Protecting the Pacific Northwest’s Wolverines
Originally published by Mongabay
Wolverines are extremely solitary animals that purposefully avoid humans, so seeing one in the wild is typically a once-in-a-lifetime encounter.
This makes planning for their conservation very tricky.
“Three ways we can best support wolverines into the future are to connect large areas of habitat, close seasonal use areas to create disturbance-free zones, and actively manage their populations,” a new op-ed states.
This post is a commentary. The views expressed are those of the author, not necessarily Mongabay.
An iconic inhabitant of rugged mountains in western Canada, the wolverine (Gulo gulo) covers tens of kilometers per day, running over treacherous terrain in search of oft-dead meat. For many avid mountain adventurers, a mere glimpse of a wolverine can be a once-in-a-lifetime encounter — even wolverine experts recount tall tales of times they briefly saw a blur slinking away between alpine boulders and shrubbery. The lore surrounding this elusive carnivore is in fact representative of its shy personality. Wolverine are extremely solitary animals that purposefully avoid humans, making their conservation a delicate coexistence.
In the contiguous U.S., wolverines received protection under the Endangered Species Act in December 2023 after many years of legal wrangling. The status listing was based on years of science which identified habitat degradation and climate change as primary concerns for the small remaining population of an estimated 300 wolverines. This recent decision is an important reminder of the precarious state of wolverines and adds momentum to conservation initiatives for connected cross-border populations living in southern British Columbia and Alberta.
The situation for wolverines in Canada’s southern mountains is not quite this dire, but it’s heading in the same direction. Over the past decade, wolverine densities in the Canadian Rockies have declined by 39%. Even protected areas like Banff National Park aren’t an adequate haven for wolverines, partially due to increasing backcountry recreation. Just three groups per fortnight can drive a wolverine out of otherwise great habitat. In winter, mountain wolverines den in deep snow, sometimes in those same basins skiers dream of cutting a fresh line. Wolverine mothers are most vulnerable in the winter and early spring, and a single human encounter could cause them to abandon the den. The population in Banff has seen low recruitment over the past decade, meaning that mothers are having a hard time ensuring their young survive to adulthood. In pockets of habitat outside of parks, wolverine survival is even more difficult, as they have to contend with resource industries and motorized backcountry recreation such as snowmobiling and heli-skiing groups.
Increasingly, wildlife biology is becoming more computer-based, with less time spent handling or observing animals — likely a relief to wolverines. With advances in technology and computer modeling, biologists can learn about wolverines without bothering them much. One of the ways researchers collect data on wolverines is by hanging a frozen beaver carcass in a tree wrapped in barbed wire. When the wolverine climbs the trunk for the tasty treat, some of its hair gets snagged on the wire, which can be later collected for DNA analyses. Hundreds of hair samples collected over decades, from the 49th parallel up to Banff and Glacier national parks, give experts a better idea of how more than 125 wolverines move across the vast landscapes of the Columbia and Rocky Mountains.
However, research alone is insufficient. Wolverines require conservation action that preserves undisturbed habitat. The scale of habitat a single animal — not to mention a healthy population — needs to survive is significant. In the mountains, an adult male wolverine will spend most of its time in a home range of about 1,000 square kilometers (just larger than the city of Calgary), while younger members of the population can travel twice that distance in search of less competitive territory.
Wolverine ranges overlap a handful of management jurisdictions: provincial parks, national parks, Indigenous protected areas, and various provincially managed lands. This also makes effective management a challenge. While wolverines are listed as at-risk federally, there are yet to be coordinated habitat protections on the scale needed to reverse population declines. Provincial management plans in B.C. and Alberta have not been updated in decades, and trapping still occurs throughout most wolverine habitat.
Despite a lack of action, when it comes to mountain wolverines, there is no shortage of research and knowledge. Three ways we can best support wolverines into the future are to connect large areas of habitat, close seasonal use areas to create disturbance-free zones, and actively manage their populations. Supportive measures already in place include a temporary trapping ban on wolverines in southern interior B.C., and winter closures around den sites in Kokanee-Glacier Provincial Park. To help inform coordinated management, a team at Yellowstone to Yukon Conservation Initiative worked to create a broad-scale habitat map that spans central regions of the Columbia and Rocky Mountains. This tool shows where a deep spring snowpack is likely to persist into the future, and highlights areas of key wolverine habitat that could be candidates for protection.
Indigenous peoples have sustainably managed wolverine populations for millennia, and continue traditional trapping of wolverine for its luscious pelt. To many First Nations, Inuit, and Métis, the importance of wolverine is beyond material; the wolverine is respected for its strength, intelligence, and often plays the role of trickster in oral traditions. Yet, over the past two centuries, wolverines have been driven out of close to 40% of their historic range in North America by settlers. In some recently established Indigenous Protected and Conserved Areas (IPCAs), such as the Dene Tha’ First Nation’s Bistcho Lake, managers pair traditional ecological knowledge (TEK) and western science to steward wolverine populations. Dene K’éh Kusān IPCA, proposed on Kaska Dena territory in northern B.C., will protect vast mountain habitat home to wolverine and 15 other at-risk species.
Habitat protections help more than just wolverines; endangered southern mountain caribou also rely on vast undisturbed landscapes, and intact old growth forests contribute to climate resilience and a healthy water cycle. By protecting key areas, managers can meet conservation goals and provide much-needed space for wildlife to adapt in this changing world.
Citations:
Barrueto, M., Sawaya, M. A., & Clevenger, A. P. (2020). Low wolverine (Gulo gulo) density in a national park complex of the Canadian Rocky Mountains. Canadian Journal of Zoology, 98(5), 287–298. https://doi.org/10.1139/cjz-2019-0165
Barrueto, M., Forshner, A., Whittington, J., Clevenger, A. P., & Musiani, M. (2022). Protection status, human disturbance, snow cover and trapping drive density of a declining wolverine population in the Canadian Rocky Mountains. Scientific Reports, 12(1), 1–15. https://doi.org/10.1038/s41598-022-21499-4
Fisher, J. T., Murray, S., Barrueto, M., Carroll, K., Clevenger, A. P., Hausleitner, D., Harrower, W., Heim, N., Heinemeyer, K., Jacob, A. L., Jung, T. S., Kortello, A., Ladle, A., Long, R., MacKay, P., & Sawaya, M. A. (2022). Wolverines (Gulo gulo) in a changing landscape and warming climate: A decadal synthesis of global conservation ecology research. Global Ecology and Conservation, 34(December 2021). https://doi.org/10.1016/j.gecco.2022.e02019
Heim, N., Fisher, J. T., Clevenger, A., Paczkowski, J., & Volpe, J. (2017). Cumulative effects of climate and landscape change drive spatial distribution of Rocky Mountain wolverine ( Gulo gulo L.). Ecology and Evolution, 7(21), 8903–8914. https://doi.org/10.1002/ece3.3337
Heinemeyer, K., Squires, J., Hebblewhite, M., O’Keefe, J. J., Holbrook, J. D., & Copeland, J. (2019). Wolverines in winter: indirect habitat loss and functional responses to backcountry recreation. Ecosphere, 10(2). https://doi.org/10.1002/ecs2.2611
Kortello, A., Hausleitner, D., & Mowat, G. (2019). Mechanisms influencing the winter distribution of wolverine Gulo gulo luscus in the southern Columbia Mountains, Canada. Wildlife Biology, 2019(1). https://doi.org/10.2981/wlb.00480
Laliberte, A. S., & Ripple, W. J. (2004). Range contractions of North American carnivores and ungulates. BioScience, 54(2), 123–138. https://doi.org/10.1641/0006-3568(2004)054[0123:RCONAC]2.0.CO;2
Mowat, G., Clevenger, A. P., Kortello, A. D., Hausleitner, D., Barrueto, M., Smit, L., Lamb, C., DorsEy, B. J., & Ott, P. K. (2020). The sustainability of wolverine trapping mortality in southern Canada. Journal of Wildlife Management, 84(2), 213–226. https://doi.org/10.1002/jwmg.21787
Schepens, G., Pigeon, K., Loosen, A., Forshner, A., & Jacob, A. L. (2023). Synthesis of habitat models for management of wolverine (Gulo gulo): Identifying key habitat and snow refugia in the Columbia and Rocky Mountains, Canada. Global Ecology and Conservation, e02540. https://doi.org/10.1016/j.gecco.2023.e02540