The western ringtail possum, Pseudocheirus occidentalis, and the quokka, Setonix brachyurus, case studies: Western Shield review—February 2003

Abstract

Case studies are presented for the western ringtail possum, Pseudocheirus occidentalis, and the quokka, Setonix brachyurus. The ringtail case study summarises information from a recent review of the species’ distribution and conservation status, collates information on ringtail populations within the areas covered by the Department of Conservation and Land Management’s (CALM) fauna recovery program, Western Shield, and draws extensively on the recent findings from translocation programs. Critical to the case study is the finding that (i) monitoring of the response to fox control programs is poor, or non-existent, at all known sites, with the exception of research specific translocation sites. This may reflect the difficulty in censusing and monitoring this species; and (ii) translocation success has not been demonstrated at any translocation release site and the primary translocation site, Leschenault Peninsula Conservation Park, has suffered a significant population decline. Hypotheses are proposed to explain this decline and, in the absence of demonstrated translocation success, critical components for monitoring western ringtail possum translocations are recommended. Monitoring protocols are also recommended for other extant populations within the species’ geographic range. The quokka case study also summarises information from a recent review of the species’ distribution and conservation status and collates information on quokka populations within the areas covered by Western Shield. The case study also draws extensively on the findings from recent research from the northern jarrah forest. As for the ringtail case study, the quokka case study found monitoring is non-existent or poor, or ad hoc at best, at all known sites, with the exception of research specific sites within the northern jarrah forest. Consistent with recently published research findings, intervention management is recommended at these northern jarrah forest sites. An active adaptive management framework, using fire as a tool to create the preferred structural habitat mosaic, is recommended. Both case studies highlight the need to review data collection, collation, analyses and reporting processes to ensure data are collected in a manner to allow objective analyses and scrutiny. Under this proposed scenario, any conservation gains can be quantified and documented. Conversely, in circumstances where desired outcomes have not been met, the failure to meet set goals can be identified and mechanisms can be implemented to improve conservation management.