Selection of foraging habitat by female little brown bats (Myotis lucifugus)

Abstract

Characterizing habitat use is a key component to quantifying the niche, ecological interactions, and conservation needs of a species. Habitat selection is the disproportionate use of habitat types, whereby animals select higher-quality habitats within a landscape mosaic. For insectivorous bats, selection of foraging habitat is likely due to variation between habitat types in the distribution and abundance of prey, as well as differences in how effectively bats can move through, and forage in, different landscapes. Due to their cryptic nature and rapid nocturnal flight, detailed knowledge about fine-scale habitat selection of bat species is lacking. We used data-logging telemetry receivers to assess selection of foraging habitat by the little brown bat, Myotis lucifugus, in the Badlands and Missouri River Valley of North Dakota. Bats were captured at maternity roosts, fitted with radiotransmitters, and tracked for 11 nights at each site. Habitat selection was assessed based on selection ratios of used and available proportions of habitat, which were characterized in terms of both composition and structure. Eigenanalysis of selection ratios was used to further evaluate individual variation in habitat selection. Foraging female M. lucifugus primarily selected edge habitats and nearby water sources. Pregnant bats selected edges bordering grass or herbaceous habitats. Lactating bats selected water and edge habitat within close proximity to the roost. Selection of nearby water resources by lactating bats under the constraints of nursing is consistent with previous studies. While there were ecologically consistent trends across bats, individuals varied in some aspects of their habitat selection.