Abstract:
Resource selection function (RSF) models are commonly used to quantify species/ habitat
associations and predict species occurrence on the landscape. However, these models are
sensitive to changes in resource availability and can result in a functional response to resource
abundance, where preferences change as a function of availability. For generalist species, which
utilize a wide range of habitats and resources, quantifying habitat selection is particularly
challenging. Spatial and temporal changes in resource abundance can result in changes in
selection preference affecting the robustness of habitat selection models. We examined selection
preference across a wide range of ecological conditions for a generalist mega-herbivore, the
African savannah elephant (Loxodonta africana), to quantify general patterns in selection and to
illustrate the importance of functional responses in elephant habitat selection. We found a
functional response in habitat selection across both space and time for tree cover, with tree cover
being unimportant to habitat selection in the mesic, eastern populations during the wet season. A
temporal functional response for water was also evident, with greater variability in selection
during the wet season. Selection for low slopes, high tree cover, and far distance from people
was consistent across populations; however, variability in selection coefficients changed as a
function of the abundance of a given resource within the home range. This variability of
selection coefficients could be used to improve confidence estimations for inferences drawn from
habitat selection models. Quantifying functional responses in habitat selection is one way to
better predict how wildlife will respond to an ever-changing environment, and they provide
promising insights into the habitat selection of generalist species.
