Predicting suitable release sites for assisted colonisations: A case study of eastern barred bandicoots

Abstract

Assisted colonisations are increasingly being used to recover endangered or functionally extinct species. High quality habitat at release sites is known to improve the success of assisted colonisations, but defining high quality habitat can be challenging when species no longer inhabit their historical range. A partial solution to this problem is to quantify habitat use at release sites, and use results to inform assisted colonisation in the future. In this study, we quantified habitat use by the eastern barred bandicoot Perameles gunnii, functionally extinct on the Australian mainland, immediately after translocation to an island ecosystem. The release site, Churchill Island in Westernport, Victoria, Australia, has a mix of open woodlands and open pasture, providing a range of habitat conditions considered appropriate for nesting and foraging. A total of 16 bandicoots were radio-tracked for 30 d immediately post-release. Early survivorship was high (94%), with males found to have larger home ranges and move greater distances from their first nest than females. Males and females initially used structurally complex habitats for nesting and foraging; as they became more established, males moved further from their release point and both sexes increased their use of open habitats during nightly activity. Female home ranges had limited overlap, suggesting intra-sexual territoriality. Males exhibited larger overlapping home ranges. Our results assist in quantifying habitat use of bandicoots immediately postrelease and will be used to inform future assisted colonisations of the species to larger islands, in the presence of feral cats.