Growth of the Black Wallaby ( Wallabia bicolor ) population at the Cranbourne Gardens (Royal Botanic Gardens Victoria), after the implementation of fox control

Abstract

SummaryCoincident with a decade of introduced predator suppression, there was an increase in populations of a range of native mammals at the Royal Botanic Gardens Victoria (Cranbourne). A small, regionally significant population of the Black Wallaby (Wallabia bicolor) grew exponentially from an estimated 0.6 individuals km−2 in 2001 to more than 70 km−2 in 2013. The measured mean annual instantaneous rate of increase derived from a regular spotlight survey was ˜0.37 and extrapolates to a doubling of the population approximately every 2 years. There was little indication that growth was abating as the population increased. Modelling predicted that in the absence of a decline in fertility or natural increase in mortality one third of the population would need to be shed annually to moderate or reverse growth and allow vegetation communities and small mammal habitats to recover.