The Absaroka Beartooth Project: Captures

The Absaroka-Beartooth Project report was published two weeks ago, the culmination of a five year project to investigate the status of wolverines in and around Yellowstone National Park. The report could be summarized in a straightforward  way, but as I read it, I realized that a laundry list of statistics wouldn’t do justice to the project’s many facets. I’ve been involved with this project, off and on, since 2006, and I thought it would be more interesting to provide a narrative for each segment of the project. I’m starting with the very basic story of the wolverines that were captured over the course of five years, and what those captures tell us about the status of wolverines in Yellowstone.

Yellowstone National Park is the wellspring of the idea of sacred wilderness in modern American consciousness. Our first national park, correctly or incorrectly, is perceived as a pristine stronghold of our most spectacular and intriguing species, which are supposedly free to function in the absence of human interference, and there to teach us what unfettered nature looks like. So it made sense, following the success of the Glacier National Park wolverine study, that the  investigation of wolverine status in Yellowstone was the next priority for a creature emblematic of the wild.  No one knew anything about wolverines in  Yellowstone; aside from sporadic sighting reports, data on the species was non-existent. The park and its surrounding ranges – hypothetically ideal habitat – were expected to provide one more piece in the puzzle of wolverine status in the US Rockies.

In 2003, the wolverine had been turned down for listing, for the second time, due to lack of data. The Glacier project began that same year,  aiming to fill some of the gaps that prevented the US Fish and Wildlife Service from determining  the wolverine’s situation. By 2005, the Glacier Project was yielding solid information and environmental groups were suing the government to reconsider the 2003 decision. The Absaroka-Beartooth Project began that winter with an initial season of live-trapping. The park was the core of the investigation, but the project extended beyond the park boundaries to encompass the Absaroka mountains and the Beartooth plateau to the east, northeast, and southeast. Complimenting on-going work by the Wildlife Conservation Society in the Montana ranges west of Yellowstone, the project established live-traps for wolverines in locations across the park and its eastern borders.

The Absaroka-Beartooth Wolverine Project encompassed ranges in and to the east, northeast, and southeast of Yellowstone.

In March of 2006, I arrived in Sunlight Basin, a spectacular valley in the eastern Absarokas, to meet with Jason Wilmot and his wife Kate, who were stationed there to monitor traps through the winter and spring.  I’d come to discuss my upcoming summer research on wolves in Wyoming, but the conversation quickly turned to wolverines. Within 12 hours of meeting the Wilmots, I was traipsing up a steep slope, knee-deep in snow, carrying a duffel bag containing a skinned frozen beaver, and listening to Jason as he talked about all the things that made wolverines the most awesome animals on earth. Key among its attributes, for me, was the coincidental information that there was an unstudied population in Mongolia, where – it so happened – I had spent two years as a Peace Corps environmental volunteer. We reached a log-box trap buried in snow, and while I examined a small plaque that stated that the trap and its contents were part of a research project and should be respectfully left in peace, Jason attached the beaver carcass to the back of the trap in hopes that a wolverine would soon remove it.

He and Kate waited through the entire spring, but the beavers in all of the Sunlight traps remained untouched by gulo-kind. While the thought of Mongolian wolverines lodged at the back of my mind and began to germinate into what would become, three years later, a full-fledged project of its own, the Absaroka-Beartooth Project captured wolverines north of the park, and south of the park, but the rugged mountains within the park boundaries and just to the east seemed strangely devoid of the West’s most notorious mountaineer.

By summer of 2006, when I returned to Wyoming to begin my summer research on wolves, the Absaroka Beartooth Project was monitoring two male wolverines, M1 and M2. M1 made his home north of the park; he’d been captured twice over the course of the winter. M2 was captured, once,  in the southern part of the park. Researchers refer to ‘trap nights’ as the number of nights a single trap is open and baited.  The three captures of M1 and M2 represented the fruit of 1831 trap nights in 2006, for an average of one capture every 610 trap nights. In contrast, the Glacier project in its first year captured six wolverines – three males and three females – with an average of one capture every 12 trap nights.

If these numbers fazed him, Jason didn’t give any indication of concern over the course of my wolf research in summer 2006; he continued to talk about wolverines with so much enthusiasm that I became more and more intrigued. In August of 2006, tired of the squabbling over wolves and hoping for a chance to appreciate a species free of the weight of centuries of symbolic feuding, I joined an Absaroka Beartooth project expedition to investigate a cluster of GPS points from M2’s collar. By now, M2 was hanging out south of the park, in some of the most inaccessible territory in the lower 48, and it took two days to reach the site. At dusk on the first night out, a wolverine came into our camp. It wasn’t an instrumented animal, which meant that it was an entirely new wolverine. We were able to extract a viable hair from a snowfield, which later matched DNA from male M4, captured by the project months later in March of 2007. The project instrumented him and located him once in a flight following the capture, but he subsequently disappeared. We still don’t know if his transmitter failed, if he took off for Colorado or Utah, or if he died.

A month before M4 was captured, M1, the project’s first male, was legally killed by a Montana trapper. Then, the week before M4 was captured, the project caught a small juvenile female in the Absarokas north of the park, within M1’s territory. This wolverine was tagged F3, and she is probably M1’s daughter. A female wolverine was legally killed in the same region at the same time; this was possibly F3’s mother, and her death meant that F3 could take over the now-vacant territory. F3 became the center of the project’s hope and attention, a young female just coming into her reproductive years. These four wolverines – three males, one dead and one vanished, and one young female who, despite our hopes, remained stubbornly single and kit-less – were the entire captured population of the project’s five years. Over the course of the project, they were caught seven times – M1 was caught twice, F3 three times. All told, the average capture rate was one wolverine every 750 trap nights.

The enormous effort required to document such a scant population suggested something unexpected: Yellowstone National Park and its eastern borders – huge, rugged country that should have been ideal habitat – lacked a substantial population of wolverines. They simply weren’t there. Yellowstone, the great emblem of all things wild, was apparently missing the wildest creature of all.