Bat-on-bat predation in the greater noctule Nyctalus lasiopterus

The diet of the greater noctule Nyctalus lasiopte- rus was investigated by morphological inspection of prey remains and DNA barcoding from faecal pellets. Morpho- logical analyses confirmed the occurrence of both inverte- brate and vertebrate prey. Molecular analyses were only conducted on vertebrate remains, and revealed the presence of both avian and chiropteran prey. Bird remains belonged to two resident, cavity-nesting species (Eurasian nuthatch Sitta europaea and Eurasian blue tit Cyanistes caeruleus), suggesting bats also hunt within tree cavities. Remarkably, bat hairs recovered from one pellet were genetically iden- tified as belonging to the common pipistrelle Pipistrellus pipistrellus, representing the first molecularly confirmed evidence of bat-on-bat predation by a European bat species. Although based on a low sample size, these findings expand the known trophic niche of N. lasiopterus and suggest that vertebrate predation by insectivorous bats may be more widespread than currently documented.