Reintroduction and establishment of the western barred bandicoot Perameles bougainville (Marsupialia: Peramelidae) at Shark Bay, Western Australia

Abstract

The western barred bandicoot was reintroduced to the Australian mainland in 1995 after an absence of at least 60 years. The new population was derived from 14 animals, reintroduced to Heirisson Prong from Dorre Island in Shark Bay, Western Australia. Introduced predators (the European red fox and the feral cat) were controlled at the reintroduction site, but European rabbits were not. A large fenced area of natural vegetation within the reintroduction site was used as a secure refuge from mammalian predators. Bandicoots were released from this predator refuge to the 12 km 2 conservation site. Dispersal from the point of free release was minimal. The reintroduced population has persisted for 4 years and increased, with at least 175 bandicoots recruited to the population in this time. The recapture rate of marked bandicoots was low, suggesting that adult mortality was high. Reproductive output at Heirisson Prong appeared greater than that of the two surviving wild populations on Bernier and Dorre Islands. Litter size was similar, but there was an extended annual breeding season at the reintroduction site. Body condition of reintroduced and wild bandicoots were similar, although there was some indication that reintroduced males may have been in poorer condition than their island counterparts. The litter size of bandicoots increased with a decrease in rabbit abundance, however, bandicoots were able to reproduce, maintain condition, and sustain recruitment to allow the population to increase despite the presence of rabbits. Two fox incursions occurred during the 4-year period of establishment, and feral cats were present on occasion in low numbers. Feral cats may be responsible for a lower rate of population increase than that observed on predator-free Dorre Island. Ongoing predator control is essential for any mainland reintroduction of bandicoots.