Researcher with doe mule deer
Melia Devivo holds a deer's head while waiting for colleagues to bring a new radio collar for the research subject. A doctoral candidate at the University of Wyoming, she's part of a team that caught and collected data from 175 mule deer in western Wyoming in December. (Angus M. Thuermer Jr./WyoFile)

The second of two parts. Click here to see the first half of this report and the WyoFile video “When Mule Deer Fly” — Ed.

KEMMERER — Of the many wonders in Wyoming, the sight of a herd of animals migrating across the landscape is among the most precious.

Even a jaded driver negotiating hours of windshield sagebrush will marvel at a string of antelope marching single-file through an early winter storm. When 1,000 elk queue up to move down from the high country, their column becomes an organism itself, driven to wintering grounds by deep instincts.

Routine and predictable, such mass movements also are at risk. They’re blocked by developments, bisected by highways and upset by drought.

“These migrations are threatened,” says Matt Kauffman, a University of Wyoming professor who studies them. “Large migrations are dwindling across the globe. There is a focused conservation interest.”

Kauffman leads a branch of the university’s Wyoming Cooperative Fish and Wildlife Research Unit, and migrations make up much of its work. He also directs the Wyoming Migration Initiative, a coalition of researchers and mapmakers that tracks and documents the state’s many terrestrial migrations.

Animals migrate because they have to. Migrating wildlife earn rewards. “As plants grow, they’re particularly nutritious at some times, like in the spring when they first green up,” Kauffman says. Annual journeys take animals to prime forage when it is most nutritious.

But migrating animals can be disruptive. They cross property lines, political subdivisions and bureaucratic dominions. They damage fences, get in the way of zooming cars, eat crops and spread disease.

Migrations require an unbroken avenue, a route sometimes more than 100 miles long. Without such natural highways, wildlife can’t survive, or if they do, it’s only on altered terms.

Last December, a team from Kauffman’s unit took to the field in western Wyoming to continue five separate mule deer studies, each of which has a migration component. For a week the group of about 10 researchers rises before dawn to catch, collar, sample and release deer.

When they’re done, 175 mulies will continue their tenuous treks, transmitting information about where they travel. When circumstances change, the science may reveal how those changes affect the deer’s well-being.

Wyoming’s mule deer population has fallen to two-thirds of the Wyoming Game and Fish department’s objective, according to the latest estimates from that agency. While populations fluctuate naturally, some herds in the western part of the state haven’t rebounded from their last dip.

Spreading energy development, increasing traffic, human encroachment, drought and disease all might play a role. The picture looks discouraging to Kevin Monteith, an assistant research professor at Kauffman’s unit. Yet he holds out hope.

Pump jack landing
Pilot Mark Shelton lands a pair of deer near a pump jack, one of many that dots the winter range. Studies try to determine what effect energy development and other disturbances have on mule deer, their habitat and their migration habits. (Angus M. Thuermer Jr./WyoFile)

“What can be encouraging is some of the populations we have are still very robust,” he says. “As decisions are made, if we can have the best information, at least be informed, we can realistically say ‘this is likely what will happen.’”

After 15 years of following deer that spend the winter on the Pinedale Mesa, researchers have some clues as to what happened there. The mesa is a 15-mile long ridge that’s also the site of the Pinedale Anticline gas field. It’s the site of the first of the five studies.

Thousands of deer from the 28,000-strong Sublette Herd spend the winter among the mesa’s gullies, seeking shelter from biting wind and grazing on exposed plants. To give deer the best chance, most people are banned from this critical Bureau of Land Management winter range during the coldest months.

But gas-field activity continues year-round. Research that’s entering its 15th year began when development started on the anticline gas field. “That’s why they have a really good population estimate,” Kauffman says.

The Sublette Mule Deer Herd has seen a 20 percent decline, he says. But the portion that winters on the Pinedale Mesa has fared worse.

“The Pinedale Anticline has seen, at one point, a 50 percent decline,” he says. “It’s rebounded to a 40 percent decline.”

The ongoing study on the mesa carries the scholastic title “Behavioral and nutritional response of mule deer to development on the Pinedale Anticline.” In other words, it will evaluate whether mule deer that contend with well-pad disturbance lose fat faster than others.

Radio-collar data will reveal which deer surrender their instincts and venture closer to intrusions like gas wells. Information from their twice-annual capture will describe their condition before and after the cold months.

There are other insights researchers may gain. Samantha Dwinnell, a graduate student at the university and a leader of the field team, seeks to build on work by researcher Hall Sawyer. A biologist with Western Ecosystems Technologies and also an associate professor at the university, his work has been instrumental in revealing western Wyoming mule deer secrets.

“We know from Hall’s work that these animals avoid energy development,” Dwinnell says. Yet some mule deer are seen near well pads.

“Animals in those areas are potentially in poorer nutritional condition,” she says. They take risks to forage in those areas. “They need to do it to ensure survival.”

Boiled down, research seeks to understand the relationship between nutrition, habitat and mule deer behavior, Dwinnell says. Energy development and other intrusions may have an effect on the nutrition and condition of mule deer. Deer may subsequently modify their behavior to try to overcome the effects of development.

In the second study, the capture and recapture of deer from the Wyoming Range Herd will help answer a simple question — how many deer can the summer and winter habitat support. The herd has numbered as high as 50,000, but today has only 33,000 members.

The population hasn’t recovered to levels seen in the 1980s. The Wyoming Range Mule Deer Project seeks to measure the “nutritional carrying capacity” of the herd’s habitat.

weigh deer skyline
A blindfolded mule deer perks up its ears as its capture ends at the research team’s scale. Gathering such information twice a year enables biologists to figure out effects of long-term drought and other factors on the animals’ health. (Angus M. Thuermer Jr./WyoFile)
A blindfolded mule deer perks up its ears as its capture ends at the research team’s scale. Gathering such information twice a year enables biologists to figure out effects of long-term drought and other factors on the animals’ health. (Angus M. Thuermer Jr./WyoFile)

The U.S. Geological Survey helps fund the third study, also involving Wyoming Range deer. It would answer questions about how long-term drought affects mulies.

“We’re starting to see the sort of signal of drought on big game in Wyoming,” Kauffman says. “We study the influence of drought on mule deer and benefits of migration.”

Drought is easily understood in arid Wyoming. But in a state heavily dependent on energy development, the related concept of human-caused climate change is not embraced.

“If you say you’re studying climate change in mule deer, the politics around climate change and misunderstanding muddies the discussion,” Kauffman says. “We often refer to it as drought as opposed to climate change.

“We’re studying what is happening right now — the drought intensity the deer are experiencing,” he says. “Leave it to somebody else to evaluate why we’re seeing more frequent drought. We’re not addressing those questions. We’re addressing ‘What does it mean for mule deer?’”

The recapturing of deer twice a year moves the Wyoming Range and Pinedale Anticline studies beyond the simple “collar-and-foller” characterization of some wildlife studies. All the data, from weight to amount of fat and so on reveals how individual animals fare.

“In March, we’ll capture them and they’ll be all skin and bones,” Kauffman says. In fall, researchers find out how much weight each doe has gained. Tracking information from the radio collar reveals where the animals fattened up.

The same information from the winter also is important. “Does an animal who has to contend with energy development lose fat more quickly?” Kauffman asks.

The capture team’s two other studies focus long-term on significant migrations. Researcher Sawyer discovered one — the now-famous 150-mile Red Desert-to-Hoback route that’s the longest documented mule deer migration in the world.

Some 4,000 to 5,000 deer make the trek twice annually. Mapping the route already has reaped rewards by highlighting a critical bottleneck. Many of the deer traverse a 400-meter-wide gap between homes and the outlet of Fremont Lake.

There, subdivisions, recreation and traffic threaten to cut the route. A private 364-acre parcel was a migration keystone — and it was on the market. Acting on the research, the Conservation Fund secured a purchase contract for the parcel. In September, 2014, the group launched a $2.1 million campaign to buy the land.

“That migration has a lot more to teach us about mule deer,” Kauffman says, “how they migrate, how they interact with the harshness of winters, the harshness of the summers.” Researchers might learn why the timing of migrations fluctuates wildly.

“Sometimes they come down from the high country, finally getting to the Red Desert in February,” Kauffman says, when human snowbirds have long gone from Wyoming. “Then (the deer) turn around and leave the next month.”

The fifth study will track the Baggs Mule Deer Herd in southern Wyoming. It migrates between the Sierra Madre Mountains and the Atlantic Rim. BLM land on the Atlantic Rim, part of the Great Divide Basin, is targeted for natural gas development, Kauffman says.

“Monitoring started prior to major expansion of the energy development,” he said. “We’ll have GPS collar data before and after the development.”

Kauffman tweets one already established finding to his cyber audience during the capture week. “Baggs #wyodeer speed up and stopover less in developed areas reducing the benefit of migration,” he writes. The tweet links to an 11-page scientific paper.

Melia researches
Devivo uses her cell phone to quickly discover how to reduce frothing in blood samples — employ glass vials instead of plastic ones. Teammate Alex May discusses the issue. Each evening some samples have to be processed, even in hotel rooms. (Angus M. Thuermer Jr./WyoFile)

University researchers give wildlife and habitat managers valuable information. “Game and Fish often refer to the co-op unit as their de facto research arm,” Kauffman says. “When Game and Fish is struggling to figure out what is going on with deer in the Wyoming Range … they come to us first, typically.”

Independence from the Game and Fish helps reduce potential conflict-of-interest charges from the public, he says. “Game and Fish can point to [research] as a University of Wyoming study. It creates a nice separation between research and management.”

There’s a challenging element to the relationship however. “The co-op unit essentially has no budget for research,” Kauffman says.

The U.S Geological Survey pays three salaries and a fourth is funded through grants and foundation support.

“That’s essentially it,” he says. “The Game and Fish Department, the cooperator, provides $40,000 to our operating budget. That sort of keeps the coffee machines on.”

When researchers launch a study, they have to raise funds to conduct it.

“All the projects come from outside sources, including the Game and Fish,” he says. Other contributors include the sportsmen’s groups Muley Fanatic Foundation and Rocky Mountain Elk Foundation, the BLM, the Wyoming Governor’s Big Game License Coalition, the Wyoming Wildlife and Natural Resource Trust Fund and private foundations, among others. It is, Kauffman says, “a long list of funders.”

Game and Fish used to provide $180,000 a year to fish research, and the same amount for big game. Budget cuts have hurt. Today that sum is down to $150,000.

“Typically we raise enough to start the project in the first year and we’re raising money every year after that to keep it going,” Kauffman says. His ungulate branch is one of three parts of the co-op unit. Another co-op arm studies fish, the third birds, small mammals, reptiles and amphibians. Collectively they raise $1 million to $1.5 million a year.

Game and Fish money often launches studies. “Once the co-op unit and Game and Fish get together, then it’s fairly straightforward to get other funders to consider coming on board,” Kauffman says. “We’re often matching Game and Fish funds four-to-one.”

The contributions are essential, Monteith says. “Without all of those folks stepping up we couldn’t do our jobs.”

Christmas in Diamondville
Field work takes team members away from their homes for a week, last year just before Christmas. They move a mound of gear each morning and evening, usually before dawn and after dusk. (Angus M. Thuermer Jr./WyoFile)

It is lunchtime in the field near LaBarge and capture crewmembers stand while eating chili that’s offered from a pickup tailgate. They are waiting for pilot Mark Shelton and “mugger” Donnie Wackerman to bring in more deer. Their aerial net gunning is the safest way to catch mulies, and it allows the animals to be immediately released without the lingering effects of sedation.

Work lasts until dusk forces the airship down. One evening, when the team moves south to Kemmerer, Shelton sets the bird down in the parking lot of the Best Western motel for the team’s one-night stopover.

In the heart of Wyoming’s energy boiler, Kemmerer is home to the 13,400 acre Kemmerer coal mine and PacifiCorp’s nearby coal-fired Naughton power plant. Energy workers and consultants check in and out of the motel regularly. Dually pickups with chrome trim dot the motel lot.

Yet Shelton’s ride is the sweetest one here. By nightfall, the Robinson R44 helicopter is cloaked in a trim-fitting cape and rotor sock, its core electronics fed by an extension cord that runs to a nearby light pole.

While it rests, some of the team can’t. They’ve got a date at the Muley Fanatic Foundation’s annual fundraising banquet in Green River, 71 miles away. The sportsman’s group is a major funder of the Wyoming Range study.

Some members of the team dress up for the ball. Others, who won’t go, move a small freezer, a centrifuge and other lab gear into a room. They’ll eat pizza, spin blood vials in the centrifuge and use a pipette to separate some samples into smaller containers for various tests. It will be a long day. 

“There’s no doubt they are really taxing — sleep deprivation to the max,” Dwinnell says of the work hours. “Regardless of all that, it’s still really fun being out.”

A mule deer is set free to rejoin its herd near Cokeville. Researchers hope the information they gain from studies will preserve one of Wyomng's natural treasures. (Angus M. Thuermer Jr./WyoFile)
A mule deer is set free to rejoin its herd near Cokeville. Researchers hope the information they gain from studies will preserve one of Wyomng’s natural treasures. (Angus M. Thuermer Jr./WyoFile)
A mule deer is set free to rejoin its herd near Cokeville. Researchers hope the information they gain from studies will preserve one of Wyomng’s natural treasures. (Angus M. Thuermer Jr./WyoFile)

In a field that’s too often dominated by heavily footnoted scientific papers that use multisyllabic words, Kauffman and his colleagues are changing things. Twitter, Facebook, websites and videos are starting to spread the word in a way people understand.

“The public can relate to migration and is impressed … fascinated by these movements,” Kauffman says. “All of that is happening in the little town of Wyoming where you can react with the rancher who owns that piece of land (and) Joe Mulie sportsman. The fact that you can bring research into that whole context is really rewarding.”

The payoff is real, too. Studies help determine, for example, where best to locate highway wildlife underpasses and overpasses. Those who keep track estimate cars and trucks wipe out about 3,500 mule deer a year on Wyoming’s highways, Kauffman says. Just down the road from the Best Western, 14,000 mule deer use seven underpasses in Nugget Canyon every fall.

Positive results from research are what inspire Monteith, who first came to know deer at his childhood dinner table in South Dakota. “We couldn’t afford to buy meat from the grocery store,” he says. Now he’s giving back.

“Without having good data about what’s going on, it’s difficult to make wise decisions,” he says. “To me it’s obvious, we can’t make informed decisions unless we have the information in hand.”

Cokeville game warden Neil Hymas patrols the winter range where many of the study deer roam. “To anybody who appreciates and understands wildlife, this is a treasure,” he says while looking over the rolling hills.

“These are pretty complex critters,” Hymas says. “This team will solve most of the mysteries before they’re done, I’m pretty sure of it.” 

Only with the help of the mule deer mothers. Deer No. 42, the “pretty small gal,” that has given researchers a file folder of data, eventually gets to rejoin her family.

It’s late in the day when she is caught. During her 10-minute processing the sky’s color turns cold, the helicopter’s chop has faded.

Kauffman has the last hands on her, whisking off her blindfold as her hobbles are freed. In an instant she’s part of the landscape again, bounding over sagebrush on a mission to survive, breed and, researchers hope, teach.

Angus M. Thuermer Jr. is the natural resources reporter for WyoFile. He is a veteran Wyoming reporter and editor with more than 35 years experience in Wyoming. Contact him at or (307)...

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