Release protocols to address hyperdispersal in a novel translocation of a carnivorous marsupial

Abstract

Initial translocations are inherently risky due to uncertainty around species-specific responses to novel environments. Incorporating a range of release protocols can minimise risks of translocation failure. We identified post-translocation hyperdispersal as a risk to the first translocation of the crest-tailed mulgara (Dasycercus cristicauda), an Australian carnivorous marsupial, and tested temporary confinement and releasing females with pouch young as mitigation strategies. We released 16 females with pouch young and 3 males into unoccupied burrows within a 20 km2 feral animal exclosure, either within temporary confinement pens (n = 10) or without confinement (immediate release) (n = 9). Temporary confinement did not influence survival but did influence dispersal behaviour. Thirty-seven percent of translocated individuals (all 3 males, 4 of 16 females) hyperdispersed (3.0–11.6 km) outside the study exclosure after release, including 42% immediate release animals and 29% temporary confinement animals. No males remained in the exclosure at the study end. Confined females settled closer to their release site. Release of females with pouch young led to an increase in the translocated population from 9 to 58 individuals within 4 months. Releasing females with young from geographically distant sites may be important to offset male hyperdispersal. Our results suggest that temporary confinement and translocating breeding females are important release protocols for species with a propensity for hyperdispersal post-translocation.