(Wyoming Game and Fish Department)

CASPER, Wyo. — The Wyoming Game and Fish have been studying the Cheyenne River mule deer herd since Dec. 2019. The research began because the area has experienced “poor fawn production and overall depressed deer numbers.”

In 2019, Game and Fish say the fawn-to-doe ratio in Deer Hunt Area 10 in northeast Wyoming stood at 53 fawns per 100 does and that “a higher ratio is needed to maintain or build deer numbers.”

The research project involved captured 35 mule deer from the Cheyenne River herd and fitting them with GPS collars to “identify habitat preferences, daily and seasonal movement patterns and causes of mortality.”

Eight of the collared deer have died, Game and Fish said on Thursday, Feb 4, 2020.

“Eight mortalities of collared deer have occurred with causes identified as predation, vehicle collisions and several unknown,” Game and Fish said. “Two animals were tested for chronic wasting disease and one tested positive, though it is unclear if the disease was the primary cause of death. The collars from these mortalities have been retrieved and deployed on other deer.”

The collars are able to track deer for up to six years depending on how the battery life holds up.

“The collars transmit deer locations every eight hours,” Game and Fish said. “The collars are also recording finer-scale, three-hour movements, which are stored onboard the collar and will be downloaded when the collar is retrieved from a deceased animal or at the end of the study when it is programmed to automatically release.”

Gillette Wildlife Biologist Erika Peckham added: “We have not seen any significant seasonal dispersal of deer away from their original capture areas. Additional data will come later in the study, but so far, the collared deer are showing limited movements, which suggests we might focus attention on habitat in those areas in the future, both measuring current conditions and quality and what potential improvements could be initiated.” 

The Thunder Basin Coal Company have provided funding for the collars in collaboration with the U.S. Forest Service and the Wyoming Sportsman’s Group, according to Game and Fish.