Social calls characterisation of the island-restricted Madeiran Pipistrelle (Pipistrellus maderensis)

The natural history of island-restricted bats remains poorly understood, particularly with regard to their social behaviours. Here, we present the first description of the social calls of aggression, distress and isolation in the IUCN endangered Madeira pipistrelle (Pipistrellus maderensis, Dobson, 1878). We recorded P. maderensis during two nights of mist netting at two different sites on Madeira Island, Portugal. We classified species-specific calls into four main categories of social calls, with variations (A; B; C.i; C.c; D) indicating specific types of behaviour. This information on the social call structures and variability of P. maderensis not only enhances our understanding of social communication but also provides valuable insights into its behavioural ecology, helping researchers to assess its habitat use and social dynamics. These findings, together with our recordings, which are made publicly available in an open repository, provide an important basis for further research and conservation efforts aimed at protecting this endemic island species and its unique ecological niche.