Assemblage structure and use of anthropogenic roosts by bats in the Eastern Carpathians: Case study in the Bieszczady National Park (SE Poland)

Abstract

In relation to almost completely reduced anthropogenic pressure after 1944 and the consequently low number of present settlements, impoverishment of the bat (Mammalia: Chiroptera) fauna has been suggested for the Western Bieszczady Mountains (Mts), southeast Poland. During a field study in 2009–2011, we recorded 15 bat species within the Bieszczady National Park and 19 in total (i.e. all but one or two expected for the Bieszczady Mts), including a locality at a cave near the park border. At 26 (72%) of 36 localities sampled over water, forest roads and glades, in 278 mist net hours, we captured 159 bats representing 12 species. Species most frequently sampled and most abundant in captures were Myotis brandtii and M. daubentonii (both over 50% of localities and 80% of bats in total). Most of the captured bats were males (73%) and adult individuals (85%). Fifty percent of M. daubentonii (both sexes) and several males of M. brandtii, netted over streams, were soiled with fresh clay, indicating day roosts of these bats were likely located in rocky crevices at river banks. We found bats (six species) or their faeces in 28 (48%) of 58 inspected roosts in buildings. Vespertilio murinus was the most abundant and most frequent species. The same number of species (five) used farm buildings and houses. Most bats found at roosts were adult males either solitary or in two colonies of V. murinus. Despite the high number of species recorded, we confirmed the impoverishment of the attic dwelling species set. Although no church attics, frequently utilized by colonies of Rhinolophus hipposideros and M. myotis in the other Carpathian regions, are present in the Bieszczady National Park, local buildings as a limited source of roosting site are important for bat conservation.