A silhouette of a moose against a cloudy background

Demographics and Nutritional Response of Moose to Beetle Kill in the Snowy Range

A mother moose faces the camera. The moose is wearing a GPS collar around her neck. Her calf stands closeby, looking to the left. The moose pair has a beetle-killed forest stand at their backs. Some of the trees are live and some are dead.


The Snowy Range moose herd encompasses individuals within the Sierra Madre, Snowy, and Laramie ranges of southeast Wyoming. Though most moose herds in Wyoming have recently experienced population declines, it is generally thought that the Snowy Range moose herd has remained strong and healthy. The population underwent rapid growth following its original colonization of the area in the 1980s and the area has become prized by hunters for its abundance of prime bulls. Nevertheless, the Snowy Range herd is more difficult to count than many other larger herds in western Wyoming because of the expansive conifer forests. As a consequence, the actual performance of this herd remains unclear.


The impetus behind the project is to determine the trend of the population, and how habitat, harvest, and environmental factors are influencing it. We are approaching this question in a novel way through consecutive measures of habitat selection, nutritional condition (i.e., percent body fat), reproductive success, and survival from the same individuals. By monitoring nutritional condition relative to an animal’s space use and reproductive success, we can develop an estimate of where the population stands relative to what the habitat can support (i.e., nutritional carrying capacity). This will in turn provide biologists with valuable information to aid in management decisions for this important moose herd that is beloved by non-consumptive recreationists and hunters alike.


A prior study of moose in the Snowy Range, conducted by Philip Baigas, revealed that both coniferous and riparian habitat types are important to this herd. Much of the coniferous forest in the Snowy Range consists of lodgepole pine, which has been widely affected by the mountain pine beetle (also known as the bark beetle) between the previous moose study and the present day. There are many ways the glut of dead trees may influence how a moose moves through and forages in a forest. New gaps in the canopy from lost needles may positively affect moose by promoting growth of valuable forage plants. These new gaps in canopy, however, may reduce shade for moose—a northern-adapted species that is sensitive to warm temperatures.


We are combining the current study and the GPS collar data from the previous moose study to reveal what effect the bark beetle eruption has on moose behavior. Little research has been done on how the bark beetle has influenced large mammal ecology; we are excited to examine this by comparing movement behavior of moose now with moose a decade ago, as well as look at how habitat selection strategies of individuals can influence body condition and reproductive capacity. Moose collars (and their stored data) were reclaimed in March of 2017 for analysis. New collars with a satellite uplink were put on some of the moose when their old collar was removed— these new “live” collars will help us answer questions about what causes adult moose to die in the Snowies. Until recently the exact cause of death for many project moose was unknown because we didn’t know about most mortalities until well after they occurred. If you find a collar in the field or harvest a collared moose, please contact the Coop Unit so we can download the stored data. We also are keen to hear reports of collared moose sightings. Each moose collar has a colored tag on the right-hand side. By noting the color and number, we can identify the individual. If you are willing, please send tag information, along with the date, general location, and a photo to [email protected] and we will be happy to provide some information about that moose’s participation in the study.



Reports & Publications

December 2016 Wyoming TWS Poster

January 2016 Update
March 2015 Snowy Range Moose _ Capture Report


Alex May
[email protected]
Snowy Range Moose Project
Wyoming Cooperative Fish and Wildlife Research Unit
University of Wyoming


Project Lead

Alex is smiling at the camera. The peaks of the Snowy Range, his study area, are visible in the background.

Alex was the project lead for the Snowy Range Moose Project. He came to Laramie to pursue his Master’s degree in the Coop Unit after four seasons as the wildlife crew lead at Grand Teton National Park.


March 2015- 30 GPS collars deployed on moose in the Medicine Bow National Forest and surrounding public and private lands

July 2015- Calf recruitment survey

July-August 2015- Habitat sampling

August 2015- Second calf recruitment survey

December 2015- First recapture of original 30 moose.

March 2016- Second recapture

June-August 2016- Second round of habitat sampling

July 2016- Third calf recruitment survey

August 2016- Fourth calf recruitment survey

December 2016- Third recapture

March 2017- Final capture; GPS collars removed from study animals and replaced with satellite-uplink collars with automated drop-off.

May 2017 and beyond- Analysis and reporting of project findings. Continued monitoring of study animals to determine cause of death for those that do not survive the next three years.

Funding & Partners

Wyoming Game and Fish Department • Wyoming Governor’s Big Game License Coalition • Albert W. Franzmann and Distinguished Colleagues Memorial Award