Partitioning of foraging resources between sympatric Indiana and little brown bats

Abstract

The partitioning of resources within communities is commonly associated with variation in morphological characteristics between species. However, communities containing morphologically similar species, such as the endangered Indiana bat (Myotis sodalis) and the little brown bat (M. lucifugus) must partition resources in different ways. We examined sympatric populations of M. sodalis and M. lucifugus to determine whether they partitioned their resources through the selection of foraging habitat. Foraging ranges, estimated using 100% minimum convex polygons (MCP) and 95% fixed kernel (FK) models, and foraging habitat selection, estimated using Euclidean distance-based habitat selection analyses, were examined and compared between the species using radiotelemetry. M. sodalis had a mean foraging range area of 375 ± 39 ha and 285 ± 32 ha (MCP and 95% FK, respectively), whereas M. lucifugus had a mean of 2,739 ± 456 ha and 515 ± 78 ha. Both species selected for similar hydric habitats at the landscape level. However, although M. lucifugus specifically selected for open water and bottomland hardwood forests within their expansive foraging ranges, M. sodalis used land cover types as they were available within their smaller home ranges, suggesting that these species use different foraging strategies, partitioning foraging resources through variation in their selection of land cover. © 2013 American Society of Mammalogists.