Abstract
Translocation of the threatened western ringtail possum (Pseudocheirus occidentalis) has been instigated as a management strategy to ameliorate the effects of habitat loss in coastal regions of south-west Western Australia. Re-establishment of viable populations within the species' inferred pre-European geographic range is proving difficult due, in part, to predation by exotic and native carnivores. We monitored the health of western ringtail possums both before and after translocation to determine whether individual health components or population-level disease status contributes to the low translocation success. Common brushtail possums already resident at the release sites were also health-screened to investigate the likelihood of interspecific disease transmission. No evidence of exposure to Toxoplasma gondii or Leptospira serovars was found; neither was infection with Salmonella spp. or Chlamydiales spp demonstrated. One brushtail possum tested positive for Cryptococcus antigen. Survivorship modelling revealed a negative relationship between lymphocyte counts and translocation success for western ringtail possums. Moreover, site differences in haematological parameters suggested habitat quality for this species may be lower at the translocation sites than at the sites where possums are being displaced by clearing for land development. The numbers of brushtail possums resident at the release sites also affected survival of translocated ringtails. Implications of these results for future management of the western ringtail possum are discussed.