Headstarting as a cost-effective conservation strategy for an endangered mammal.

Summary Introduced predators threaten prey species worldwide, but strategies to protect vulnerable wildlife from introduced predators can be expensive, time-consuming, and logistically difficult 1 , 2 . Novel conservation strategies that reduce predation affordably and efficiently must be explored. ‘Headstarting’ is one such strategy, whereby prey are isolated from predators only during the critical early life stage before being returned to the wild, thus improving juvenile survivorship and recruitment to contribute to an increase in population growth 3 . Headstarting is a particularly useful conservation strategy for species facing higher levels of a threatening process during only the early part of their life history when mortality rates are higher, and has demonstrably improved conservation outcomes for birds and marine species 3 , 4 . Here we report findings from the first known headstarting program for a terrestrial mammal, the endangered bridled nailtail wallaby (Onychogalea fraenata) at Avocet Nature Refuge (henceforth ‘Avocet’) in Queensland, Australia.