Artelle et al. (2013)

Abstract: Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone – discrepancy between expected and realized mortality levels – led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.

Fox and Bekoff (2011)

Abstract: Few animals provoke as wide a range of emotions as wolves. Some see wolves as icons of a lost wilderness; others see them as intruders. As the battle continues between wolf proponents and opponents, finding solutions that resolve conflicts while supporting the integrity of nature is challenging. In this essay we argue that we need to make room for wolves and other native carnivores who are re-colonizing areas from which they were extirpated. Strategies that foster coexistence are necessary and wildlife agencies must consider all stakeholders and invest adequate resources to inform the public about how to mitigate conflicts between people/domestic animals, and predators. Values and ethics must be woven into wildlife policy and management and we must be willing to ask difficult ethical questions and learn from past mistakes.

Cooley at al. (2010)

Widespread mule deer (Odocoilus hemionous) declines coupled with white-tailed deer (O. virginianus) increases prompted us to investigate the role of cougar (Puma concolor) predation in a white-tailed deer, mule deer, and cougar community in northeast Washington, USA. We hypothesized that cougars select for and disproportionately prey on mule deer in such multiple-prey communities. We estimated relative annual and seasonal prey abundance (prey availability) and documented 60 cougar kills (prey usage) from 2002 to 2004. White-tailed deer and mule deer comprised 72% and 28% of the total large prey population and 60% and 40% of the total large prey killed, respectively. Cougars selected for mule deer on an annual basis (amd 1⁄4 0.63 vs. awt 1⁄4 0.37; P 1⁄4 0.066). We also detected strong seasonal selection for mule deer with cougars killing more mule deer in summer (amd 1⁄4 0.64) but not in winter (amd 1⁄4 0.53). Cougars showed no seasonal selection for white-tailed deer despite their higher relative abundance. The mean annual kill interval of 6.68 days between kills varied little by season (winter 1⁄4 7.0 days/kill, summer 1⁄4 6.6 days/kill; P 1⁄4 0.78) or prey species (white-tailed deer 1⁄4 7.0 days/kill, mule deer 1⁄4 6.1 days/kill; P 1⁄4 0.58). Kill locations for both prey species occurred at higher elevations during summer months (summer 1⁄4 1,090 m, winter 1⁄4 908 m; P 1⁄4 0.066). We suspect that cougars are primarily subsisting on abundant white-tailed deer during winter but following these deer to higher elevations as they migrate to their summer ranges, resulting in a greater spatial overlap between cougars and mule deer and disproportionate predation on mule deer.

Stoner et al. (2010)

Abstract: We used Global Positioning System technology to document distance, movement path, vegetation, and elevations used by a dispersing subadult female cougar (Puma concolor) through the fragmented habitat of the Intermountain West, USA. Over the course of 1 year, female number 31 moved 357 linear km, but an actual distance of 1,341 km from the Oquirrh Mountains, Utah to the White River Plateau, Colorado, constituting the farthest dispersal yet documented for a female cougar. This cougar successfully negotiated 4 major rivers and one interstate highway while traversing portions of 3 states. Our data suggest that transient survival, and therefore total distance moved, may be enhanced when dispersal occurs during the snow-free season due to low hunting pressure and greater access to high elevation habitats. Long- distance movements by both sexes will be required for the recolonization of vacant habitats, and thus inter-state management may be warranted where state boundaries do not coincide with effective dispersal barriers.

Robinson et al. (2008)

Abstract: Carnivores are widely hunted for both sport and population control, especially where they conflict with human interests. It is widely believed that sport hunting is effective in reducing carnivore populations and related human–carnivore conflicts, while maintaining viable populations. However, the way in which carnivore populations respond to harvest can vary greatly depending on their social structure, reproductive strategies, and dispersal patterns. For example, hunted cougar (Puma concolor) populations have shown a great degree of resiliency. Although hunting cougars on a broad geographic scale (.2000 km2) has reduced densities, hunting of smaller areas (i.e., game management units, ,1000 km2), could conceivably fail because of increased immigration from adjacent source areas. We monitored a heavily hunted population from 2001 to 2006 to test for the effects of hunting at a small scale (,1000 km2) and to gauge whether population control was achieved...

Proceedings of the 9th Mountain Lion Workshop, Sun Valley, ID
May 5 - 8, 2008

Stoner et al. (2006)

Abstract: Currently, 11 western states and 2 Canadian provinces use sport hunting as the primary mechanism for managing cougar (Puma concolor) populations. Yet the impacts of sustained harvest on cougar population dynamics and demographic structure are not well understood. We evaluated the effects of hunting on cougar populations by comparing the dynamics and demographic composition of 2 populations exposed to different levels of harvest. We monitored the cougar populations on Monroe Mountain in south-central Utah, USA, and in the Oquirrh Mountains of north-central Utah from 1996 to 2004. Over this interval the Monroe population was subjected to annual removals ranging from 17.6–51.5% (mean 6 SE 1⁄4 35.4 6 4.3%) of the population, resulting in a .60% decline in cougar population density. Concurrently, the Oquirrh study area was closed to hunting and the population remained stationary. Mean age in the hunted population was lower than in the protected population (F 1⁄4 9.0; df 1⁄4 1, 60.3; P 1⁄4 0.004), and in a pooled sample of all study animals, females were older than males (F 1⁄4 13.8; df 1⁄4 1, 60.3; P , 0.001). Females from the hunted population were significantly younger than those from the protected population (3.7 vs. 5.9 yr), whereas male ages did not differ between sites (3.1 vs. 3.4 yr), suggesting that male spatial requirements may put a lower limit on the area necessary to protect a subpopulation. Survival tracked trends in density on both sites. Levels of human-caused mortality were significantly different between sites (v2 1⁄4 7.5; P 1⁄4 0.006). Fecundity rates were highly variable in the protected population but appeared to track density trends with a 1-year lag on the hunted site. Results indicate that harvest exceeding 40% of the population, sustained for...

Choate et al. (2006)

Abstract: Numerous techniques have been proposed to estimate or index cougar (Puma concolor) populations, but few have been applied simultaneously to populations with reliable estimates of population size. Between 1996 and 2003, we evaluated the relative efficacy and accuracy of multiple estimation and index techniques for populations at 2 locations in Utah, USA: Monroe Mountain and the Oquirrh Mountains. We used radiotagging followed by intensive monitoring and repeated capture efforts to approach a complete enumeration of the populations. We used these benchmarks to evaluate other population estimates (Lincoln–Petersen mark–recapture, helicopter-survey probability sampling, catch-per- unit-effort) and indices (scent-station visits, track counts, hunter harvest). Monitoring over 600 scent-station-nights using different attractants June–September in 1996 and 1997 yielded a single cougar visit. Summer track-based indices reflected a 54–69% reduction in population size on the Monroe site and a numerically stable population on the Oquirrhs, but relationships between indices and the benchmark population estimates varied among techniques. Aerial track surveys required sufficient fresh snowfall accumulations for adequate tracking coverage of a given unit, conditions that were met only once on one study site in each of 3 years. Population estimates derived from helicopter-survey probability sampling exceeded reference population estimates by 120–284%, and bootstrapped estimates of standard error encompassed 25– 55% of the population estimates (e.g., 5.6 6 1.4 cougars/100 km2). Despite poor performance in predicting cougar population sizes, track- based estimates may provide better indices for monitoring large changes in population trends (i.e., with low precision). However, we recommend using multiple indices after determination of a more rigorous initial population estimate for managing populations of conservation concern and when considering connectivity to determine potential refuge sites for regional management (e.g., management by zones).
This research funded in part through a grant from the Cougar Fund

Lambert et al. (2006)

Abstract: Increasing reports of human/cougar conflicts may suggest that cougars are increasing in the Pacific Northwest. We determined minimum relative densities and average fecundity, survival, and growth rate of an apparently increasing cougar population in northeastern Washington, USA; northern Idaho, USA; and southern British Columbia, Canada, from 1998 to 2003. Minimum relative densities declined from 1.47 cougars/ 100 km2 to 0.85 cougars/100 km2. We estimated average litter size at 2.53 kittens, interbirth interval at 18 months, proportion of reproductively successful females at 75%, and age at first parturition at 18 months for a maternity rate of 1.27 kittens/adult female/yr. Average survival rate for all radiocollared cougars was 59%: 77% for adult females, 33% for adult males, 34% for yearlings, and 57% for kittens. Hunting accounted for 92% of mortalities of radiocollared cougars. The annual stochastic growth rate of this population was k 1⁄4 0.80 (95% CI 1⁄4 0.11). Contrary to accepted belief, our findings suggest that cougars in the Pacific Northwest are currently declining. Increased conflicts between cougars and humans in this area could be the result of the 1) very young age structure of the population caused by heavy hunting, 2) increased human intrusion into cougar habitat, 3) low level of social acceptance of cougars in the area, or 4) habituation of cougars to humans. To help preserve this population, we recommend reduced levels of exploitation, particularly for adult females, continuous monitoring, and collaborative efforts of managers from adjacent states and provinces.