall seasons. Annual precipitation,
primarily snowfall, averaged 18 cm at lower
elevations and 60 cm on high elevation plateaus
(Tew 1972). Vegetation and land uses in the
area are described in Lindzey et al. (1992).
Mule deer, the most common wild ruminant,
occurred at population levels (about 5,000) be-
low those of the 1960s (Hemker 1982). Elk
(Cervus elaphus) were introduced to the area
in 1977 and numbered 200-400 during the study.
Other potential cougar prey animals present in-
cluded black-tailed jackrabbit (Lepus califor-
nicus), snowshoe hare (L. americanus), moun-
tain cottontail (Sylvilagus nuttallii), desert
cottontail (S. audubonii), and smaller rodents.
METHODS
The area was closed to cougar hunting in 1979
to facilitate the study, but cougar hunting con-
tinued adjacent to the study area, and the study
area was hunted and trapped for other animals.
We conducted experimental hunts during win-
ters 1982-83 and 1983-84, removing 2 young,
nonresident cougars from the area (Barnhurst
1986).
Monitoring for population analyses began in
January 1979 and ended in 1987, during a re-
moval experiment (Lindzey et al. 1992). We
captured cougars using methods similar to those
described by Hornocker (1970) and Hemker et
al. (1984). We initially located cougars by
searching roads and trails for tracks and using
trained dogs while riding horses or walking off
the roaded portions of the study area. When a
cougar was treed we climbed the tree to within
5 m of the cougar to allow safe positioning of a
projectile syringe fired from a CO2-powered pis-
tol. We used a 1.00:0.15 mixture of ketamine
HCI and xylazine HCI for immobilization (Clark
et al. 1979). We tattooed ears with an identifi-
cation number and attached numbered ear tags.
We attached a collar containing a motion-sen-
sitive radio transmitter to each cougar. Kittens
(<1 yr old) were fitted with either expandable,
drop-off radio collars similar to those described
by Garcelon (1977) or radio collars simply tied
with cotton string, which allowed the collar to
fall off when the string rotted. We fitted older
kittens with adult-sized collars. There was little
neck growth in females after 6 months of age.
Beginning in 1980, we surgically removed a toe
(initially front, later hind) from adult, resident
cougars to enable track identification.
We used dental (Ashman et al. 1983) and
physical characteristics (Eaton and Velander
1977) and documented birth dates to determine
ages of captured cougars. We classified cougars
as resident, transient, or juvenile. Residents were
adult cougars (>1.5 yr old) that showed site
attachment (continuous use of a predictable area
for >6 months). We classified immigrants and
independent young of the study population as
transient until they met our definition of resi-
dent. Consequently, a cougar could be classified
transient 1 year and resident the next year.
Transients did not use predictable areas and did
not breed. We classified progeny of the resident
population as juvenile while they were still as-
sociated with their mothers.
We attempted to locate all radio-collared cou-
gars at least once a week from a fixed-wing
aircraft. Telemetry flights covered, as necessary,
the entire study area and adjacent areas. We
also located selected cougars several times a week
from the ground to obtain more detailed infor-
mation on movements, intraspecific associations,
and activity patterns. We monitored move-
ments of resident females for patterns that would
suggest they had kittens (e.g., frequent return
to the same area). We approached females sus-
pected of having kittens without dogs or cau-
tiously with less aggressive, younger dogs to lo-
cate the litter. When it was necessary to use
dogs to locate a suspected litter, we waited until
the litter was about 3 months old, an age at
which kittens could escape dogs if necessary.
We determined size and composition of the
study population by systematically searching the
population study area throughout the year, with
and without dogs, for evidence of new cougars
(Seidensticker et al. 1973, Hemker et al. 1984).
We searched all areas, including those occupied
by cougars, and searched the remainder of the
study area as well but with less intensity. We
captured cougars when detected. One to 4 per-
sonnel, including a full-time houndsman, were
present on the study area. Movement records of
radio-collared cougars and tracks of cougars
marked by surgical removal of a toe enhanced
sign interpretation. Observations of cougars or
their sign by persons working and trapping in
the area augmented our observations. Each win-
ter (Jan-Mar) we made population estimates, on
the basis of the number of radio-collared cou-
gars and their offspring and the number of doc-
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J. Wildl. Manage. 58(4):1994 COUGAR POPULATION DYNAMICS
* Lindzey et al. 621
umented, but unmarked, cougars present in the
area.
Mule deer abundance was indexed annually
with pellet group transects on the winter range
(Neff 1968, Ackerman 1982). We used 10-m2
circular plots spaced 10 paces apart along tran-
sects (usually 50 plots/transect). Although we
did not use permanent plots we fixed starting
point and direction for each transect. We sur-
veyed transects between May and August. We
established 5,176 plots on 94 transects by the
end of the third year. After the third year, we
reduced the number of transects to 46 (2,490
plots) that adequately represented the winter
range of deer within the area (Hemker et al.
1984). These 46 transects were subsequently sur-
veyed each year except in 1983. We calculated
an index to mule deer abundance by dividing
the number of pellet groups found on these 46
transects each year by number of plots, multi-
plying this number by 100, and then dividing
the product by the estimated number of days
deer were on winter range. We estimated time
deer spent on the winter range each year from
field observations. We also used success of mule
deer hunters and number of male deer har-
vested as indices of mule deer population trend
(Utah Div. Wildl. Resour. 1990). The deer herd
unit used in these analyses (51B; Utah Div. Wildl.
Resour. 1990) included about 90% of the study
area. Some deer that summered within this unit
likely migrated northward into the adjacent herd
unit during winter and thus were not sampled
with pellet-group transects. We had no indica-
tion, however, that the proportion of the pop-
ulation that migrated out of the herd unit (51B)
differed among years.
We measured annual change in mule deer
population indices by fitting straight lines
through their natural logarithms plotted against
years. We examined the relationship between
deer and cougar numbers with Spearman rank
order correlation analyses.
RESULTS
We monitored 72 radio-collared cougars dur-
ing the study for an average of 16.9 months (SD
= 17.3) each. Because some female progeny es-
tablished home ranges on the study area, lin-
eages of 3 of the original females were present
throughout the study. We documented fourth
filial generations in 2 female lineages and a third
filial generation in another.
Table 1. Size and composition
of a southern Utah cougar
population
estimated from captures, telemetry
records, and
sign of unmarked
cougars, 1979-87.
Adult
residents Tran- Total
Yeara M F Total Juv sients cougars
1979 2 6 8 7 0 15
1980 1 6 7 14 1 22
1981 1 5 6 11 2 19
1982 1 7 8 3 0 11
1983 0 7 7 6 1 14
1984 1 5 6 9 4 19
1985 1 6 7 5 10 24b
1986 4 6 10 9 6 25
1987 4 8 12 8 4 26b
a Annual survey period Jan-Mar.
b Two independent cougars of unknown status known to be present.
Size of the adult resident segment of the cou-
gar population changed little over the first 7
years but increased the last 2 (Table 1). This
increase resulted from immigration and estab-
lishment of males and an increase of 1 above
the long-term average of 7 adult females. Num-
bers of transients and kittens varied annually,
but there was no apparent trend in kitten num-
bers that would suggest synchronous breeding.
Three adult females (1 each in 1983, 1986, and
1987) and 5 kittens died during the study from
apparent capture-related injuries.
Natality
We observed 31 litters between 1979 and 1989
(we monitored the population for 2 additional
years during the removal experiment; Lindzey
et al. 1992). Litters were born in each month
except December, January, and March. A birth
peak in late summer and fall was apparent, with
6 litters born in August, 7 in September, and 11
in October. Other months had 1 birth, except
June during which there were 2 births. Average
size of 26 litters where we felt we had found all
kittens was 2.4 (SD = 0.8). Litter size ranged
from 1 (n = 4) to 4 (n = 1), with litters of 2 (n
= 9) and 3 (n = 12) most common. Sex ratio of
kittens in 14 litters from which all kittens were
sexed favored males (1.31 M:1.00 F).
Six females that were marked as kittens and
remained to establish home ranges on the area
first gave birth at a mean age of 26 months (SD
= 4.5, range 20-34). Assuming a 92-day gesta-
tion period (Eaton and Velander 1977), average
age at first breeding for these females was 23
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622 COUGAR POPULATION DYNAMICS
o Lindzey et al. J. Wildl. Manage. 58(4):1994
months (SD = 4.5), and the earliest a female
successfully bred was 17 months.
We documented interval between successive
litters on 11 occasions. On 3 occasions (12-, 13-,
and 16-month intervals) we felt all kittens in
the first litter had died before 1 year of age, and
the female had apparently bred again. On an-
other occasion, during the harvest experiment
(Lindzey et al. 1992), we translocated a female
between successive litters (29-month interval).
The remaining 7 intervals, where > 1 kitten sur-
vived > 1 year, averaged 24.3 months (SD = 6.8,
range 19-40).
Dispersal
Of 15 progeny of the population that carried
functioning radio collars at 16 months of age,
all 5 males dispersed from the area while 7 of
the 10 females remained and established home
ranges. Average straight-line distance from the
natal ranges of the 5 males to where they were
killed was 123 km (SD = 75, range 39-241 km).
They died an average of 9.8 months (SD = 6.5)
after leaving the area. One of the 2 females that
dispersed was killed 66 km from her natal range
when she was 2.5 years old (11-12 months post-
dispersal) and the other 47 km distant when she
was 12.5 years old.
Mule Deer
Population
The pellet group index, hunter success, and
number of male mule deer harvested suggested
an increasing mule deer population over the
study. Hunter success in 1986 was over twice
what it had been in 1978, and deer harvest was
3 times as great (Utah Div. Wildl. Resour. 1990).
Pellet group index, harvest, and hunter success
increased annually an average of 16.0, 1.9, and
1.3%, respectively. The relationship between the
pellet group index and cougar numbers over the
study was weak (r, = 0.602, P < 0.005). Deer
and cougar numbers were more poorly related
over the first 7 years (r, = 0.216, P >0.50).
DISCUSSION
The resident adult segment of the Boulder-
Escalante cougar population remained relative-
ly constant in size over the first 7 years of the
study. Sufficient numbers of transients were
present over this period to have provided for
growth of the population had they established
residency. Removal of 2 young, transient cou-
gars from the population during winters 1982-
83 and 1983-84 likely had little influence on
population dynamics because of the abundance
of transients in the population during the 7 years.
The increase in resident adults in the last 2 years
(1986-87) resulted from recruitment of immi-
grating males and an increase of 1 female over
the long-term average of 7 and brought the adult
sex ratio (1987 = 1 M:2 F) close to that observed
in other populations (1:2, Seidensticker et al.
1973; 1:2 = min. and 1:3 max., Logan 1983).
Resident adult numbers returned to the higher
1987 level, with the possible exception of 1 male,
9 months after the population was experimen-
tally reduced by 27%. With the exception of 1
female, resident adults were at the 1987 level 2
years later (Lindzey et al. 1992), suggesting the
resident adult segment of the population had
stabilized at this higher level.
We believe that continual reconnaissance of
the area with and without trained dogs, our
ability to identify marked residents from tracks
even if their transmitter had failed, and moni-
toring of radio-collared cougars enabled accu-
rate annual enumeration of resident adults. Only
once did we capture a female of an age that
would indicate we may have missed her the
previous year. However, we undoubtedly did
not capture all transients that were present dur-
ing a given year. We found tracks of small,
unmarked cougars only once despite increased
search efforts following the initial sighting, sug-
gesting the cougar had simply moved through
the study area. Young cougars radiocollared as
transients, but not independent progeny of study
area residents, occasionally left the area. Kitten
numbers also may have been underestimated in
some years because we did not always find a
litter when a female's movement pattern or her
earlier association with a male suggested she had
young.
Reproduction remained high during the study,
undoubtedly facilitated in part by the popula-
tion's regulation of its own density. Average lit-
ter size (2.4) in the population was only slightly
lower than the fetal litter size of 2.8 reported
by Robinette et al. (1961) and the captive cougar
litter size of 2.6 documented by Eaton and Ve-
lander (1977). Litter size at birth on our study
area may actually have been larger than 2.4
because we did not investigate about 65% of the
litters until they were >3 months old (Hemker
et al. 1986), and some kittens may have died by
this time. The interval we observed between
litters (24.3 months) was also similar to that ob-
served in other cougar populations (Anderson
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J. Wildl. Manage. 58(4):1994 COUGAR
POPULATION
DYNAMICS
* Lindzey et al. 623
1983). The shorter interval between litters of
the 3 females that had lost their litters before
kittens were 1 year old suggests females may
breed soon after losing a litter, as predicted by
Seidensticker et al. (1973). While the average
age of first breeding is similar to that observed
in other cougar populations (Anderson 1983:31),
1 female bred when 17 months old. This female
had remained and established in her dead moth-
er's home range. Rapid establishment and early
breeding by progeny of residents undoubtedly
contributes to resiliency in cougar populations.
Immigrants would not likely replace lost resi-
dents as quickly or breed as soon as recruited
progeny (Laing and Lindzey 1993).
Earlier, we hypothesized that the cougar pop-
ulation would increase as the mule deer popu-
lation grew (Hemker et al. 1984) because cougar
and deer populations were apparently below
historic levels when we began our study. Indices
of deer numbers and our general observations
indicated that the deer population had grown
over our study, although we could not document
the actual magnitude of the increase. Number
of resident adult cougars, however, generally
remained stable through this period, and we
demonstrated only a weak relationship between
cougar and deer numbers. While the observa-
tions appear to support Seidensticker et al.'s
(1973) thesis that the land tenure system of cou-
gars maintains the density of breeding adults
below a level set by food supply alone, it is
possible the increase in deer numbers on our
study area was insufficient to provide an ade-
quate test of their hypothesis.
MANAGEMENT IMPLICATIONS
Factors that can be important in determining
cougar density will likely change over the rel-
atively long period necessary to monitor con-
current changes in cougar and prey populations,
making it difficult to define the relationship be-
tween cougars and their prey under natural con-
ditions. Intuitively, one would not expect cougar
population dynamics to be independent of those
of their principal prey. The few studies that
have examined this relationship (Hornocker
1970, Seidensticker et al. 1973, this study) may
simply have been conducted when prey was
abundant enough that other features of the en-
vironment set allowable resident cougar densi-
ties. Experimental manipulations of prey pop-
ulations would enable examination of the
relationship between cougar and prey at the
extremes of the prey abundance spectrum and
reduce the potentially confounding effect of
other variables if done over a short period.
LITERATURE CITED
ACKERMAN, B. B. 1982. Cougar
predation
and eco-
logical energetics in south-central Utah. M.S.
Thesis, Utah State Univ., Logan. 95pp.
ANDERSON, A. E. 1983. A critical review of liter-
ature on puma (Felis concolor). Colorado Div.
Wildl. Spec. Rep. 54, Denver. 99pp.
ASHMAN,
D. L., G. C. CHRISTENSEN,
M. C. HESS, G.
K. TUSKAMOTO, AND M. S. WICKERSHAM. 1983.
The mountain lion in Nevada. Nevada Dep.
Wildl. Rep. 4-48-15, Reno. 75pp.
BARNHURST,
D. 1986. Vulnerability
of cougars to
hunting. M.S. Thesis, Utah State Univ., Logan.
66pp.
CLARK, W., D. A. JESSUP, AND A. ADAMS. 1979.
Animal restraint handbook. California
Dep. Fish
and Game, Sacramento.
113pp.
EATON,
R. L., AND K. A. VELANDER. 1977. Repro-
duction in the puma: biology, behavior and on-
togeny. World's Cats 3:45-70.
GARCELON,
D. K. 1977. An expandable drop-off
transmitter collar for young
mountain lions. Calif.
Fish and Game 63:185-189.
HEMKER,
T. P. 1982. Population
characteristics
and
movement patterns
of cougars
in southern
Utah.
M.S. Thesis, Utah State Univ., Logan. 59pp.
1- , F. G. LINDZEY,
AND
B. B. ACKERMAN.
1984.
Population characteristics and movement pat-
terns of cougars
in southern Utah. J. Wildl. Man-
age. 33:457-464.
HOPKINS,
R. A., M. J. KUTILEK,
AND
G. L. SHREVE.
1986. Density and home range characteristics
of mountain lions in the Diablo Range of Cali-
fornia. Pages 223-235 in S. D. Miller and D. D.
Everett, eds. Cats of the world:
biology, conser-
vation and management. Natl. Wildl. Fed.,
Washington,
D.C.
HORNOCKER,
M. G. 1970. An analysis
of mountain
lion predation upon
mule deer in the Idaho
Prim-
itive Area. Wildl. Monogr.
21. 39pp.
LAING, S. P., AND F. G. LINDZEY. 1991. Cougar
habitat
selection
in south-central
Utah. Pages
27-
37 in C. E. Braun, ed. Mountain lion-human
interaction. Colorado
Div. Wildl., Denver.
, AND- . 1993. Patterns of replacement
of resident
cougars
in southern Utah. J.
Mammal.
74:1056-1058.
LINDZEY, F. G., W. D. VAN SICKLE, S. P. LAING, AND
C. S. MECHAM. 1992. Cougar population re-
sponse to manipulation
in southern
Utah. Wildl.
Soc. Bull. 20:224-227.
LOGAN,
K. A. 1983. Mountain
lion habitat
and pop-
ulation characteristics
in the Big Horn
Mountains
of north-central
Wyoming. M.S. Thesis, Univ.
Wyoming, Laramie. 67pp.
NEFF, D. J. 1968. The pellet-group
count technique
for big game trend, census, and distribution:
a
review. J. Wildl. Manage.
32:597-614.
ROBINETTE, W. L., J. S. GASHWILER, AND O. W.
MoRRIs. 1961. Notes on cougar productivity
and life history. J. Mammal. 42:204-217.
This content downloaded from 164.165.235.3 on Tue, 21 Oct 2014 17:06:24 PM
All use subject to JSTOR Terms and Conditions
624 COUGAR
POPULATION
DYNAMICS
o Lindzey et al. J. Wildl. Manage. 58(4):1994
SEIDENSTICKER,
J. C., M. G. HORNOCKER, W. V.
WILES, AND J. P. MESSICK. 1973. Mountain
lion
social organization
in the Idaho Primitive Area.
Wildl. Monogr.
35. 60pp.
SHAW, H. G. 1977. Impacts of mountain lions on
mule deer and cattle. Pages 17-32 in R. L. Phil-
lips and C. J. Jonkel, eds. Proc. 1975 predator
symposium.
Mont.
For.
Conserv.
Exp.
Stn.,
School
For., Univ. Montana,
Missoula.
TEW,
R. K. 1972. Land systems inventory on the
Escalante
Ranger
District,
Dixie National
Forest.
U.S. For. Serv.
Tech. Rep., Cedar
City, Ut. 95pp.
UTAH DIVISION OF WILDLIFE RESOURCES. 1990.
Utah big game investigations and management
recommendations, 1989-90. Utah Div. Wildl.
Resour.
Publ. 90-1, Salt Lake City. 116pp.
Received 7 August 1992.
Accepted 29 March 1994.
Associate Editor: Sauer.
IMPACT
OF A SARCOPTIC MANGE EPIZOOTIC
ON
A COYOTE POPULATION
DANNY
B. PENCE,
Department
of Pathology,
Texas Tech University
Health
Sciences Center, Lubbock,
TX
79430
LAMAR
A. WINDBERG, USDA/APHIS,
Denver Wildlife Research
Center,
Utah State University,
Logan,
UT 84322
Abstract: Although
sarcoptic mange is a mite (Sarcoptes
scabiei) infection that occurs as periodic epizootics
in wild canids,
the effect of this disease on populations
has not been explained.
We collected data from 1,489
coyotes (Canis latrans) during 1974-91 in southern Texas and examined the effect of a sarcoptic mange
epizootic on the coyote population. Mange appeared in 1975, peaked during spring 1980 (69%
of coyotes
infected), and then decreased until absent among coyotes collected in 1991. The epizootic encompassed
60,000 km2
in southern Texas during 1982-89. Adult males were more (P < 0.001) frequently
infected than
other age-sex classes during the stationary phase of peak prevalence. Mange prevalence in juvenile males
increased
(P < 0.01) overwinter
during the stationary
and decline phases of the epizootic. There were more
cases of severe mange among adult males (P < 0.01) during the stationary
than the decline phase. Reduced
ovulation (P = 0.04) and pregnancy rates (P = 0.03) were associated
with greater mange severity in adult
females. Usually, coyotes with severe mange had less (P < 0.05) internal fat. We suggest that this epizootic
was initiated
by the appearance
of a virulent
strain
of S. scabiei in the host population, spread
of the epizootic
was enhanced by high host population densities but moderated by the social organization
of coyotes, and
decline of the epizootic resulted from selection for mange-resistant
individuals in the host population.
Understanding
the effect of diseases on wildlife populations requires long-term analysis
of host population
dynamics, with attention to other relevant factors such as behavior. J. WILDL. MANAGE.
58(4):624-633
Key words: Canis latrans, coyote, epizootic disease, population dynamics, Sarcoptes scabiei, sarcoptic
mange, Texas.
Pence et al. (1983) documented the effects of
a sarcoptic mange epizootic on a coyote popu-
lation in southern Texas over 7 years (1975-81).
Although the mortality rate among mange-in-
fected individuals was greater than among un-
infected coyotes during 1979-80, it was com-
pensatory with overall mortality in the
population (Pence et al. 1983).
The high-density coyote population (0.9-2.0
coyotes/km2 in spring) in southern Texas had a
well-developed social organization (Andelt 1985,
Windberg and Knowlton 1988) and experienced
light exploitation by humans (Windberg et al.
1985). The diverse food base was consistently
abundant (Brown 1977, Windberg and Mitchell
1990). In conjunction with other studies, we
monitored the prevalence and severity of mange
in this population during 1981-91. We present
data for the duration of the epizootic to further
assess its dynamics and effect on the coyote pop-
ulation. Our objectives were to (1) describe sta-
tionary through decline phases of the mange
epizootic (1979-91), (2) compare the severity of
mange infection across temporal (seasons) and
host (age and sex) factors over the latter years
of the epizootic, and (3) reassess the effect of
Pence et al. (1983) documented the effects of
a sarcoptic mange epizootic on a coyote popu-
lation in southern Texas over 7 years (1975-81).
Although the mortality rate among mange-in-
fected individuals was greater than among un-
infected coyotes during 1979-80, it was com-
pensatory with overall mortality in the
population (Pence et al. 1983).
The high-density coyote population (0.9-2.0
coyotes/km2 in spring) in southern Texas had a
well-developed social organization (Andelt 1985,
Windberg and Knowlton 1988) and experienced
light exploitation by humans (Windberg et al.
Received 7 August 1992.
Accepted 29 March 1994.
Associate Editor: Sauer.
624 COUGAR
POPULATION
DYNAMICS
o Lindzey et al. J. Wildl. Manage. 58(4):1994
Escalante
Ranger
District,
Dixie National
Forest.
U.S. For. Serv.
Tech. Rep., Cedar
City, Ut. 95pp.
UTAH DIVISION OF WILDLIFE RESOURCES. 1990.
Utah big game investigations and management
recommendations, 1989-90. Utah Div. Wildl.
Resour.
Publ. 90-1, Salt Lake City. 116pp.
1985). The diverse food base was consistently
abundant (Brown 1977, Windberg and Mitchell
1990). In conjunction with other studies, we
monitored the prevalence and severity of mange
in this population during 1981-91. We present
data for the duration of the epizootic to further
assess its dynamics and effect on the coyote pop-
ulation. Our objectives were to (1) describe sta-
tionary through decline phases of the mange
epizootic (1979-91), (2) compare the severity of
mange infection across temporal (seasons) and
host (age and sex) factors over the latter years
of the epizootic, and (3) reassess the effect of
SEIDENSTICKER,
J. C., M. G. HORNOCKER, W. V.
WILES, AND J. P. MESSICK. 1973. Mountain
lion
social organization
in the Idaho Primitive Area.
Wildl. Monogr.
35. 60pp.
SHAW, H. G. 1977. Impacts of mountain lions on
mule deer and cattle. Pages 17-32 in R. L. Phil-
lips and C. J. Jonkel, eds. Proc. 1975 predator
symposium.
Mont.
For.
Conserv.
Exp.
Stn.,
School
For., Univ. Montana,
Missoula.
TEW,
R. K. 1972. Land systems inventory on the
IMPACT
OF A SARCOPTIC MANGE EPIZOOTIC
ON
A COYOTE POPULATION
DANNY
B. PENCE,
Department
of Pathology,
Texas Tech University
Health
Sciences Center, Lubbock,
TX
79430
LAMAR
A. WINDBERG, USDA/APHIS,
Denver Wildlife Research
Center,
Utah State University,
Logan,
UT 84322
Abstract: Although
sarcoptic mange is a mite (Sarcoptes
scabiei) infection that occurs as periodic epizootics
in wild canids,
the effect of this disease on populations
has not been explained.
We collected data from 1,489
coyotes (Canis latrans) during 1974-91 in southern Texas and examined the effect of a sarcoptic mange
epizootic on the coyote population. Mange appeared in 1975, peaked during spring 1980 (69%
of coyotes
infected), and then decreased until absent among coyotes collected in 1991. The epizootic encompassed
60,000 km2
in southern Texas during 1982-89. Adult males were more (P < 0.001) frequently
infected than
other age-sex classes during the stationary phase of peak prevalence. Mange prevalence in juvenile males
increased
(P < 0.01) overwinter
during the stationary
and decline phases of the epizootic. There were more
cases of severe mange among adult males (P < 0.01) during the stationary
than the decline phase. Reduced
ovulation (P = 0.04) and pregnancy rates (P = 0.03) were associated
with greater mange severity in adult
females. Usually, coyotes with severe mange had less (P < 0.05) internal fat. We suggest that this epizootic
was initiated
by the appearance
of a virulent
strain
of S. scabiei in the host population, spread
of the epizootic
was enhanced by high host population densities but moderated by the social organization
of coyotes, and
decline of the epizootic resulted from selection for mange-resistant
individuals in the host population.
Understanding
the effect of diseases on wildlife populations requires long-term analysis
of host population
dynamics, with attention to other relevant factors such as behavior. J. WILDL. MANAGE.
58(4):624-633
Key words: Canis latrans, coyote, epizootic disease, population dynamics, Sarcoptes scabiei, sarcoptic
mange, Texas.
This content downloaded from 164.165.235.3 on Tue, 21 Oct 2014 17:06:24 PM
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... After first breeding, females normally breed soon after loss of kittens or dispersal of their litter (Lindzey 1987) causing birth intervals to vary. Birth intervals vary but range between 12 and 24 months (Hornocker 1970, Lindzey 1987, Lindzey et al. 1994, Robinette et al. 1961. ...
... Historically, cougar predation has not been implicated as a strong limiting factor on elk populations (Ruth and Murphy 2010b). Predation by cougars did not prevent elk populations from increasing in Idaho (Hornocker 1970) or Utah (Lindzey et al. 1994). Cougars are known to kill adult elk, but predation by cougars on elk is typically focused on juveniles (Knopff et al. 2010, Clark et al. 2014. ...
... comm. A. Rabinowitz, director of science and exploration, Wildlife Conservation society). Puma populations can withstand an arumal harvest of 10-25% ofthe total population as long as habitat and prey populations are adequate (Lindzey et al. 1992(Lindzey et al. , 1994. Tiger numbers in India doubled within 10 years of the establishment of several large tiger reserves (Nowell & Jackson 1996). ...
Thesis
p>Camera trap data were used for the first time to test hypotheses about the mechanisms of coexistence of jaguars and pumas and about the social system of jaguars by investigating their spatio-temporal distribution. It was shown that jaguars and pumas were predominantly nocturnal with substantial inter-specific spatial overlap but did not occupy the same space at the same time. It was also found that jaguars leave forest trails more frequently than pumas. Jaguar captures were strongly biased towards males, due in part to males being more active and moving further than females. The spatial distribution of male jaguars was characterised by extensive range overlap. There was no stability in occupancy, or evidence of avoidance between males. The role of scrape-marking behaviour in jaguar and puma social systems was investigated. Scrapes were clustered along trails in spatially stable ‘hot-spots’. Monitoring through time revealed that scrapes elicit counter-scraping nearby, probably be conspecifics. Camera data showed that scrapes were mostly associated with puma captures. There was no evidence that higher scrape frequencies were associated with particular individuals. Combined sign and camera surveys were deployed to investigate whether camera trap data can measure the relative abundance of prey species of jaguars and pumas. Pre species varied greatly in their use of trails, rendering camera traps unreliable for applications of prey. A total of 450 scats were collected over 3 years to determine jaguar and puma diet. This is one of the largest diet studies on large neotropical cats. Spatial and temporal variation in diet was found across the CBWS, indicating that short-term diet studies in small areas should be interpreted with care.</p
... Laing and Lindzey (1993) found that immigrant Utah pumas would not replace lost residents and breed as young as recruited progeny. The minimum age at sexual maturity in female Florida panthers is almost identical to a female Utah puma that remained in her deceased mother's territory (Lindzey et al. 1994). By contrast, the minimum age at sexual maturity in male Florida panthers was older than a male Montana puma in a male-hunted population (Onorato et al. 2011). ...
Article
Recognizing individual variation in body growth characteristics and size at sexual maturity is of particular interest because they indicate a potential source of variance in survival and reproductive fitness. I used the Richards group of unified models method to examine body growth characteristics, mass at sexual maturity, and development of sexual size dimorphism in Florida panthers (Puma concolor coryi). A larger asymptotic body size and mass at sexual maturity in males resulted from a greater instantaneous growth rate across the life span and longer duration of growth than in females. Juvenile males attained larger body mass than female counterparts before achieving independence and sexual maturity, suggesting that a greater instantaneous growth rate developed from precopulatory intrasexual selection. Body mass growth rapidly decreased proximate to the minimum age at first conception in both sexes, suggesting that energetic costs of reproduction inhibited additional growth. Intrasexual selection among males to enhance fighting ability and promote access to a territory and mates is implicated as the cause for sexual size dimorphism, together with more direct underlying energetic costs of reproduction in females. The results provide uniform sex-specific body mass-at-age growth and mass at sexual maturity statistics for comparison with other puma populations and reference values to implement measurable criteria to evaluate trends in Florida panther population health.
Article
We investigated effects of regulated hunting on a puma (Puma concolor) population on the Uncompahgre Plateau (UPSA) in southwestern Colorado, USA. We examined the hypothesis that an annual harvest rate averaging 15% of the estimated number of independent individuals using the study area would result in a stable or increasing abundance of independent pumas. We predicted hunting mortality would be compensated by 1) a reduction in other causes of mortality, thus overall survival would stay the same or increase; 2) increased reproduction rates; or 3) increased recruitment of young animals. The study occurred over 10 years (2004–2014) and was designed with a reference period (years 1–5; i.e., RY1–RY5) without puma hunting and a treatment period (years 6–10; i.e., TY1–TY5) with hunting. We captured and marked pumas on the UPSA and monitored them year‐round to examine their demographics, reproduction, and movements. We estimated abundance of independent animals using the UPSA each winter during the Colorado hunting season from reference year 2 (RY2) to treatment year 5 (TY5) using the Lincoln‐Petersen method. In addition, we surveyed hunters to investigate how their behavior influenced harvest and the population. We captured and marked 110 and 116 unique pumas in the reference and treatment periods, respectively, during 440 total capture events. Those animals produced known‐fate data for 75 adults, 75 subadults, and 118 cubs, which we used to estimate sex‐ and life stage‐specific survival rates. In the reference period, independent pumas more than doubled in abundance and exhibited high survival. Natural mortality was the major cause of death to independent individuals, followed by other human causes (e.g., vehicle strikes, depredation control). In the treatment period, hunters killed 35 independent pumas and captured and released 30 others on the UPSA. Abundance of independent pumas using the UPSA declined 35% after 4 years of hunting with harvest rates averaging 15% annually. Harvest rates at the population scale, including marked independent pumas with home ranges exclusively on the UPSA, overlapping the UPSA, and on adjacent management units were higher, averaging 22% annually in the same 4 years leading to the population decline. Adult females comprised 21% of the total harvest. The top‐ranked model explaining variation in adult survival () indicated a period effect interacting with sex. Annual adult male survival was higher in the reference period ( = 0.96, 95% CI = 0.75–0.99) than in the treatment period ( = 0.40, 95% CI = 0.22–0.57). Annual adult female survival was 0.86 (95% CI = 0.72–0.94) in the reference period and 0.74 (95% CI = 0.63–0.82) in the treatment period. The top subadult model showed that female subadult survival was constant across the reference and treatment periods ( = 0.68, 95% CI = 0.43–0.84), whereas survival of subadult males exhibited the same trend as that of adult males: higher in the reference period ( = 0.92, 95% CI = 0.57–0.99) and lower in the treatment period ( = 0.43, 95% CI = 0.25–0.60). Cub survival was best explained by fates of mothers when cubs were dependent (mother alive = 0.51, 95% CI = 0.35–0.66; mother died = 0.14, 95% CI = 0.03–0.34). The age distribution for independent pumas skewed younger in the treatment period. Adult males were most affected by harvest; their abundance declined by 59% after 3 hunting seasons and we did not detect any males >6 years old after 2 hunting seasons. Pumas born on the UPSA that survived to subadult stage exhibited both philopatry and dispersal. Local recruitment and immigration contributed to positive growth in the reference period, but recruitment did not compensate for the losses of adult males and partially compensated for losses of adult females in the treatment period. Average birth intervals were similar in the reference and treatment periods (reference period = 18.3 months, 95% CI = 15.5–21.1; treatment period = 19.4 months, 95% CI = 16.2–22.6), but litter sizes (reference period = 2.8, 95% CI = 2.4–3.1; treatment period = 2.4, 95% CI = 2.0–2.8) and parturition rates (reference period = 0.63, 95% CI = 0.49–0.75; treatment period = 0.48, 95% CI = 0.37–0.59) declined slightly in the treatment period. Successful hunters used dogs, selected primarily males, and harvested pumas in 1–2 days (median). We found that an annual harvest rate at the population scale averaging 22% of the independent pumas over 4 years and with >20% adult females in the total harvest greatly reduced abundance. At this scale, annual mortality rates of independent animals from hunting averaged 6.3 times greater than from all other human causes and 4.6 times greater than from all natural causes during the population decline. Hunting deaths were largely additive and reproduction and recruitment did not compensate for this mortality source. Hunters generally selected male pumas, resulting in a decline in their survival and abundance, and the age structure of the population. We recommend that regulated hunting in a source‐sink structure be used to conserve puma populations, provide sustainable hunting opportunities, and address puma‐human conflicts. © 2021 The Wildlife Society. Investigamos los efectos de la cacería regulada en la población de pumas (Puma concolor) de la Uncompahgre Plateau (UPSA) en el suroeste de Colorado, USA. Exploramos la hipótesis de que una cosecha anual con una tasa promedio del 15% del número estimado de pumas independientes que están usando el área de estudio resultaría en una abundancia estable o un incremento de pumas independientes. Nuestra predicción de que la mortalidad por cacería seria compensada por: 1) una reducción en otras causas de mortalidad, por lo tanto, la supervivencia se mantendría igual o incrementaría; 2) un incremento en la tasa reproductiva; o 3) un incremento en el reclutamiento de pumas jóvenes. Este estudio se llevó a cabo a lo largo de 10 años (2004–2014) y fue diseñado con un periodo de referencia (años 1 al 5; RY1–RY5) sin cacería de pumas y un periodo de tratamiento (años 6–10; i.e., TY1–TY5) con cacería de pumas. Capturamos y marcamos pumas en la UPSA y se llevó a cabo el monitoreo a lo largo de todo el año para examinar la demografía, reproducción y movimientos de los pumas. Estimamos la abundancia de pumas independientes que usaban la UPSA cada invierno durante la estación de cacería de pumas en Colorado usando el año 2 (RY2) como referencia al año de tratamiento 5 (TY5) usando el método de Lincoln‐Petersen. Adicionalmente, llevamos a cabo prospecciones con cazadores para investigar como el comportamiento de los cazadores influía la cosecha y la población de pumas. Capturamos y marcamos un total de 110 y 116 pumas únicos dentro del periodos de referencia y de tratamiento, respectivamente, a lo largo de un total de 440 eventos de captura. Esos pumas produjeron datos de mortalidad con información conocida para 75 adultos, 75 sub‐adultos y 118 cachorros, con los cuales se estimaron tasas de supervivencia específicas por sexo y etapas de vida. En el periodo de referencia la abundancia de pumas independientes se incrementó a más del doble y exhibieron una supervivencia alta. La mortalidad natural fue la mayor causa de muerte en pumas independientes, seguida de causas producidas por seres humanos (e.g. atropellamientos, control de depredadores). En el periodo de tratamiento, los cazadores mataron 35 pumas independientes, adicionalmente capturaron y dejaron en libertad a 30 pumas en la UPSA. La abundancia de pumas independientes se redujo en un 35% después de 4 años de cacería con tasas de aprovechamiento con un promedio anual de 15% en la UPSA. Las tasas de aprovechamiento a la escala de población incluyendo pumas independientes marcados con ámbitos hogareños exclusivos dentro de la UPSA, con sobreposición en la UPSA y en unidades adyacentes de manejo fueron mayores, en promedio 22% anualmente durante los mismos 4 años que llevaron a la población al declive. Las hembras adultas comprendieron 21% de la cosecha total. El mejor modelo que explicaba la variación en la supervivencia () de los adultos indicaba un efecto del periodo interactuando con el sexo. La supervivencia anual de los machos fue más alta durante el periodo de referencia ( = 0.96, 95% CI = 0.75–0.99) que durante el periodo de tratamiento ( = 0.40, 95% CI = 0.22–0.57). La supervivencia anual de las hembras fue 0.86 (95% CI = 0.72–0.94) en el periodo de referencia y 0.74 (95% CI = 0.63–0.82) durante el tratamiento. El mejor modelo de supervivencia en hembras sub‐adultas, mostro que la supervivencia fue constante a través de los periodos de referencia y tratamiento ( = 0.68, 95% CI = 0.43–0.84), donde la supervivencia de los machos sub‐adultos exhibió el mismo patrón de supervivencia de los machos adultos: más alta en el periodo de referencia ( = 0.92, 95% CI = 0.57–0.99) y menor en el periodo de tratamiento ( = 0.43, 95% CI = 0.25–0.60). La supervivencia de los cachorros se explica mejor por el destino de sus madres, cuando estos son dependientes (madres vivas = 0.51, 95% CI = 0.35–0.66; madres muertas = 0.14, 95% CI = 0.03–0.34). La distribución por edades de los pumas independientes estuvo sesgada a animales jóvenes durante el periodo de tratamiento. Los machos adultos fueron los más afectados por el aprovechamiento, su abundancia se redujo en un 59% después de 3 temporadas de cacería, y una ausencia de machos >6 años de edad después de 2 temporadas de cacería. Los pumas nacidos en la UPSA que sobrevivieron a la etapa sub‐adulta exhibieron características filopátricas y de dispersión. El reclutamiento local y la inmigración contribuyeron al crecimiento positivo en el periodo de referencia. Sin embargo, el reclutamiento no compenso por la pérdida de machos adultos y parcialmente compenso por la pérdida de hembras durante el periodo de tratamiento. El intervalo promedio entre nacimientos fue similar entre los periodos de referencia y tratamiento (periodo de referencia = 18.3 meses, 95% CI = 15.5–21.1; periodo de tratamiento = 19.4 meses, 95% CI = 16.2–22.6), mientras que el tamaño de camada (periodos de referencia = 2.8, 95% CI = 2.4–3.1; periodo de tratamiento = 2.4, 95% CI = 2.0–2.8) y las tasas de parición (periodo de referencia = 0.63, 95% CI = 0.49–0.75; periodo de tratamiento = 0.48, 95% CI = 0.37–0.59) declinaron ligeramente durante el periodo de tratamiento. Cazadores exitosos de pumas usaron perros, seleccionaron fundamentalmente machos y cosecharon pumas en 1−2 días (mediana). Encontramos a la escala de población una tasa de aprovechamiento anual de 22% del número de pumas independientes en un periodo de 4 años y donde >20% de hembras adultas en la cosecha total redujeron en cantidad la abundancia de pumas. A esta escala, las tasas anuales de mortalidad de los pumas independientes por caceria fueron en promedio 6.3 veces mayores que todas las otras causas producidas por seres humanos, y 4.6 veces mayores que todas las causas de mortalidad natural durante la reducción en la población. La mortalidad por cacería era aditiva y la reproducción y el reclutamiento no compensaron a la mortalidad por cacería. Encontramos que los cazadores de pumas seleccionaron pumas machos, resultando en una reducción de la supervivencia, abundancia de machos y la estructura de edades dentro de la población. Recomendamos que la cacería regulada con base en una estructura poblacional de fuente‐sumidero puede ser utilizada para conservar a las poblaciones de pumas, proporcionando oportunidades para la cacería sustentable de pumas y redirigir el conflicto entre pumas y seres humanos. Nous avons examiné les effets d’une chasse régulée sur une population de puma (Puma concolor) dans le plateau de l’Uncompahgre (UPSA) dans le sud‐ouest du Colorado. Nous avons examiné l’hypothèse qu’un taux annuel de récolte de 15% du nombre estimé de pumas indépendants utilisant l’aire d’étude maintiendrait l’abondance ou accroîtrait l’abondance de pumas. Nous avons prédit que la mortalité par la chasse serait compensée par: 1) une réduction des autres causes de mortalité, entrainant une augmentation ou stabilisation de la survie; 2) une augmentation du taux de reproduction; ou 3) une augmentation du recrutement de jeunes individus. L’étude a été conduit durant, et a été construite autour d’une période de référence (années 1 à 5) sans chasse aux pumas et une période de traitement (années 6 à 10) avec une chasse aux pumas. Nous avons capturé et marqué des pumas dans l’aire d’étude (UPSA) et les avons suivis toute l’année pour récolter des données concernant leur démographie, reproduction et mouvement. L’abondance de pumas indépendants a été estimée dans l’USPA à chaque hiver durant la saison de chasse aux pumas au Colorado de l’année de référence 2 (RY2) à l’année de traitement 5 (TY5) en utilisant la méthode de Lincoln‐Petersen. De plus, nous avons sondé les chasseurs afin d’apprendre comment leur comportement influençait la récolte et la population de puma. Durant les périodes de référence et traitement, 110 et 116 pumas ont respectivement été capturés et marqués, durant 440 évènements de capture. Ces pumas ont produit des données dont le sort est connu pour 75 adultes, 75 subadultes, et 118 juvéniles qui ont été utilisés afin de modéliser le taux de survie de chaque sexe et groupe d’âge. Durant la période de référence, l’abondance des pumas indépendants a plus que doublé en abondance et montré un haut taux de survie. La mortalité naturelle était la cause principale de décès, suivie par les mortalités reliées à l’humain. Durant la période de traitement, les chasseurs ont tué 35 pumas indépendants et capturé puis relâché 30 pumas. L’abondance de pumas indépendants a décliné de 35% après 4 années de chasse avec des taux de récolte moyennant 15% dans l’UPSA. Les taux de récoltes à l’échelle de la population incluant des individus dont le domaine vital était à l’intérieur de l’USPA, chevauchant l’USPA, ou en périphérie de l’USPA étaient plus élevés et approchaient 22% durant les quatre années précédant le déclin de la population. Les femelles adultes représentaient 21% de la récolte total. Le meilleur modèle expliquant la variation dans la survie () des adultes incluait un effet de la période en interaction avec le sexe. Le taux de survie des mâles adultes était plus élevé durant la période de référence ( = 0.96, 95% CI = 0.75–0.99) que durant la période de traitement ( = 0.40, 95% CI = 0.22–0.57). Le taux de survie des femelles adultes était de 0.86 (95% CI = 0.72–0.94) durant la période de référence et de 0.74 (95% CI = 0.63–0.82) durant la période de traitement. Le meilleur modèle du taux de survie des femelles subadultes a démontré que la survie était constante entre les deux périodes de traitement ( = 0.68, 95% CI = 0.43–0.84) alors que le taux de survie des mâles subadultes a montré la même tendance que les mâles adultes: plus élevé durant la période de référence ( = 0.92, 95% CI = 0.57–0.99) que durant la période de traitement ( = 0.43, 95% CI = 0.25–0.60). Le taux de survie des petits était le mieux expliqué par le sort de la mère alors que les petits étaient dépendants (mère en vie = 0.51, 95% CI = 0.35–0.66; mère en vie = 0.14, 95% CI = 0.03–0.34). La structure des âges des pumas indépendants a décliné durant la période de traitement. Les mâles adultes étaient les plus affectés par la récolte, leur abondance a décliné de 59% après trois saisons de chasse et aucun individu de plus de 6 ans n’était présent après deux saisons de chasse. Les pumas nés dans l’UPSA qui ont survécu au stage subadulte ont exhibé de la philopatrie et de la dispersion. Le recrutement local et l’immigration ont contribué au taux de croissance durant la période de référence. Le recrutement n’a pas compensé pour la perte de mâles adultes et a compensé partiellement pour la perte de femelles adultes durant la période de traitement. L’intervalle moyen des naissances est demeuré similaire (période de référence = 18.3 mo., 95% CI = 15.5–21.1; période de traitement = 19.4 mo., 95% CI = 16.2–22.6), alors que la taille des portées (période de référence = 2.8, 95% CI = 2.4–3.1; période de traitement = 2.4, 95% CI = 2.0–2.8) et le taux de parturition (période de référence = 0.63, 95% CI = 0.49–0.75; période de traitement = 0.48, 95% CI = 0.37–0.59) ont diminué légèrement durant la période de traitement. Les chasseurs de pumas qui ont eu du succès ont utilisé des chiens, ils sélectionnaient primairement les mâles et ont récolté des pumas à l’intérieur de 1–2 jours (médiane). Nous avons trouvé qu’un taux de récolte moyen avoisinant 22% du nombre estimé de pumas indépendants sur quatre ans et avec >20% de femelles adultes dans la récolte réduisait grandement l’abondance de puma. À cette échelle, le taux de mortalité annuel provenant de la chasse était en moyenne 6.3 fois plus grand que le taux provenant de tous les autres causes de mortalité humaine et 4.6 fois plus grand que le taux de mortalité de source naturelle durant la période de déclin de la population. La mortalité par la chasse était largement additive et la reproduction et le recrutement n’ont pas compensé pour cette source de mortalité. Nous avons trouvé que les chasseurs montraient une sélection pour les pumas mâles, entrainant alors une réduction de la survie et de l’abondance des mâles et impactant la structure des âges de la population. Nous recommandons qu’une chasse régulée dans une structure source‐puit peut être utilisée afin d’aider la conservation des pumas, procurer des opportunités de chasse durable, et adresser les conflits pumas‐humains.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Chapter
Conservation of mammals in the coniferous forests of western North America has shifted in recent years from species-based strategies to community- and ecosystem-based strategies, resulting in an increase in the available information on mammalian communities and their management. This book provides a synthesis of the published literature on the role of forest mammals in community structure and function, with emphasis on their management and conservation. In addition to coverage of some of the charismatic megafauna such as grizzly bears, gray wolves, mountain lions, elk and moose, the book also provides a thorough treatment of small terrestrial mammals, arboreal rodents, bats, medium-sized carnivores, and ungulates. The unique blend of theoretical and practical concepts makes this book equally suitable for managers, educators, and research biologists who will find it a valuable reference to the recent literature on a vast array of topics on mammalian ecology.
Article
Systematic pellet-group counts for big game trend, census, and distribution originated in the late 1930's and have since been used for a variety of research and management objectives. Their chief advantage is that pellet groups can be sampled by standard field plot techniques. Most pellet-group plots have been circles or long narrow rectangles, usually distributed in some form of stratified-random design. Sample plot layout can often be planned to minimize variance between plots or groups of plots. Sampling technique will depend upon local objectives, but some guidelines have been recognized. Sampling is generally more efficient in areas of higher pellet-group density. If pellet groups are distributed uniformly, a large area may require no more plots for adequate sampling than a small area. Pellet groups generally are deposited in a clumped pattern. Sampling intensity estimates can be made on the basis of the mean and variance derived from preliminary sample counts. Daily defecation rate is needed for computing deer-days use or total numbers of deer. Available data on defecation rate for wild native North American ruminants is tabulated, with some information on livestock and one exotic, the Barbary sheep. High defecation rate in deer has been observed to accompany high feed intake, high forage moisture content, high percentage of young in the herd, change in diet from roughage to concentrates, and the psychological impact of captivity. Observer bias arises mainly from differences in interpretation and from missed groups. Because of missed groups most counts will underestimate actual pellet-group density. Missed groups error is influenced by plot size and shape, type and density of understory vegetation, and observer fatigue and inherent visual acuity. Sources of interpretational differences include decisions concerning peripheral groups, scattered groups, and the minimum number of pellets to be counted as a group. Common practice requires use of permanently marked plots which are periodically cleared. Temporary plots are sometimes used where the deposition period can be dated by reference to leaf-fall, by deformation of pellets due to emergence of succulent feed, or by estimation of the period of herd occupancy of seasonal range. Such dating schemes introduce an additional source of observer bias. Pellet group counts have been unworkable at times because of rapid loss of pellets by insect attack or heavy rains, because of difficulties in identifying pellets of different species, or because of extremely dense vegetation. In a few cases the pellet group count has been tested against known numbers of deer in fenced areas, or against other census techniques. Reasonable accuracy of estimate has been obtained in many cases.
Mountain lion social organization in the Idaho Primitive Area Impacts of mountain lions on mule deer and cattle. Pages 17-32 in R. L. Phil-lips and C
  • Cougar Population
COUGAR POPULATION DYNAMICS o Lindzey et al. J. Wildl. Manage. 58(4):1994 SEIDENSTICKER, J. C., M. G. HORNOCKER, W. V. WILES, AND J. P. MESSICK. 1973. Mountain lion social organization in the Idaho Primitive Area. Wildl. Monogr. 35. 60pp. SHAW, H. G. 1977. Impacts of mountain lions on mule deer and cattle. Pages 17-32 in R. L. Phil-lips and C. J. Jonkel, eds. Proc. 1975 predator symposium. Mont. For. Conserv. Exp. Stn., School For., Univ. Montana, Missoula.
Land systems inventory on the Escalante Ranger District
  • R K Tew
TEW, R. K. 1972. Land systems inventory on the Escalante Ranger District, Dixie National Forest. U.S. For. Serv. Tech. Rep., Cedar City, Ut. 95pp.