Small mammals and predator exposure


This week’s featured research article has just been published in the Journal of Applied Ecology by SA researchers and examines predator exposure improving anti-predator responses in a threatened mammal. Exotic predators can have devastating impacts on native prey species and thwart reintroduction efforts, in part due to prey naïveté caused by an absence of co-evolution between predators and prey. The researchers investigated whether in situ predator exposure could improve anti-predator responses of a predator-naïve mammal by exposing prey populations to low densities of introduced predators under controlled conditions. They reintroduced 352 burrowing bettongs to a 26-km2 fenced exclosure at the Arid Recovery Reserve in South Australia and exposed them to feral cats (density 0.03–0.15 cats/km2) over an 18-month period. At the same time, they translocated a different group of bettongs into an exclosure free of introduced predators, as a control. The study compared three behaviours (flight initiation distances, trap docility and behaviour at feeding trays) of cat-exposed and control bettongs before the translocations, then at 6, 12 and 18 months post-translocation. Cat-exposed bettongs displayed changes in behaviour that suggested increased wariness, relative to control bettongs. At 18 months post-reintroduction, cat-exposed bettongs had greater flight initiation distances and approached feed trays more slowly than control bettongs. Cat-exposed bettongs also increased their trap docility over time. Translocation is recommended as a conservation tool for many threatened species yet success rates are generally low. The study demonstrates that controlled levels of in situ predator exposure can increase wariness in the behaviour of naïve prey. The researchers conclude that the findings provide support for the hypothesis that in situ predator exposure could be used as a method to improve the anti-predator responses of predator-naïve threatened species populations. The article can be downloaded here.