Understanding the physiological impacts of stress on the Australian marsupial species, the Koala (Phascolarctos cinereus), within New South Wales and South Australia

Abstract

The koala (Phascolactos cinereus) is currently listed by the IUCN as vulnerable toextinction with a decreasing population trend. This listing can be attributed to both therecent climate trends impacting ecosystems, and human induced environmental changefrom extensive land clearing and habitat fragmentation. These have both been proven toinduce stress, which in turn influences the onset of disease. This study performed aretrospective analysis whereby admission records for 12,543 wild, rescued koalasadmitted into clinical care within New South Wales were studied in order to determinetrends in clinical admissions and diagnosis over a period of 29 years. Results indicatedthat between all three locations (Port Stephens, Port Macquarie and Lismore), the mostcommon prognosis for koalas admitted into care was disease, the most common diseasefor koalas admitted into care was signs of chlamydia, and the most common outcome forkoalas admitted into care was released. Within Port Stephens, mature aged and femalekoalas were found to have more disease than any other age or gender, while juvenile agedand male koalas were found to be released more than any other age or gender.Additionally, there were fewer koalas with disease and fewer koalas released in PortStephens as each year progressed. Within Port Macquarie, mature aged and male koalaswere found to have more disease than any other age or gender, while juvenile aged andfemale koalas were found to be released more than any other age or gender. Additionally,there were more koalas with disease and fewer koalas released in Port Macquarie as eachyear progressed. Within Lismore, adult aged and female koalas were found to have moredisease than any other age or gender, while joey aged and male koalas were found to bereleased more than any other age or gender. Additionally, there were more koalas withdisease and fewer koalas released in Lismore as each year progressed. Determiningtrends in clinical admissions and diagnosis over such a substantial period of time is animportant determinant for the continuing decline of koalas throughout Australia, and inparticular New South Wales. It is integral that any further decline of koala populations isprevented, however this can only be achieved through informed recommendationsthrough research projects such as these.

Date of Award	2019
Original language	English