Woylie
(also known as brush-tailed bettongs, Bettongia
penicillata) populations have undergone substantial declines over the past
decade, with the cause of the declines attributed partly, but not entirely, to
predators. Woylie declines displayed density-dependence, and a spatiotemporal
pattern of decline, similar to declines patterns observed in other disease-driven
declines. Three Trypanosoma spp. have
been identified from woylies so far, and one of these – T. copemani – has shown pathogenic potential. In this study, we asked
if patterns of Trypanosoma infection
were associated with patterns of decline throughout the decline region. If
trypanosomes were associated with woylie declines, we expected that infection prevalence
would be highest at the peak of the decline, and prevalence would decline as
the declines progressed through the region. Species-specific PCRs were run for
each of the three Trypanosoma species
from woylie blood samples collected between 2006 – 2012 from the Upper Warren
region (south-west Western Australia). We found a strong association between
spatio-temporal patterns of woylie declines and the prevalence of T. copemani, but not the other two Trypanosoma spp. We consider this further support for the
hypothesis that T. copemani is
indirectly involved in the woylie declines, probably through enhancing the predation
risk of infected individuals.