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Endemic chronic wasting disease causes mule deer population decline in Wyoming

October 19, 2017

Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting white-tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), Rocky Mountain elk (Cervus elaphus nelsoni), and moose (Alces alces shirasi) in North America. In southeastern Wyoming average annual CWD prevalence in mule deer exceeds 20% and appears to contribute to regional population declines. We determined the effect of CWD on mule deer demography using age-specific, female-only, CWD transition matrix models to estimate the population growth rate (λ). Mule deer were captured from 2010–2014 in southern Converse County Wyoming, USA. Captured adult (≥ 1.5 years old) deer were tested ante-mortem for CWD using tonsil biopsies and monitored using radio telemetry. Mean annual survival rates of CWD-negative and CWD-positive deer were 0.76 and 0.32, respectively. Pregnancy and fawn recruitment were not observed to be influenced by CWD. We estimated λ= 0.79, indicating an annual population decline of 21% under current CWD prevalence levels. A model derived from the demography of only CWD-negative individuals yielded; λ = 1.00, indicating a stable population if CWD were absent. These findings support CWD as a significant contributor to mule deer population decline. Chronic wasting disease is difficult or impossible to eradicate with current tools, given significant environmental contamination, and at present our best recommendation for control of this disease is to minimize spread to new areas and naïve cervid populations.

Publication Year 2017
Title Endemic chronic wasting disease causes mule deer population decline in Wyoming
DOI 10.1371/journal.pone.0186512
Authors Melia DeVivo, David R. Edmunds, Matthew J. Kauffman, Brant A. Schumaker, Justin Binfet, Terry J. Kreeger, Bryan J. Richards, Hermann M. Schatzl, Todd Cornish
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS ONE
Index ID 70192640
Record Source USGS Publications Warehouse
USGS Organization Coop Res Unit Seattle; National Wildlife Health Center