BOISE — Significant February snowstorms coupled with a cool, wet spring resulted in below-average survival rates for radio-collared mule deer fawns, but the weather had less effect on collared elk calves according to the final survival estimates for the 2018-19 winter.
Idaho Fish and Game biologists monitored 209 mule deer fawns and 196 elk calves that were captured in early winter and fitted with telemetry collars. Statewide, 42% of radio-collared fawns survived through the winter. As wildlife managers expected, it was below the long-term average of 58%. For elk, 69% of radio-collared calves were alive at the end of May.
Those numbers compare with 57% of the fawns and 66% of the calves surviving through May 2018 and 30% and 52%, respectively, through May 2017, which was an unusually harsh winter.
Elk have not been trapped and collared for as many years as mule deer, and elk calves typically survive at a higher rate than mule deer fawns. Since researchers began collaring elk calves in 2014-15, survival has ranged between a low of about 52% in 2016-17 and a high of 84% in 2014-15.
Adult mule deer and elk typically survive at high rates unless it's an extreme winter. Of the 539 radio-collared mule deer does being monitored by Fish and Game researchers, 91% were alive through May 31; 96% of the 578 collared elk cows survived.