On April 17, 2011, wolverine biologist Audrey Magoun was snow-shoeing through a narrow valley in the Wallowa Mountains of Oregon when a familiar inscription in the snow caught her attention: the scrawl of wolverine tracks, heading through the valley bottom and then uphill. Audrey was en route to one of several camera stations that she and her husband Pat Valkenburg had set up in the Eagle Cap Wilderness as part of a study co-sponsored by the Oregon Department of Fish and Game. After years of experience studying wolverines in Alaska, the couple had an instinct that the Wallowas might be good habitat, but the tracks were the first definite sign that the range was occupied. The tracks – which Audrey thought probably belonged to a male, because of the length of the stride – were also the first scientific confirmation of wolverines inhabiting Oregon. A few days later, when Audrey and Pat checked the cards in their cameras, they found that two different wolverines had visited the stations earlier in April. .
The presence of at least two animals indicated that the mountains might support resident, breeding wolverines, but the photos alone weren’t enough to prove this. Wolverines, as anyone who studies them knows, move around incessantly, and young males can disperse over long distances and hang out in regions that don’t necessarily support females. Determining the sex of the animals in the photos would yield important insight into what the two wolverines might be doing here – whether they were living in the area, defending territories, and raising kits, or whether they were simply hanging out until a territory opened up somewhere else.
Audrey and Pat returned to the camera station sites with backpacks full of gear and bait, with two-by-fours slung over their shoulders, odd contraptions of metal and plastic rods strapped to their packs, and a hardware store’s worth of nails, screws, screwdrivers, pliers, and drills stashed in separate ziploc bags. The initial stations had consisted of hanging bait and a camera and were rigged to simply document presence. The new stations that Audrey and Pat constructed resembled wolverine-scale jungle gyms, with a haunch of r0ad-killed deer dangling just above an apparatus that would encourage a wolverine to stand on its hind legs to reach the meal. On either side of the apparatus, Audrey painstakingly set a row of alligator clips, held open by another set of alligator clips, to snag hair for DNA. Then they left, hoping that the two wolverines would be habituated enough to return, and hungry or curious enough not to be bothered by the transformed stations.
Camera-traps’ utility in identifying individuals among species like tigers, which have unique stripe patterns, was recognized almost immediately when camera trapping began gaining popularity as a conservation research tool, about a decade ago. Researchers can’t visually ID most species to the individual, however, so camera stations are generally designed to document presence of a species in a given area, often with accompanying devices to snag hair for DNA samples, which can help calculate how many animals might be in a region.
Audrey, who has studied wolverines for decades and is constantly thinking about how to improve research methods, first realized that wolverines, like tigers, have unique markings that would allow an individual ID: their chest patches. But since a wolverine’s chest patch is not fully visible when a wolverine is doing normal wolverine activities on all fours, Audrey had to figure out how to induce the wolverines who visited the stations to stand up on their hind legs and display their full markings. In doing this, Audrey realized, they would also be giving a view of their entire undersides, which would allow researchers to determine sex, and reproductive status of females in the spring. By adding a set of hair snags to the station, Audrey had created a minimally-invasive tool for gathering a huge amount of information on an elusive and difficult-to-study species.
The two Wallowa wolverines did return to the stations. Both were male; Audrey christened them Stormy and Iceman. At the very end of the season, a third wolverine appeared on the cameras. The photos of this wolverine, Zed, were not as clear as those of Stormy and Iceman, but Audrey was pretty sure Zed was a male too. They hadn’t documented females, but they’d documented enough wolverines to excite Oregon’s wildlife world, and the project was funded for a second season. One of the big objectives for the 2011-2012 season was to document a female.
I’d been hearing about Audrey’s work for years, and I’d communicated with her via email; like anyone approaching a hero of one’s chosen field, I was timid and self-conscious about talking to her, although she was always very generous in responding to my questions. As my work in Mongolia went forward and it became increasingly clear that a collaring study would be too logistically complicated, camera-traps seemed like the best option for the work I wanted to do. But when I looked at the book that Audrey had published about the technique, the complex diagrams induced the kind of headache that I get when I try to visualize in the abstract some mechanical operation that is best learned hands-on. I overcame an extreme case of nerves and emailed her to ask if I could come out to Oregon in December of 2011 to join the study for a few weeks, so that I would know exactly what it took to run a camera-trap grid in Oregon – and, by extrapolation, what it would take to do something similar in Mongolia.
To my surprise and delight, she generously said yes, and on December 3rd I set out from Bozeman, Montana to join the project. Audrey had made it clear that I was headed to an unheated farmhouse without plumbing, to engage in heavy physical labor in a rigorous alpine environment. Nevertheless, I would have been less nervous if I’d been invited to high tea with the Queen of England at Buckingham Palace. It promised to be an interesting two weeks.