Chronic wasting disease (CWD) is an infectious transmissible spongiform encephalopathy (TSE) afflicting members of the family Cervidae, and causes neurodegeneration and ultimately death. While there have been no reports of natural cross-species transmission of CWD outside this group, we addressed the role of white-tailed deer (Odocoileus virginianus) carcasses as environmental sources of CWD in Wisconsin. Our objectives were to estimate rates of deer carcass and gut pile decomposition in the environment, characterize vertebrate scavenger communities, and quantify the relative activity of scavengers to determine CWD exposure risk. We placed 40 disease-free deer carcasses and nine gut piles in the CWD-affected area of Wisconsin from September to April in 2003 through 2005. We used photos from remotely operated cameras to characterize scavenger communities and relative activity. We used Kaplan-Meier survival analysis and a generalized linear mixed model to quantify the driving factors and rate of carcass removal (decomposition) from the environment.
We recorded 14 species of scavenging mammals (six visiting species), and eight species of scavenging birds (14 visiting species). Prominent scavengers included American crows (Corvus brachyrhynchos), raccoons (Procyon lotor), and