A decade of monitoring the remnant Victorian population of the brush-tailed rock-wallaby (Petrogale penicillata)

Abstract

Historically, the brush-tailed rock-wallaby (Petrogale penicillata), occurred throughout the Great Dividing Range from southern Queensland to western Victoria. Within Victoria, this extensive range has now contracted to a single remnant population in the Little River Gorge in East Gippsland, and the species is classified as ‘Critically Endangered’. Here we summarise the key results from 10 years of monitoring and management of the Little River Gorge population. The count of individuals detected biannually rose from one in 2000 to 12 in 2008, but this increase was at least partially due to variation in monitoring methodology. Apparent mortality rate in the first year of life was 69%, suggesting that predation was the strongest extrinsic factor limiting the population. Fecundity rate among fertile females was estimated at 1.14 births per annum. Rainfall did not significantly predict birth rate, juvenile mortality or sex ratio. Comparison of three monitoring techniques (cage traps, remote camera surveillance and genetic analysis of scats) revealed that each detected a different subset of the population in this study. These techniques should be considered complementary, rather than substitutable, in future monitoring of small Petrogale populations.