Context matters: Intrinsic and extrinsic factors modulate habitat choices in an endangered forest bat

Effective management of declining species depends upon fundamental understanding of habitat preferences during key life stages such as reproduction. Peripheral populations of wildlife are often poorly understood and rarely the focus of study, despite their contribution to genetic diversity and their potential to aid in recolonization if a species becomes endangered. We assessed the maternal roost-site preferences of the endangered northern long-eared bat (Myotis septentrionalis) within a managed forest near the western edge of their range in the Black Hills region of Wyoming, USA. We further examined whether habitat preferences and roost-switching varied by reproductive state (pregnant or lactating) or proximate weather conditions. Bats were more likely to roost in quaking aspens during pregnancy, and when weather was cooler and wetter. Conversely, bats roosted more in ponderosa pines (Pinus ponderosa) post-parturition, and when temperatures were warmer. Bats also were more likely to switch to a new roost after periods of warmer temperature and reduced solar radiation. Our results support growing evidence that habitat choices can be modulated proximately by intrinsic and extrinsic factors. Northern long-eared bats in the Black Hills relied on a variety of roost types, from healthy live trees to snags at different decay stages depending on reproductive stage and ambient weather. Our study highlights the importance of considering diverse contexts when characterizing habitat preferences, particularly for endangered species in a rapidly changing world.