US-IALE 2018

AUTHORS: Laura E. D’Acunto, Karly A. Rushmore*, Patrick A. Zollner – Purdue University; Benjamin Pauli, St. Mary’s University of Minnesota

ABSTRACT: Species-specific responses to landscape modification are dependent on where a species falls on the habitat specialist-generalist continuum. Some species are designated as specialists or generalists without sufficient evidence, which can then provide faulty predictions of a species’ response to fragmentation. In North America, population declines of bats have triggered a need to understand the habitat associations of species of concern. We compared an established landscape-scale hierarchical occupancy model built within a contiguous forest landscape for three bat species (the northern long-eared bat, Myotis septentrionalis, the Indiana bat, Myotis sodalis, and the little brown bat, Myotis lucifugus). These species fell along the specialist-generalist continuum (in regards to forest needs) in a previous model constructed with data from a human-modified landscapes. We hypothesized that species considered contiguous forest specialists would show more plasticity in habitats selected for than more generalist species. We used single-species hierarchical Bayesian occupancy modeling with and without informative priors, and multi-species occupancy models, to test this hypothesis. Our study provided several important insights for bat research and occupancy modeling in general. We found that multi-species models may perform better than single-species models in the case of declining species and that the use of informative priors for a declining species can reduce model fit and influence the outcome of model predictions. We demonstrated that forest-specialist northern long-eared bat and the slightly less forest-specialized Indiana bat exhibited plasticity of habitat selection in human-modified landscapes compared to a contiguous forest landscape. This plasticity could be due to an inherent ability of these species to utilize modified landscapes or a competitive release phenomenon from severe population declines due to disease.