Ecology and conservation of bats in Temotu Province, Solomon Islands and Torba Province, Vanuatu

Abstract

Bats are essential to the functioning of many island ecosystems. A large proportion of Pacific Island Pteropus are endemics, limited in their distribution to single paleotropical islands or close island groups. This subset is also highly threatened by hunting and habitat disturbance. Further exacerbating these threats is a dearth of scientific knowledge that makes long-term management and conservation planning difficult. We aimed to gather data on seven bat species from Nendö, Reef Islands, Tinakula, and Vanikoro (Solomon Islands), and Vanua Lava and Mota (Vanuatu). Between 1990 and 2019 we surveyed bats using walked transects, mist nets and camp counts, and collected data on diets and roosting sites. Data collection targeted four limited range endemics (Nendö tube-nosed bat (Nyctimene sanctacrucis), Banks flying-fox (Pteropus fundatus), Temotu flying-fox (Pteropus nitendiensis) and Vanikoro flying-fox (Pteropus tuberculatus), and three more widespread species (Vanuatu flying-fox (Pteropus anetianus), Pacific flying-fox (Pteropus tonganus) and Fijian blossom bat (Notopteris macdonaldi). Notopteris macdonaldi, P. nitendiensis, P. tonganus and P. tuberculatus were the most common species recorded on transects and mist net surveys. Transect encounter rates were 0.1–4.5km−1 (P. nitendiensis), 0.2–20.0km−1 (P. tonganus) and 0–7.2km−1 (P. tuberculatus). Pteropus fundatus was rarer, we did not detect this species during daytime searches, and it was the least common mist net capture. We documented 65 Pteropus food plants in our study area. Nyctimene sanctacrucis was not detected on Nendö, Tinakula and Reef Islands despite considerable effort. We consider this bat is likely extinct, if in fact it is a distinct species.