It takes a tough scientist to study wolverines in crazy cold conditions, but the wolverines are even tougher.
Stanley, Idaho, is one of the colder areas of the lower 48 states in the U.S. In January, the average high temperature is 26 degrees Fahrenheit, with freezing temperatures that can drop as low 40 degrees below zero with wind chill. However, cold regions like this are ideal habitat for wolverines, which means the people who study them have to learn to survive there as well.
ÛÏI grew up in Seattle, where, you know, you were wet in the cold—but you don’t ever think of what it would be like to be in negative 40 degree weather. So preparing for that is probably my biggest challenge,Û said Blakeley Adkins, a wolverine technician for the Idaho Department of Fish and Game.
Her current research project looks at wolverine presence across Wyoming, Montana, Washington, and Idaho; these are the four states in contiguous U.S. with the highest wolverine populations. Prior research from biologists and wolverine specialists indicates that wolverines require deep snowpack that persists into spring for denning and caching food supplies. Adkins’ project is a presence/absence survey, which will be compared to models of wolverine dens coupled with mapping models generated in relation to projected future snow pack.
The study splits the four-state research area into 15 or 16 km grid cells. A total of 180 grids were picked at random, and teams like Adkins’, which includes two other researchers, install and manage motion-censored cameras to monitor their areas for wolverine presence. Adkins’ team covers 10 cells and works out of Stanley and Ketchum, Idaho.
ÛÏWe have bait hanging on a tree with stinky lures to try and attract wolverines into the area: To not only get their photos but also to try and collect hair on gum brushes that we have set up around the tree where we have bait on it,Û Adkins explained. ÛÏWe’ll be able to tell who the wolverine is if we’re able to collect that hair and if they’re related to other wolverines we get hair from.Û
The researchers set up a game camera and sticky brushes that are designed to capture hair. To entice the wolverines to the area, a hindquarter of elk is hung from a tree branch and a scent lure made from castor and skunk odor is left in the area.
ÛÏSmells pretty great,Û Adkins joked.
The sites, Adkins said, would look a little peculiar to someone who just stumbled upon them, but to her, the craziest part of this work is the cold. This research is only carried out in winter, when hunting and scavenging opportunities for wolverines are sparse, and between the temperatures and the remote location of the sites, work can be challenging.
ÛÏOne of our sites is about a three-hour snowmobile ride,Û said Adkins. ÛÏAnother site is about a five-mile ski up a road.Û
As a consequence, exposure is her biggest concern when accessing sites. åÊAlthough a below -40 day is rare, minus-20 åÊdays are more common, and bundling up for fieldwork is a necessity.
ÛÏYou feel it in your face, your nose, you feel it everywhere! And snowmobiling in that too Û_ I think we’ve all come back with white spots or even black spots on our faces,Û she said.
On one recent occasion, Adkins and a coworker snapped the zippers off their coats because the cold had made the metal so brittle. When her coworker used his Leatherman knife to tighten a wire that was holding up bait, his handle snapped in half.
Most of Adkins’ current work is carried out during the daytime, and she and her team have the option of attempting to time visits on days where the weather is least extreme. In previous wolverine studies, she hasn’t always had this luxury.
Working on a Montana study of the impacts of recreation on wolverine behavior with Dr. Kimberly Heinemeyer, Adkins helped to trap live animals and tag them for tracking. In these cases, because a live animal was involved, the researchers had to leave immediately to visit the sites as soon as a trap triggered, regardless of weather conditions.
ÛÏSometimes, you’d be out there in the middle of the night in the cold for six hours, not really moving around that much, just waiting for that animal to recover,Û Adkins recalled.
Working in the cold with these hardy animals hasn’t deterred Adkins’ interest in them, though. If anything, it has heightened the respect she feels for them. She is impressed by their adaptations to survive in the cold: A dense, thick coat and broad paws that allow them to travel over snow easily. She also admires their ability to travel long distances. A male wolverine’s territory is described as around 500 square miles in most literature. Adkins has reason to believe they can travel even further.
ÛÏA few years ago, we collared one wolverine, Û÷Duke,’ out of Stanley,Û she said, ÛÏand he travelled 1,000 square miles across the Sawtooth (Mountains), which are pretty large, substantial mountains Û_ that’s pretty neat.Û
She also admires their tenacity. Wolverines have an anecdotal reputation for being aggressive, but Adkins thinks the reputation is undeserved.
ÛÏI’ve had people ask me how many times I’ve been attacked, (and I say), Û÷Oh never!’Û
Her suspicion is that this perception may relate to how rarely people tend to encounter wolverines in the wild. Because of their large home ranges and avoidance of populated areas, spotting a wolverine in Idaho is uncommon. Adkins suggested the reputation also may relate to wolverines’ fearless behavior when trapped.
ÛÏIf you have them in trap and you’re trying to get at them, they’ll lunge at you and claw at you and they don’t just sit there and back away from you. They confront you, if they’re upset. I respect that.Û
Adkins has been outsmarted by wolverines. On the recreation project, she had to anesthetize wolverines to place tracking collars on them. The anesthetic is typically injected into the hindquarter, and wolverines that have been trapped before seem to remember this.
ÛÏ(Collaring) is hard Û_ and even harder in the dark, which it typically is, and in the cold. Your drug freezes, and you’re having to stay still, and they’re really smart. If they’ve been jabbed before Û_ they’ll just stare at you and face forward. They’re like, Û÷I know if I turn around you’re gonna’ jab me again.’Û
On another occasion, conducting research in Alberta, Canada, Adkins and a partner continually returned to a trap to find the bait missing but the trap empty of any wolverines. A game camera placed at the site revealed that a wolverine, who probably weighed roughly 35 pounds, had discovered a way to escape from the trap by lifting the 100-plus pound lid by pressing against it with her shoulders.
ÛÏI kind of like that too—when they outsmart you,Û said Adkins. ÛÏ(It) makes your job a little more interesting.Û
Robust though individual wolverines are, there is concern that their populations may be at risk of decline if climate change leads to alterations in snowpack distribution and persistence. åÊWolverines in the contiguous U.S. have been proposed (and declined) for threatened status under the Endangered Species Act. In 2017, wolverines will be proposed for this status again. Research such as the studies Adkins carries out will help to improve understanding of the habitat needs of this elusive species, and hopefully inform decisions about how best to ensure their continued survival.
Elise Mulder is Earthzine’s senior science writer and mud pie maker extraordinaire. Follow her on Twitter @mountainlark.