Proceedings of the fifth mountain lion workshop: 27
Proceedings of the fifth mountain lion workshop: 27
Proceedings of the fifth mountain lion workshop: 27
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94 PROCEEDINGS OF THE FIFTH MOUNTAIN LION WORKSHOP<br />
TEN YEARS OF CALIFORNIA MOUNTAIN LION TRACK SURVEY<br />
K. Shawn Smallwood. Institute for Sustainable Development, Thoreau Center for Sustainability–The Presidio, P.O. Box<br />
29075, San Francisco, CA 94129-0075.<br />
Bruce Wilcox. Institute for Sustainable Development, Thoreau Center for Sustainability–The Presidio, P.O. Box 29075, San<br />
Francisco, CA 94129-0075.<br />
During <strong>the</strong> summer <strong>of</strong> 1995 we conducted <strong>the</strong> fourth statewide <strong>mountain</strong> <strong>lion</strong> track survey since 1985. Surveys<br />
were conducted in 1985 and 1986 by wildlife biologists from multiple natural resources agencies, mostly from <strong>the</strong> California<br />
Department <strong>of</strong> Fish and Game. Smallwood surveyed <strong>the</strong> transects in 1986, 1992, and 1995. Assuming <strong>the</strong> number <strong>of</strong> track<br />
sets is indicative <strong>of</strong> <strong>the</strong> <strong>mountain</strong> <strong>lion</strong> population, <strong>mountain</strong> <strong>lion</strong>s in California decreased in number substantially from <strong>the</strong><br />
mid 1980's to <strong>the</strong> 1990's. Regional trends have been dramatic, including alarming declines east <strong>of</strong> <strong>the</strong> Sierra Nevada and in<br />
sou<strong>the</strong>rn California. Declines in 1992 were followed by an increase across <strong>the</strong> northwest part <strong>of</strong> <strong>the</strong> state, <strong>the</strong> central coast,<br />
and <strong>the</strong> Sierra Nevada. The track sets found were clustered within small geographic areas; no tracks were found across <strong>the</strong><br />
vast majority <strong>of</strong> <strong>the</strong> <strong>mountain</strong> <strong>lion</strong> range that was sampled during 1992 and 1995. The clusters <strong>of</strong> track sets changed<br />
locations between surveys since <strong>the</strong> 1980's. Mountain <strong>lion</strong>s traveled along certain aspects <strong>of</strong> <strong>the</strong> dirt roads in directions and<br />
at locations according to habitat, topographic, and interspecific (prey and competitors) conditions. The <strong>mountain</strong> <strong>lion</strong><br />
population can be efficiently monitored across large areas, and it can serve as an indicator <strong>of</strong> large-scale ecological<br />
conditions by fur<strong>the</strong>r developing track count methodology.<br />
DISPERSAL OF COUGARS (Puma concolor)<br />
IN METAPOPULATION DYNAMICS<br />
Linda L. Sweanor. Hornocker Wildlife Institute Field Station, 7315 Aloe Court, Las Cruces, NM 88012 USA<br />
K.A. Logan. Hornocker Wildlife Institute Field Station, 7315 Aloe Court, Las Cruces, NM 88012 USA<br />
M.G. Hornocker. Hornocker Wildlife Institute, P.O. Box 3246, University Station, Moscow, ID 83843 USA<br />
We intensively studied an unhunted cougar population on <strong>the</strong> San Andres Mountains (SAM, 2060 km 2 )<br />
in sou<strong>the</strong>rn New Mexico from 1985-1995. We examined <strong>the</strong> role <strong>of</strong> dispersal in order to (1) adequately describe cougar<br />
population dynamics and social organization in <strong>the</strong> SAM, and (2) determine <strong>the</strong> importance <strong>of</strong> dispersers to o<strong>the</strong>r<br />
subpopulations within dispersal distance <strong>of</strong> <strong>the</strong> SAM. Characteristics <strong>of</strong> dispersing cougars, including age, sex and direction<br />
and distance traveled were based on 33 radiocollared progeny (20 F, 13 M) and 1 eartagged male born between June 1986<br />
and September 1992. Known age <strong>of</strong> independence for 12 <strong>of</strong> <strong>the</strong>se progeny averaged 13.5 months for females (n=6, SD=1.6)<br />
and 14.0 months for males (n=6, SD=1.5). Known age at dispersal for 8 progeny averaged 13.6 months for females<br />
(n=2,SD=0.9) and 15.7 months for males (n=6, SD=1.4). Twelve <strong>of</strong> 20 (60%) female progeny did not disperse from <strong>the</strong>ir<br />
natal areas, whereas all 14 <strong>of</strong> <strong>the</strong> male progeny dispersed. One <strong>of</strong> 20 females and 6-7 <strong>of</strong> 14 males dispersed outside <strong>the</strong><br />
SAM. Distances traveled by progeny from <strong>the</strong> arithmetic center <strong>of</strong> <strong>the</strong>ir natal home range (NAC) to <strong>the</strong> arithmetic center <strong>of</strong><br />
<strong>the</strong>ir independent home range (IAC) averaged 12.4 km for females (n=19, SD=19.6) and 101.3 km for males (n=7,<br />
SD=26.0). Dispersing males traveled by significantly fur<strong>the</strong>r from <strong>the</strong>ir NACs to <strong>the</strong>ir IACs than dispersing females (t=2.86,<br />
df=13, P=0.007). Dispersal directions from NACs to IACs were uniformly distributed about a 360E circle for both females<br />
(n=7, U 2 =0.08, P=0.48) and males (n=8, U 2 =0.06, P>0.05),. Recruitment and emigration rates were quantified based on a<br />
5.1 year time span (February 1990 to 23 February 1995) and 114 tagged progeny (63 F, 51 M) out <strong>of</strong> 137 detected progeny<br />
born from 1 February 1988 through 19 November 1992. From 1990-1995, 21 progeny (17 F, 4 M; x¯=4.1/year) and 22<br />
immigrants (8 F:14 M; x¯=4.3/year) were recruited into <strong>the</strong> adult SAM population. For <strong>the</strong> same period, we estimated that 47<br />
progeny (26 F, 21 M, x¯=9.2/year) successfully dispersed (i.e. dispersed and reached adulthood) outside <strong>the</strong> SAM. The<br />
majority <strong>of</strong> female (60%) and male (81%) cubs which are born on <strong>the</strong> SAM and survive to adulthood apparently disperse<br />
outside <strong>of</strong> <strong>the</strong> SAM. The SAM cougar population is an important source <strong>of</strong> immigrants to o<strong>the</strong>r cougar populations within<br />
dispersal distance <strong>of</strong> <strong>the</strong> SAM. The role <strong>of</strong> dispersal is important to <strong>the</strong> understanding <strong>of</strong> cougar metapopulation dynamics<br />
and <strong>the</strong> implementation <strong>of</strong> regional conservation strategies.