Insights into the habitat associations, phylogeny, and diet of Pipistrellus maderensis in Porto Santo, northeastern Macaronesia

Around 60 % of all bat species occur in islands, and nearly one in four isan insular endemic. Bats are often the only native terrestrial mammals inoceanic islands, and despite increasing anthropogenic pressures, little isknown about the distribution, natural history, and population status of mostinsular bat populations. The sub-tropical archipelago of Madeira is composedof the volcanic islands of Madeira, Porto Santo, and Desertas and ishome to the Macaronesian endemic Pipistrellus maderensis, to the endemic subspecies Nyctalus leisleri verrucosus, and to Plecotus austriacus. Pipistrellus maderensis is knownto both Madeira and Porto Santo, whereas the other two species have onlybeen recorded in the former. However, no bats have been recorded in Porto Santofor over 15 years, raising fears that bats are probably extinct in theisland. In July 2021, we conducted an island-wide acoustic survey usingAudioMoth passive acoustic recorders, leading to the detection ofPipistrellus maderensis in 28 out of the 46 sampling sites (60 %). The species' activity wasstrongly associated with artificial water sources, and genetic samples fromsix captured individuals revealed that the populations of Pipistrellus maderensis in Porto Santo andMadeira have a close phylogenetic affinity. Furthermore, using DNAmetabarcoding, we found that the species feeds on a wide variety of insects,including several economically important pest species and disease vectors.These findings emphasise the need to target more conservation and researchefforts towards extant island bat populations and the potential ecosystemservices they provide.