I have never seen a wolverine in the wild. I’m impressed by anyone who has seen one, though. They likely trekked through some challenging terrain with persistent snow in a remote part of some northern clime to have encountered one. I only know a few biologists who have been fortunate enough to see one or even signs of this circumpolar carnivoran.
The few wolverines that I have seen were all under human care at North American zoos and in zoos they are rare. As the education advisor for wolverines held in member institutions of the Association of Zoos and Aquariums, I try to disseminate information on these large mustelids through channels that will benefit conservation efforts for the species.
Although some large populations exist in North America and North Asia, the European wolverine was extirpated through much of its southern range and is considered fairly rare. The species as a whole retains the status of Least Concerned on the IUCN Red List, but that may change.
Threats to the wolverine include continued over-exploitation of habitat resources, predator control campaigns and over-hunting and trapping. The biggest threat may be global warming, which will most likely reduce the range of the wolverine worldwide.
Wolverines need expansive habitat and where they do exist their densities are low and populations are fairly isolated. Like bears they are fairly opportunistic foragers, feeding on a range of game ungulates and carrion, but they don’t hibernate. They thrive on the snow and they need it and use it to survive.
In a recent article published in the Journal of Mammalogy, Robert Inman of the Wildlife Conservation Society and colleagues assert that wolverines use cold, snow-covered structured chambers like crevices and those created by the rugged terrain of mountainous areas to cache food and protect it from other scavengers, insects and bacteria.
“People don’t normally think of insects and microbes as being in competition for food with wolverines,” said lead author Robert Inman of the Wildlife Conservation Society’s North America Program. “But in fact, bacteria will devour an unprotected food source if that source is available.”
Ultimately, their reproductive potential is influenced by early litter loss without cached food supplies.
Inman said, “Understanding why and how wolverines exist where they do and the various adaptations they have evolved to eke out a living will better inform population management strategies and conservation of the species.“
The authors further suggest that a more complete understanding of how and why wolverines use snow pack the ways they do is critical to understanding how climate change will impact survival and reproductive rates.
“Shedding light on the specific mechanism of how climate will affect wolverines is important in order to know what to do to help them hold on,” said WCS’s North America Program Director, Jodi Hilty.
One of the best resources for information on the natural history and conservation of the wolverine is the The Wolverine Foundation.
Notes on the wolverine:
Wolverines like humans, raccoons, and bears walk with a plantigrade foot posture. Their powerful jaw musculature and dentition permits them to feed on bones and frozen foodstuffs such as winter-killed ungulates. Powerful for their size the wolverines are the largest of the terrestrial mustelids. They can climb trees readily and swim well, but are neither arboreal or aquatic carnivores. Similar to ursids of North America, wolverines rely on olfaction, but they also have a keen sense of sight and hearing. They are remarkable animals that face an uncertain future in the face of global climate change.