Seasonal occupancy of abandoned mines by cave-dwelling bats in the western Blue Mountains, New South Wales

Abstract

Cave-dwelling microbats are known to occupy abandoned mines, which can be important habitat for threatened species. Surveys and monitoring between 2012 and 2014 in Mugii Murum-ban State Conservation Area identified use of three adits from historic mine workings by three species: Chalinolobus dwyeri, Miniopterus orianae oceanensis and Rhinolophus megaphyllus. One of the adits is a potential small maternity roost for the threatened M. o. oceanensis, as indicated by captures of pregnant females in December 2014, as well as increased emergence counts and call activity in spring compared with autumn. While there were some signs of reproducing R. megaphyllus at the adits (a single pregnant female in late October, and postlactating females and juveniles in February) the complete absence of females during December trapping indicated otherwise. Use of the three adits was typical for roost and access preferences of the species, with only R. megaphyllus occupying a doored adit and all species recorded at a large unobstructed adit, and a shallow adit likely only used as a night roost by all species.