Output list
Doctoral Thesis
Published 2015
A wide range of factors, including individual animal health, genetic diversity and demographics, are associated with wildlife population declines and investigation of these factors may be more sensitive in detecting early impacts on wildlife populations, than estimates of population size alone. Defining wildlife population health as the ability of a wildlife population to remain viable in the long term, this project developed and implemented a holistic health assessment framework for platypuses to gather baseline data, to investigate environmental, temporal and individual patterns within this data, and to provide insights into potential threatening processes. Platypus distribution and population density in two river catchments in northwest Tasmania were investigated in a live capture/release field study during which 154 individuals were captured. The effect on capture numbers of broad habitat characteristics was investigated. A survey of public sightings provided additional information on platypus distribution and population density. The novel use of in-stream microchip readers to monitor platypus movements/survivorship was developed. Data was collected on the timing and frequency of platypus movements, as well as continued use of monitoring sites by individuals captured in this study and in a study three to six years earlier. The timing of the breeding season in Tasmania was investigated using hormonal, ultrasonographic and remote monitoring observations. Genetic diversity and geographical distribution of alleles at the Major Histocompatibility Complex Class II DZB locus was also investigated. The reliability of existing and novel body condition indices was studied. The prevalence of exposure to a range of parasitic, fungal and bacterial agents was determined. Haematology and biochemistry reference intervals were produced. Little evidence was found that the two study populations were in poor health. Baseline population health data, that for many species has been absent when population declines have occurred, was collected for platypuses; and the project’s general approach will serve as a template for similar research in other species.