Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

Reintroductions have been used (with varying success) to re-establish species into parts of their natural range where they no longer occur. Improvements to the success of reintroductions require close monitoring of experimental releases to test specific hypotheses about factors that may improve the likelihood of establishing self-sustaining populations. The South Australian mainland tammar wallaby has been extinct in the wild since the 1930’s. Habitat clearance and predation by introduced foxes were thought to be the major causes of extinction. Fortunately, a wild population of this species were found living in New Zealand, and eighty two were captured and brought back to Australia to establish a captive breeding population. Subsequently, forty six wallabies were used in an experimental reintroduction into their former range following a fox control program. The release tested whether wallabies in established social groups (versus groups of animals unfamiliar with each other) would have an advantage against predation by foxes that evaded the fox-control or dispersed into the release site. The wallabies were radio-tracked intensively for twelve months following release. Foxes were one of two major causes of mortality, but survivorship did not differ between the experimental treatment groups. We will describe the movement patterns and dynamics among the treatment groups, leading to the establishment of a small breeding population of M. e. eugenii in its former range.