Aerial surveys are the only practical way to estimate ungulate numbers in most of North America (LeResche and Rausch 1974, Timmerman 1974, Gassaway and Dubois 1987). These surveys, however, often provide biased estimates and only under specific…
Predator-prey models have traditionally been built on the assumption that neither predators nor prey are capable of learning or adapting behavior based on past interactions. As such, these models typically account for predation by forcing prey to…
Point count surveys of birds are commonly used to provide indices of abundance or, in some cases, estimates of true abundance. The most common use of point counts is to provide an index of population abundance or relative abundance. To make spatial…
Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus) populations have declined across their range and now occupy <10% of their historic range. Habitat loss, degradation, and fragmentation are key factors contributing to their range…
The management and research of mule deer (Odocoileus hemionus) in Colorado and throughout the Rocky Mountain West is an exciting arena for wildlife professionals as the prevailing view among biologists, managers, researchers, hunters, wildlife…
Like many wildlife species, the greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) has experienced extensive habitat loss and regional population declines as a result of agriculture, mining practices, and human settlement. Some…
Animals endemic to alpine habitats have been receiving increasing attention in recent years due to concerns over sensitivities of high elevation systems to climate warming. Long-term datasets are needed to assess trends in populations of alpine…
Understanding factors regulating populations is a fundamental goal of population ecology. Life-history traits such as survival and fecundity are key vital rates responsible for population change and may vary across elevational gradients. At the upper…