Habitats drive population biology

点击翻译按钮获取中文摘要

Early in my career I focused on demographic models in stochastic and seasonal environments, but it became clear that such theoretical constructs were insufficient for conservation applications. Links with habitats are essential for useful applications of population models, and in my lab we have developed many quantitative tools for building connections between habitats and populations. Animals are more abundant in habitats that are selected most strongly and, for the species that we have studied, fitness is highest in these habitats. Models of habitat selection can be used to distribute animals on the landscape and when the population is at carrying capacity, resource selection functions (RSF) can be used to estimate abundance. If the population is not at equilibrium, abundance might be influenced by factors not directly related to habitats thereby potentially (but not necessarily) compromising the use of habitat selection models for predicting population size. Distribution among habitats often is density dependent, but seldom follows an ideal free distribution. Many other complications can occur such as seasonal use of habitats, but such seasonality can be accommodated in model structure. Field studies to apply the principles of habitat-based population models will focus on my continuing studies of elk, grizzly bears, and wolverines. Our long-term elk studies are grounded in one of the largest radiotelemetry studies ever conducted on this species with substantially over 1 million GPS relocations accumulated during the past 8 years on seasonal ranges in SW Alberta. We have developed methods for step-selection functions (SSF) that allow us to analyze patterns of movement in context of habitats. Collaborators from Europe have shared comparable data on red deer revealing similar patterns of habitat selection and demography. Our proposed grizzly bear and black bear studies likewise extend habitat selection based on radiotelemetry data and more recently population inferences based on DNA from hair samples collected at rub trees. We are proposing to develop methods for Spatially Explicit Capture Recapture (SECR) population estimation and monitoring for bears. The structure of bear populations in SW Alberta suggests a source-sink balance with sinks often driven by conflicts with agriculture. Finally, we are excited about our ability to study wolverines in boreal and montane regions of Alberta using radiotelemetry and noninvasive sampling. Modern technology has allowed us to assemble new findings about habitat selection and demography of wolverines in the boreal forests of NW Alberta. This archetypical wilderness species coexists with humans in an industrial landscape at densities much higher than previously documented. Again, tools of SECR, RSF, and SSFs allow us to marry habitat ecology with population ecology in novel ways with applications for conservation biology and management.