Meeteetse Moose Project
Over the last two decades, nearly half of the moose populations in their southern extent have declined. Despite widespread interest in moose conservation, the complexities of how moose are influenced by their environment makes for a challenging assessment of efforts needed to bolster moose populations.
We found that moose need cool, wet habitat to buffer the effects of rising temperatures, but that male and female moose choose different cooling habitat. We also found that autumn temperatures, as well as age, work together to drive mating in male moose. Better understanding the ecology of both sexes of moose will help ensure appropriate management actions.
Deer Elk Ecology Research Project
When mule deer and elk coexist, elk often come out on top for many reasons, including differences in how they move, their body size, and the types of plants they eat. In recent decades the population of mule deer in the Greater Little Mountain Area have remained relatively stagnant, while the population of elk remain stable or increasing—these opposing trajectories are what spurred the Deer-Elk Ecology Research (DEER) Project.
We found that elk and mule deer compete for space and resources; when mule deer and elk overlap, mule deer gain less fat, which affects their survival. We also found that mule deer had to balance multiple sources of risk from other ungulates as well as their predators, and that fawns that hide are more likely to survive early in life. Together, these findings help us understand how multiple ungulates and predators can coexist in an ecosystem.
Pronghorn Harvest Project
Pronghorn are a cherished species of big game and an iconic part of Wyoming and the West. Although many may view them as commonplace in Wyoming, they are an ecologically remarkable species with a suite of traits that differ drastically from any other species of wild game in North America. Given the unique ecology of pronghorn, can managers aim for ample opportunity for many hunters, while retaining the chance to harvest an impressive buck?
We found that pronghorn grow their horns in unique ways, and that bucks attain over 95% of peak horn size by 3 years of age, and reach peak horn size by 6. We also found that snow depth in the winter a buck is growing inside his mother’s womb determines how large his horns will grow for the rest of his life; deeper snow leads to more moisture and food for mother and a lifetime of larger horns for her son.
Harvest Records Project
Hunting is an important part of wildlife management, but there is concern over how harvest might affect the size of horns and antlers of ungulate species over time. This project evaluated how the size of horns of hunted bighorn sheep changed through times, and identified the mechanisms that caused change.
Among the 72 hunt areas we studied, horn size remained unchanged in 44, decreased in 19, and actually increased in 9. The researchers found evidence that all three mechanisms caused changes in horn size, depending on the hunt area in question. In fewer than half of hunt areas where horn size declined, evidence pointed to hunting as the cause of evolutionary change. In the others, nutrition and changing age structure appeared to be driving down horn size. In all, current harvest regimes in most hunt areas do not appear to be reducing horn size in bighorn sheep.
Snowy Range Moose Project
Moose have evolved to thrive in cold-weather environments of northern latitudes, but as moose distribution has expanded south in the last century, the warmer temperatures of these regions may be challenging their ability to manage heat stress. The Snowy Range Moose Project, completed in 2019, focused on how the thermal needs of moose at the southern end of their range and how they may be combatting rising temperatures behaviorally.
We found that moose select for bed sites that have cooler temperatures and are either moist or wet as compared to bed sites that were in areas that increased the risk of overheating during the day. As days got hotter, use of standing water and wet grounded bed sites increased. This project conclude that moose are behaviorally mitigating their risk of overheating by seeking out day beds that allow them to lose heat to the ground or the water they are in contact with.
Sierra Madre Elk Project
Widespread mortality of pine trees following the bark-beetle epidemic can change the ways wildlife and people interact with these formerly intact forest habitats. Elk, for example, rely on intact conifer forests for thermal refuge and escape from predation (e.g., natural predators and human hunters), but as beetle-killed trees fall, the subsequent changes to canopy cover and understory structure can alter forage abundance, thermal cover, and locomotive costs for elk. Behavioral responses of elk to changes in forest structure may, in turn, shift how people hunt them, affecting the way we manage this highly valued species and their habitats.
We found that elk typically avoid beetle-killed conifer habitat, instead choosing to spend their time in intact conifer forests and in grassy meadows. During the autumn hunting season, however elk selected for beetle-killed forests, perhaps as an escape tactic from hunters. GPS tracking of human hunters also showed that hunters were willing to follow elk into and use beetle-killed areas for hunting purposes, particularly when more elk were there.