Data from: Endemic chronic wasting disease causes mule deer population decline in Wyoming

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.