Moths Consumed by the Barbastelle Barbastella barbastellus Require Larval Host Plants that Occur within the Bat's Foraging Habitats

Abstract

Loss of foraging habitat and reductions in insect prey are key factors responsible for declines in bat populations. Identifying important bat foraging habitats and the ecological requirements and conservation status of prey provides evidence for appropriately targeted conservation management strategies. We examined the foraging habits of the barbastelle, Barbastella barbastellus, at the northern edge of its European range using a combination of radio tracking, to determine home range use and habitat selection, and DNA metabarcoding, to identify prey items consumed. Riparian vegetation and broadleaved woodland were the habitat types most strongly selected by foraging bats. Hedgerows within pastoral habitats were also important foraging features within the landscape. We identified 120 different prey items within faecal pellets, the majority of which were moths (97.5%). The large majority (97%) of prey items consumed have larval stages dependent on host plants that are typically found within habitats selected by foraging B. barbastellus. Almost half of all moth prey species identified have undergone considerable population declines in recent decades. We present the most comprehensive list to date of prey consumed by B. barbastellus and provide evidence that conservation management policies should target the protection and enhancement of key B. barbastellus foraging habitats within a 6.5 km sustenance zone around maternity roost sites. Riparian habitat, broadleaved woodland and linear landscape features such as hedgerows should be managed to improve their value to foraging B. barbastellus as well as the developmental stages of their preferred moth prey.