Media release

From: The Royal Society

Density independent decline from an environmentally transmitted parasite

Environmentally transmitted parasites can cause the decline of animal populations independent of their density. Over a seven-year period, the prevalence of sarcoptic mange in a bare-nosed wombat population in Tasmania was high (27%), the wombat population declined by 80%, and experienced a 55% contraction in range within the study area. The population decline was independent of wombat abundance. We then combined our results with other studies on wombats and mange, finding wombat populations may be at risk of decline when mange prevalence exceeds 25%. Prevalence may thus provide a guide for when there is a conservation threat.

Mortal wombat – Social distance might not protect wombats from infectious disease. The prevalence of sarcoptic mange, a skin condition similar to scabies in humans, was measured in a bare nosed wombat population in Tasmania over seven years, and compared to population decline. When mange prevalence was high (27%), a population decline of 80% was observed. This decline was independent of wombat abundance, suggesting wombat populations may be at risk of environmentally transmitted disease irrespective of population density.