Habitat preferences of bats in anthropogenically altered, mosaic landscapes of northern Poland

Abstract

Few studies refer to the large-scale habitat preferences of bat assemblages in temperate mainland Europe. The study aimed at habitat associations of bats in the postglacial lakelands of northern Poland. Sixty-nine walking transects were divided into sections belonging to 36 habitat classes. Broadband ultrasound detectors were applied to record bat echolocation calls, identified to the species level by spectral analysis. Selection or avoidance of habitat categories was tested using Z statistic with a Bonferroni adjustment, and niche breadth was estimated by calculating Levin’s formula and niche overlap—Pianka index. All bats (except Eptesicus serotinus) selected water bodies. They avoided arable land, coniferous and mixed forests, their edges and suburbs. Nyctalus noctula was the most eurytopic species, using most habitats in proportion to their availability. E. serotinus selected villages and roads in coniferous forests. Narrower habitat niches were occupied by morphologically similar pipistrelles. Pipistrellus pipistrellus preferred tree lines, Pipistrellus nathusii avoided tree lines and villages, and Pipistrellus pygmaeus preferred roads in deciduous forests but avoided tree lines. The most stenotopic Myotis sp. avoided roads in mixed and coniferous forests, tree lines and built-up areas. Most species strongly overlapped in habitat niches, and thus, their resource partitioning was probably based on using different hunting tactics. P. pygmaeus, although considered a sibling species of P. pipistrellus, overlapped in habitat niche much more with P. nathusii. In the latter case, resource partitioning may result from larger differences in body size and frequency of echolocation calls. The importance of water bodies for bats was higher than in Western Europe, and importance of woodland was lower, presumably due to much higher limnicity. The results provide a base for region-specific landscape planning guidelines, applicable to bat conservation.