The Wyoming Game and Fish Department, in cooperation with personnel from the University of Wyoming Haub School of Environment and Natural Resources and the Bureau of Land Management, captured and collared 70 adult doe mule deer for research purposes in mid-December. This is the first large-scale movement study of mule deer in the Sheridan Region.
The project is part of the statewide Mule Deer Initiative, a program created to address declines in mule deer populations in Wyoming. The Upper Powder River mule deer herd – Hunt Areas 30, 32, 33, 163 and 169 - was recognized as a herd of interest in the Sheridan Region in 2014. Wildlife managers decided upon a three-year monitoring project to evaluate the condition of the herd, identify factors influencing animal survival, learn about seasonal movements and habitat preferences and study the dynamics of chronic wasting disease on the herd.
This herd has been below population objective (18,000) since the early 2000s, with the 2017 postseason population estimated at approximately 11,000 deer. Management actions implemented to address the stagnant population include the near elimination of doe harvest, conservative general license deer seasons, liberalized mountain lion, black bear, white-tailed deer and elk seasons, as well as the initiation of habitat improvement projects.
The capture operation took place on Dec. 13 and 14 at several locations between Buffalo and Kaycee. A professional wildlife capture crew caught the deer via a helicopter using net guns to ensnare the animals and secure them for transport. Once secured, the animals were mildly sedated and flown one or two at a time, to a designated staging location where waiting personnel unloaded them.
Each deer was fitted with a GPS neck collar that will track its movements for the next three years. Various measurements were taken including weight, length and girth. Blood samples were collected and will be analyzed for genetics. In addition, fecal samples were collected to test for parasites and a small sample of rectal tissue was collected to test for chronic wasting disease. An ultrasound was also performed to measure subcutaneous body fat to assess body condition.
“Surprisingly, the study produced results almost immediately when a number of deer were found with no rump fat,” said Sheridan Region Wildlife Coordinator Dan Thiele. “This was unexpected given reasonable precipitation this year. The study may help identify limitations in habitat which lead to poor body condition that can affect winter survival, fawn production and birth weights.”
The collars can transmit by very high frequency (VHF) to allow tracking with a receiver and they also collect and store a GPS location every two hours. This data will not be seen and analyzed unless a deer dies or until the end of the study when the collar is collected.
But biologists will see regular location updates throughout the study with another communication method provided by the collar.
“The radio collars collect GPS location data every two hours for approximately three years and store the data on the collar. Real-time GPS location data is collected every six hours and is transmitted via satellite every 36 hours,” said Buffalo Wildlife Biologist Cheyenne Stewart. “I can then view those locations on my computer. During the project we’ll get broad-scale movement data, but at the end of the study we will get the two-hour locations. When we download the two-hour location points we will be able to analyze finer scale movement and habitat use patterns, and maybe even identify fawning locations.”
“Our hope is to recapture these deer annually at the same time of year for the duration of the study, so four captures total over three years,” Stewart continued. “The reason we want to recapture every year is to repeat the ultrasound and body condition measurements. That way we can learn how deer movement, habitat selection and weather influence body condition of deer coming off summer range.”
Funding for the project has been provided by the Mule Deer Initiative through the Wyoming Game and Fish Commission, the Bureau of Land Management and the Wyoming Sportsman’s Group based in Campbell County.
“The success of this project relied heavily on the participation of local landowners willing to allow us to capture deer on their property, as well as set up staging locations with a large number of trucks, trailers, equipment and personnel,” said Sheridan Region Wildlife Coordinator Dan Thiele. “We truly appreciate each of them allowing us access to their property.”
Regular updates on the project will be provided to the public over the next three years and a detailed update will also be featured at the annual Buffalo and Kaycee season setting meetings this coming spring.