The two cryptic species of Pipistrellus pipistrellus (Chiroptera : Vespertilionidae) occur in Italy: evidence from echolocation and social calls

We provide evidence based on the analysis of echolocation pulses and social calls that both cryptic species of pipistrelle P. pipistrellus occur in Italy. We analysed the echolocation calls that 76 bats emitted when they were foraging, emerging from roost or hand-released. Recordings were carried out in Campania, Lazio, Tuscany and Sardinia. Frequencies of highest energy of calls from peninsular Italy bats clearly followed a bimodal normal distribution, and averaged 47.4 kHz and 57.3 kHz, corresponding to the 45 kHz and 55 kHz phonic types respectively. At least in Southern Italy both cryptic species occur in sympatry. Social calls emitted by foraging pipistrelles echolocating at frequencies < 49 kHz and > 52 kHz respectively differed significantly in frequency and time parameters, and could be separated by a discriminant analysis. As these signals are species-specific and are distinct only between the two pipistrelle species, the differences we observed give further evidence that both cryptic species occur in the country.