Population Characteristics and Movement Patterns of Cougars in Southern Utah

Abstract

Twenty-two cougars (Felis concolor) were monitored by radiotelemetry between January 1979 and July 1981 in southern Utah. The population, comprised of resident, transient, and juvenile cougars, remained relatively constant during the study. Densities (0.3-0.5 cougars/100 km2) were considerably lower and home-area size of four resident females (685 km2, SE = 257, range = 396-1,454) and a single resident male (826 km2) were larger than reported for other areas. Home areas of resident females overlapped, but with the exception of family groups, close spatial associations were rare. Dispersal of male cubs appeared independent of resident adult density. Density of resident cougars was apparently regulated by a social pattern based on land tenure, but limited by the abundance of mule deer (Odocoileus hemionus), their principal prey. J. WILDL. MANAGE. 48(4):1275-1284 The elusive nature of the cougar, coupled with its common reputation as a destructive predator, has hampered field studies of this species. Work in Idaho by Hornocker (1969, 1970) and Seidensticker et al. (1973) indicated that an adult cougar population consisted of breeding residents and a variable number of transients that established residency and bred only when sites were provided by removal of residents. In addition, they concluded that social constraints maintained the population below a level set by prey densities. More recent information from Nevada (Ashman 1981), California (Sitton 1977; Koford 1978; Hopkins et al., in press), Arizona (Shaw 1977, 1979, 1982), Colorado (Currier et al. 1977), and British Columbia (Dewar and Dewar 1976) has demonstrated the behavioral variability of cougars. Although differences in density and home-area size might be expected under varying environmental conditions, differences in population composition and dispersion patterns are less easily explained. Although Shaw (1977), Sitton (1977), D. Ashman (pers. commun.), and Hopkins et al. (in press) found that resident males used overlapping areas, Hornocker (1969, 1970) and Seidensticker et al. (1973) did not observe adult males sharing areas. Similarly, female overlap was recorded in Idaho but not in California. In contrast to other investigators, Hopkins et al. (in press) reported more resident males than females and no transients in their study population of six adult cougars. The objective of our study was to investigate the movement patterns and population characteristics of an unhunted cougar population on a relatively isolated but heterogeneous study area in southcentral Utah. We are grateful to A. J. Button for his indispensable help as our houndsman and chief technician. W. Button helped in capture operations and provided a site for our winter camp. The Button and Coleman families, M. Reid, F. VanDyke, K. A. Johnson, D. Shepardson, K. Parr, M. H. Hemker, B. A. Blakesley, R. E. Gruenig, 'Funding was provided by Utah Div. of Wildl. Resour. and the study conducted under the auspices of the Utah Coop. Wildl. Res. Unit: Utah Div. of Wildl. Resour., Utah State Univ., U.S. Fish and Wildl. Serv., and Wildl. Manage. Inst. cooperating. 2 Present address: Idaho Department of Fish and Game, P.O. Box 4229, Pocatello, ID 83205. J. Wildl. Manage. 48(4):1984 1275 This content downloaded from 157.55.39.144 on Wed, 07 Sep 2016 05:49:04 UTC All use subject to http://about.jstor.org/terms 1276 SOUTHERN UTAH COUGAR POPULATION * Hemker et al. L. Cox, and R. D. Peters assisted with the fieldwork. F. H. Coles, J. G. Guyman, N. V. Hancock, F. C. Jensen, T. Gardiner, and T. Rettberg of the Utah Div. of Wildl. Resour. (UDWR) provided important support and advice. F. H. Coles, K. R. Dixon, and F. F. Knowlton gave valuable criticism of the manuscript. Cooperation was provided by the USDA For. Serv. and USDI Bur. of Land Manage. (BLM). The Utah State Ecol. Cent. provided support during the final stages of the study.