The brush-tailed bettong (Bettongia penicillata), or woylie, is an endemic Australian marsupial that has recently suffered a large population crash in the Upper Warren region of Western Australia. Research has shown that both the declining Upper Warren population of brush-tailed bettongs and a stable population at Karakamia Wildlife Sanctuary are infected with a novel Trypanosoma sp., and the declining Upper Warren population was found to have a higher prevalence of trypanosome infection that that of the stable Karakamia population. In this study, further work was done to see if 1) the prevalence and intensity of trypanosome infection still differed significantly between the two populations, 2) if the prevalence and intensity were indicative of the overall health of the population, and 3) the infection rate varied seasonally. Using light microscopy, no blood samples taken from Karakamia were found to show evidence of trypanosome infection, while an average of 23.5% and 28.6% of samples taken from Keninup in May 2009 and October 2009, respectively, showed evidence of trypanosome infection. Individual parasitemia levels in those infected slides were extremely low, and no seasonal variation in prevalence or intensity could be found. While there are significant differences in trypanosome prevalence (and therefore intensity) between the two populations, this does not mean that trypanosomes are the ultimate cause of the population crash; co-infection with other protozoan parasites or condition-dependent virulence are both possible alternate causes of the crash. Further research and analysis will help to formulate successful conservation policies that can facilitate the recovery of the critically endangered woylie populations.
Animal Sciences | Biology
Chiasson, Melissa, "Prevalence and Intensity of Trypanosome Infections in Stable and Declining Populations of Brush-Tailed Bettongs (Bettongia Penicillata)" (2009). Independent Study Project (ISP) Collection. 776.