The wolverine is the largest member of the weasel family. It has a circumpolar distribution and is quickly gaining recognition as an icon of the Canadian wilderness. Ferocious and unstoppable, wolverines have a reputation of being ravenous killing machines that are unfazed by even the most vicious opponents.
Historically, the wolverine has had to battle pressure from trapping and habitat fragmentation, the result of an always increasing human footprint. These pressures have led to declines in wolverine populations worldwide.
In Canada, wolverines are managed as an eastern and western population. The eastern population is listed federally as endangered. The western population is considered a species of special concern, while specifically in British Columbia, it’s considered blue-listed, which is similar to the federal threatened status.
As if that wern’t enough, the wolverine is now facing a new challenge: climate change. The wolverine feels the stress of climate change more in southern populations like in the continental United States
In the US, the wolverine’s historical range has been reduced substantially. Currently, populations can only be found in the Pacific Northwest.
To understand the latest plight of the wolverine, one needs to understand the connection between snow and wolverines. Each February, females will den in snow caves, and give birth to offspring called kits. These dens are dug eight to 10 feet into the snow pack. This depth is important as snow insulates, keeping the kits cozy. Snow pack is also important for the protection of the kits from predators when the mother is off scavenging for food.
Wolverines have yet another relationship with snow. These scavengers rely heavily on carcasses of other mammals that fall victim to winter. Using their superb sense of smell, a wolverine can dig out victims, and use their intimidating jaw force to crunch through frozen muscles and split open bones.
In other cases, carcasses that have been buried in snow remain frozen until the snow melts. At this point, these frozen buffets are sought after by a variety of other scavengers, including hungry grizzly bears, who are just awakening from hibernation. While significantly outsized by these bruins, wolverines have been documented holding ground, and even fending off bears from carcasses.
It seems to be undeniable that the planet is getting warmer. This means that more precipitation is falling as rain instead of snow, resulting in a shrinking snow pack. This becomes increasingly important for the most southerly distributed wolverines.
Areas that once had abundant levels of snow are now experiencing a diminishing snowpack. Abundant snow levels are now only found higher up in the mountains, or further north. The intimate connection between wolverine and snow is forcing them to move away from the historical range into smaller and smaller spaces. In the US, this is resulting in wolverines being squeezed out almost completely.
Although estimates of wolverine populations in the US are likely less than a thousand, conservation groups are struggling to get their federal government to officially recognize the species as threatened. As in Canada, a federally recognized species in the US is afforded special protection.
Global warming is a reality and humans are the primary cause. The wolverine is and will continue to feel the effects of global warming until we change our habits and stop contributing to the warming.
— Jeff Wilson and Will Cameron,
Second year Recreation, Fish and Wildlife students at Castlegar’s Selkirk College.