Incorporating behavior into habitat selection models

Patterns of resource selection by animal populations emerge as a result of hierarchical habitat selection by individuals. Statistical models that describe these population-level patterns of habitat use can miss important interactions between individual animals and characteristics of their home range; however, identifying these interactions is difficult. One approach to this challenge is to incorporate models of individual movement into habitat-use models. We studied the summer habitat use of 18 female elk (Cervus elaphus) in Yellowstone National Park and examined how habitat selection emerged from an interaction among individual-specific relocation kernels and landscape covariates. Elk typically selected for areas that provided a mixture of high-biomass grasslands and high-cover, young stands of coniferous forest. However, we also found that habitat selection was highly variable among individuals and changed as a function of time. It is important to account for this variability in models of habitat selection because the expectation of movement, and thus the landscape available to an animal at any given time, strongly depends on how time of day affects the baseline behavior of the individual (i.e. the shape of the relocation kernel). Our results indicate that a careful consideration of individual variability and time of day effects may help develop more robust models of habitat use.