The results of a recent mule deer collaring study show that despite a reasonably wet 2018, Wyoming mule deer are still suffering.
“Surprisingly, the study produced results almost immediately when a number of deer were found with no rump fat,” Sheridan Region Game & Fish wildlife coordinator Dan Thiele said. “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.”
To learn more about the state’s declining mule deer population, the Wyoming Game & Fish Department, in cooperation with personnel from the University of Wyoming Haub School of Environment and Natural Resources and the Bureau of Land Management, completed the capture and collaring of 70 adult doe mule deer in the Kaycee area for research purposes.
Part of the research involves taking multiple measurements, including rump fat, to assess the body condition of deer coming into the winter season, Game & Fish wildlife biologist Cheyenne Stewart said.
“Each year we will take the same measurements in an effort to understand how annual weather patterns, individual movement patterns and individual habitat use affect the nutritional status of mule deer in the Upper Powder River Herd Unit,” Stewart said.
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 started 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 the population objective of 18,000 since the early 2000s, with the 2017 postseason population estimated at approximately 11,000 deer.
Game & Fish has taken actions to address the stagnant population. The department has nearly eliminated doe harvest and been conservative with general license deer seasons, as well as liberalized mountain lion, black bear, white-tailed deer and elk seasons. They’ve also initiated habitat improvement projects.
The operation was conducted 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. 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.
The collars can transmit by very high frequency 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,” Stewart said. “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 said. “The reason we want to recapture every year is to repeat the ultrasound and body condition measurements. That way we can learn about deer movement, habitat selection and how weather influences body condition of deer coming off summer range.”
Thiele said the success of the project relied on local landowners’ participation and their willingness to allow Game & Fish to capture deer on their property.
“We truly appreciate each of them allowing us access to their property,” Thiele said.
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.