Mule deer in western Wyoming migrate 18-140 km to high-elevation summer ranges where they access high quality forage and accumulate fat reserves that help them survive the harsh winters. The ability to identify and prioritize these migration routes may improve management and land-use planning.

Researchers begin largest mule deer study in Wyoming

March 13, 2013 5:30 pm  •  

The Wyoming Range mule deer herd, one of the most iconic herds in the West, is shrinking.

That we already know. What wildlife biologists don’t know is why and what can be done.

On Tuesday, researchers from the University of Wyoming and the Wyoming Game and Fish Department began the largest mule deer study in Wyoming and one of the largest in the West. With about $500,000 and three years, the biologists hope to better understand mule deer nutrition and migration patterns. Ultimately, they hope the information will tell them where to focus habitat improvement projects and what areas are most critical to deer survival.

The study is part of the Wyoming Mule Deer Initiative, which began in 2007 in response to declining herd numbers.

“From a management standpoint, if you don’t have all of the information, you’re really fighting yourself,” said Joshua Coursey, president of the Muley Fanatic Foundation. “To put your best foot forward, that information is needed.”

The Muley Fanatic Foundation of Rock Springs gave $20,000 to the project. It was one of eight government and conservation groups to contribute including the Game and Fish Department, the Bureau of Land Management, the Boone and Crockett Club, and the Animal Damage Management Board.

Coursey has spent years watching mule deer numbers decline in the southwest Wyoming herd. The Wyoming Range herd had more than 50,000 deer in the late ‘80s and plummeted to about 30,000 today.

It’s time to start figuring out why, he said.

Researchers began capturing mule deer does Tuesday with helicopters. Biologists measured each doe’s body condition, took blood samples and placed a GPS collar around its neck. They plan to capture 70 females this spring. They will recapture all of the surviving does with collars in the fall. New deer will be caught to replace those that may have died. The study captures will continue until spring of 2015, said Gary Fralick, wildlife biologist with the Game and Fish Department.

GPS collars will record each doe’s location every three and a half hours for two years. The information will show biologists exactly where does migrate and how they behave around human development, Fralick said.

Body condition information will tell biologists how good the habitat is on summer and winter ranges and the spring and fall migratory regions. This will also help researchers compare the northern and southern winter ranges. The northern winter range near La Barge has more human activity such as gas development with milder winters. The southern winter range near Kemmerer has relatively little development but winters tend to be harsher, Fralick said.

Body condition tells researchers if a doe can survive and also shows if a female can carry a fawn to delivery. If a mother lacks nutrition, the baby is the first thing to go, said Kevin Monteith, lead researcher for the project from the University of Wyoming Cooperative Fish and Wildlife Unit.

Hard winters and human development certainly play roles in mule deer survival. But, researchers want to know the details of how those factors impact deer nutrition, Fralick said.

“This study will answer a lot of questions that we have speculated on without data,” he said.


Link to original story