Frederick G. Lindzey

Estimating cougar predation rates from GPS location clusters

We examined cougar (Puma concolor) predation from Global Positioning System (GPS) location clusters (≥2 locations within 200 m on the same or consecutive nights) of 11 cougars during September-May, 1999-2001. Location success of GPS averaged 2.4-5.0 of 6 location attempts/night/cougar. We surveyed potential predation sites during summer-fall 2000 and summer 2001 to identify prey composition (n = 74; 3-388 days post predation) and record predation-site variables (n = 97; 3-270 days post predation). We developed a model to estimate probability that a cougar killed a large mammal from data collected at GPS location clusters where the probability of predation increased with number of nights (defined as locations at 2200, 0200, or 0500 hr) of cougar presence within a 200-m radius (P< 0.001). Mean estimated cougar predation rates for large mammals were 7.3 days/kill for subadult females (1-2.5 yr; n = 3, 90% CI: 6.3 to 9.9), 7.0 days/kill for adult females (n = 2, 90% CI: 5.8 to 10.8), 5.4 days/kill for family groups (females with young; n = 3, 90% CI: 4.5 to 8.4), 9.5 days/kill for a subadult male (1-2.5 yr; n = 1, 90% CI: 6.9 to 16.4), and 7.8 days/kill for adult males ( n = 2, 90% CI: 6.8 to 10.7). We may have slightly overestimated cougar predation rates due to our inability to separate scavenging from predation. We detected 45 deer (Odocoileus spp.), 15 elk (Cervus elaphus), 6 pronghorn (Antilocapra americana), 2 livestock, I moose (Alces alces), and 6 small mammals at cougar predation sites. Comparisons between cougar sexes suggested that females selected mule deer and males selected elk (P < 0.001). Cougars averaged 3.0 nights on pronghorn carcasses, 3.4 nights on deer carasses, and 6.0 nights on elk carcasses. Most cougar predation (81.7%) occurred between 1901-0500 hr and peaked from 2201-0200 hr (31.7%). Applying GPS technology to identify predation rates and prey selection will allow managers to efficiently estimate the ability of an areas prey base to sustain or be affected by cougar predation.

Home Range and Habitat Use by Black Bears in Southwestern Washington

Movement and activity of 16 black bears (Ursus americanus) of a population of 23 were monitored by radio telemetry between March 1973 and October 1975 on an island in southwestern Washington. Average home-range sizes of adult males (505 ha) and females (235 ha) were markedly smaller than home-range estimated for bears in other parts of the United States. Richness of habitat on the island presumably allowed smaller home ranges. Home ranges of sex and age groups overlapped, with use of shared areas apparently determined by a social hierarchy. Males varied more than females in seasonal use of their home ranges. Bears used certain vegetation types on the island disproportionately to their availability, apparently selecting for areas logged since 1963 and against areas logged before 1935. J. WILDL. MANAGE. 41(3):413-425 Historically, management of the black bear has relied principally on the gun. Before studies by Stickley (1957), Black (1958), Erickson et al. (1964), and Jonkel and Cowan (1971), biological data for this species that could be used in management planning were essentially nonexistent. Data from these studies, however, are often limited in their application because of regional differences. In the Pacific Northwest where clearcutting, the dominant timber harvesting technique, dramatically alters the vegetative composition of thousands of hectares each year, and demands of both sportsmen and timber industry influence black bear management policies, the need for biological data concerning the black bear is obvious. Before a study by Poelker and Hartwell (1973), to which the late D. Pierson made significant contributions, game agencies in Oregon and Washington used biological information from other regions. Emphasis of that study, however, was directed at investigating the reasons black bears damaged

Mule deer and pronghorn migration in western Wyoming

Abstract Migratory mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana) populations rely on seasonal ranges to meet their annual nutritional and energetic requirements. Because seasonal ranges often occur great distances apart and across a mix of vegetation types and land ownership, maintaining migration corridors to and from these ranges can be difficult, especially if managers do not have detailed information on mule deer and pronghorn seasonal movements. We captured, radiomarked, and monitored mule deer (n=171) and pronghorn (n=34) in western Wyoming to document seasonal distribution patterns and migration routes. Mule deer and pronghorn migrated 20–158 km and 116–258 km, respectively, between seasonal ranges. These distances represented the longest recorded migrations for either species. We identified a number of bottlenecks along the migration routes of mule deer and pronghorn, but the most critical appeared to be the 1.6-km-wide Trappers Point bottleneck, which was used by both mule deer and pronghorn during their spring and autumn migrations. Housing developments and roadways apparently have reduced the effective width of this bottleneck to <0.8 km. We estimate 2,500–3,500 mule deer and 1,500–2,000 pronghorn move through the bottleneck twice a year during spring and autumn migrations. Identification and protection of migration corridors and bottlenecks will be necessary to maintain mule deer and pronghorn populations throughout their range.

Cougar Population Dynamics in Southern Utah

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 cougars 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

Experimental evaluation of population trend and harvest composition in a Wyoming cougar population

Abstract Cougar (Puma concolor) management has been hindered by inability to identify population trends. We documented changes in sex and age of harvested cougars during an experimentally induced reduction in population size and subsequent recovery to better understand the relationship between sex–age composition and population trend in exploited populations. The cougar population in the Snowy Range, southeast Wyoming, was reduced by increased harvest (treatment phase) from 58 independent cougars (>1 year old) (90% CI=36–81) in the autumn of 1998 to 20 by the spring of 2000 (mean exploitation rate=43%) and then increased to 46 by spring 2003 following 3 years of reduced harvests (mean exploitation rate=18%). Pretreatment harvest composition was 63% subadults (1.0–2.5 years old), 23% adult males, and 14% adult females (2 seasons; n=22). A reduction in subadult harvest, an initial increase followed by a reduction in adult male harvest, and a steady increase in adult female harvest characterized harvest composition trends during the treatment phase. Harvest composition was similar at high and low densities when harvest was light, but proportion of harvested subadult males increased at low density as they replaced adult males removed during the treatment period (high harvest). While sex ratio of harvested cougars alone appears of limited value in identifying population change, when combined with age class the 2 appear to provide an index to population change. Composition of the harvest can be applied to adaptively manage cougar populations where adequate sex and age data are collected from harvested animals.

Development and evaluation of sightability models for summer elk surveys

We developed 2 sightability models from summer helicopter surveys of radiocollared elk (Cervus elaphus) in Grand Teton National Park, Wyoming. Significant variables (P 30% vegetation cover), but this overestimation was ac- counted for by Model B. Thus, we recommend application of the Idaho model during summer surveys where elk are less gregarious (<20 elk) and recommend application of summer Model B to high-density elk popu-

Population Characteristics of Black Bears on an Island in Washington

Twenty-three black bears (Ursus americanus) were captured on an island in southwestern Washington. Age structure of the population indicated that it was young and growing, and that breeding was relatively synchronized. Density of bears over a year of age (1 bear per 89-67 ha) on the island was high in comparison to estimates of density elsewhere in North America. J. WILDL. MANAGE. 41(3):408-472 Black bear densities vary over their range in North America. Locally, densities may be influenced by habitat quality (Jonkel and Cowan 1971, Lindzey and Meslow 1977) and hunting (McIlroy 1972:837, Wakefield 1972:51). Behavior patterns may be the proximal determinant of densities; the role of behavior often may not be apparent, however, because of low population numbers. Behavior that determines dispersion patterns is presumably not independent of the influence of habitat, but flexible (behavioral scaling, Wilson 1975:19) in response to quality of particular habitats. Jonkel and Cowan (1971:35) observed female cubs that established permanent residency in their mothers home range; such behavior would presumably be disadvantageous to the adult female if resources were scarce. The extension of family relationships as observed by Jonkel and Cowan (1971:38) may influence not only densities but sex and age composition of local populations as well. These population attributes through behavioral scaling thus may reflect habitat quality. Hunting may interfere with the establishment of associations that would provide these patterns in a population. This paper reports on the demographic characteristics of a lightly-hunted population of 23 black bears on an island in southwestern Washington. Dispersion of members of this population suggested tolerance among related individuals (Lindzey and Meslow 1977). J. M. Welch, refuge manager, Willapa National Wildlife Refuge, H. Hardesty, and R. Van Wormer provided logistic support during the study. S. D. Lindzey, R. Walker, R. Libby, A. K. Miles, and W. Welch assisted with field work. The late H. M. Wight provided encouragement and advice. H. C. Black, J. A. Crawford, D. S. deCalesta, and C. J. Jonkel gave valuable criticisms of the manuscript. The Weyerhaeuser Company and Washington Department of Game granted permits necessary to conduct the study.

Winter Dormancy in Black Bears in Southwestern Washington

Despite relatively mild weather, black bears (Ursus americanus) in southwestern Washington entered dens and remained for an average of 126 days. Bears entered their dens during a 5-week period that began on 21 October. A significant difference (P < 0.05) was found among the average dates of den entrance of adult females, yearlings, and adult males. Adult females were the first bears to enter their dens; yearlings entered next, and adult males entered last. The stimulus to enter a den probably was provided by the cumulative effect of weather. The actual period of winter dormancy was preceded and followed by periods of increased inactivity. Inactivity during the predenning and postdenning periods was correlated with daily weather, principally maximum daily temperature and precipitation. J. WILDL. MANAGE. 40(3):408-415 Through most of their range, black bears enter dens and remain inactive during winter months; this trait apparently allows them to occupy areas where scarce winter food supplies might otherwise preclude their presence. The timing of entrance into the den and emergence from the den in the spring may be influenced by weather (Northcott and Elsey 1971) or physical condition (Spencer 1955). Erickson (1964) and Jonkel and Cowan (1971) presented data that suggest the timing of these events may differ among the various sex and age groups in a population. Because the black bear is managed almost entirely by hunter-oriented programs, a knowledge of the timing of winter dormancy is important. Also, because estimates of population parameters of the black bear frequently are derived from hunter-killed samples (Willey 1971, P-R Job Prog. Rep., Proj. W-38-R, Vermont Fish Game Dept., Montpelier, Mcllroy 1972), the knowledge of possible sources of bias such as disproportionate availability, which might be caused by differential entry and eme gence dates of the various sex and age groupings, is desirable. Published accounts of winter dormancy in the black bear, with few exceptions, have come from regions of their range characteriz d by climatically severe winters. Poelker and Hartwell (1973) presented the first documented accounts of winter dormancy of the black bear in southwestern Washington, an area of mild winters. They concluded, after following the movements of a subadult female, that the period of winter dormancy was nearly 3 months. The bear, however, had been aroused from dens on n ne occasions, which may have biased the accurate appraisal of both the intensity and duration of winter dormancy. Our objective is to report on the temporal aspect of winter do mancy and associated periods of inactivity of 13 black bears. S. D. Lindzey, R. E. Walker, A. K. Miles, and R. Libby assisted with field work. The Weyerhaeuser Company and Washington Department of Game provided permits necessary to conduct this study. J. M. Welch, Manager, Willapa National Wildlife Refuge, and H. Hardesty provided logistical support during the term of the study. H. C. Black, J. A. Crawford, and A. W. Erickson offered valuable criticism of the manuscript. The late H. M. Wight, Leader, Oregon Coopera1 Study conducted and supported under the auspices of the Oregon Cooperative Wildlife Research Unit: Oregon Department of Fish and Wildlife, Oregon State University, U.S. Fish and Wildlife Service, and The Wildlife Management Institute cooperating. Oregon State University Agricultural Experiment Station Technical Paper No. 4123. 408 J. Wildl. Manage. 40 (3):1976 This content downloaded from 157.55.39.17 on Wed, 31 Aug 2016 04:28:01 UTC All use subject to http://about.jstor.org/terms WINTER DORMANCY IN BLACK BEARS * Lindzey and Meslow 409 tive Wildlife Research Unit, provided stimulus and direction to our efforts.

Brood Habitats of Sympatric Sage Grouse and Columbian Sharp-Tailed Grouse in Wyoming

Habitats used by sympatric sage grouse (Centrocercus urophasianus) and Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus) were compared. Sage grouse broods occurred most often (68%) in sagebrush (Artemisia spp.)-grass and sagebrush-bitterbrush (Purshia tridentata) habitats, whereas sharp-tailed grouse broods occurred most often (73%) in mountain shrub and sagebrush-snowberry (Symphoricarpos oreophilus) habitats. Mountain shrub and sagebrush-snowberry habitats were used by sharptailed grouse more (P < 0.05) than expected based on their availability. Broods of both species used areas within each habitat with less shrub cover than average for that habitat. Sharp-tailed grouse broods were associated with mountain snowberry, oniongrass (Melica spp.), and sulphur buckwheat (Eriogonum umbellatum). Sites used by sage grouse contained needle-and-thread (Stipa comata) and desert alyssum (Alyssum desertorum). J. WILDL. MANAGE. 54(1):84-88 Distribution of sage grouse and Columbian sharp-tailed grouse historically overlapped in 8 western states (Aldrich 1963). The geographic range of both species has been reduced, and Columbian sharp-tailed grouse currently occupy <10% of their former range (Miller and Graul 1980). Presently, Columbian sharp-tailed grouse occur only in Idaho, Wyoming, Utah, Colorado, Montana, Washington, and British Columbia (Miller and Graul 1980). Although habitat use patterns have been documented for sage grouse (Dalke et al. 1963, Klebenow 1969, Rothenmaier 1979) and sharp-tailed grouse (Rogers 1969, Oedekoven 1985, Marks and Marks 1987) independently, habitat use has not been investigated for the 2 species when they occur sympatrically. Both species occupy shrub-steppe communities (Dalke et al. 1963, Marks and Marks 1987) dominated by sagebrush and other shrubs including rabbitbrush (Chrysothamnus spp.), antelope bitterbrush, and common chokecherry (Prunus virginiana). The objectives of our study were to document vegetation types used by sage and sharp-tailed grouse broods and to examine whether sites used by the 2 species differed structurally or vegetatively. Funding was provided by the Rawlins District of the Bureau of Land Management. We gratefully acknowledge L. J. Saslaw and J. R. Farrell of the Bureau of Land Management and D. L. Moody of the Wyoming Game and Fish Department for assistance in locating grouse leks. S. P. Gallagher and A. L. Vail-Klott assisted with vegetation sampling and locating grouse broods. We thank W. R. Eddleman for comments on early drafts of the manuscript. This study was conducted under the auspices of the Wyoming Cooperative Fishery and Wildlife Research Unit, U.S. Fish and Wildlife Service, University of Wyoming, Wyoming Game and Fish Department, and Wildlife Management Institute cooperating.

Survival Rates of Mountain Lions in Southern Utah

We monitored survival of resident mountain lions (Felis concolor) during a radio-telemetry study between 1980 and 1986 in southern Utah. Yearly survival of resident adults ranged from 52 to 100% (9 = 74%). Causes of death included intraspecific killing, injury related to prey capture, trapping, and starvation. Deaths of dispersing offspring were human-related. J. WILDL. MANAGE. 52(4):664-667 Mountain lions were first protected as game animals in the 1960s (Nowak 1976). Since that time, most states and provinces with viable mountain lion populations have assumed authority for their management. Management efforts have been hindered by a lack of data on the dynamics of mountain lion populations. Annual mortality rates were estimated by Robinette et al. (1977:123) at 32% based on the age distribution of harvested mountain lions. Ashman et al. (1983) reported similar mortality rates from the percent of marked animals harvested. Tanner (1975) reported an annual survival rate for mountain lions 1-13 years old of 88%, which he calculated from the literature (principally Hornocker 1970), and a highest survival rate of 95%, which he felt was possible in an optimum environment. Sport hunting is the major humanrelated cause of death for mountain lions. Other causes of death include predator control programs, injuries suffered during attempts to capture prey (Gashwiler and Robinette 1957, Hornocker 1970), intraspecific killing (Robinette et al. 1961, Hemker et al. 1984) and starvation (H. G. Shaw, Ariz. Game and Fish Dep., pers. commun.). Survival rates are commonly used in management programs but are difficult to estimate for long-lived, secretive mammals occurring at low densities. Inadequate or biased samples and failure to meet necessary assumptions often preclude use of techniques traditionally used to estimate survival rate, such as life table analysis (Caughley 1977:85-106). We analyzed longterm telemetry records and estimated survival rates for resident mountain lions using 2 techniques: MICROMORT (Heisey and Fuller 1985) and product-limit (Kurzejeski et al. 1987). We appreciate suggestions on analyses provided by G. C. White and D. R. Anderson and the field assistance of A. J. Button, W. W. Button, J. Roberson, T. D. Becker, F. G. Van Dyke, V. Judkins, C. H. Greenwood, and C. S. Mecham. Funding for this project was provided by the Utah Division of Wildlife Resources. The project was conducted under auspices of the Utah and Wyoming Cooperative Fishery and Wildlife research units.