Wolverines are superbly adapted to harsh winter conditions but face intensifying pressure from climate change, which is eliminating the snowpack that their denning and food caching strategies depend on.
Wolverine winter welfare is shaped by an exquisite evolutionary specialization to deep-snow environments that is now becoming a vulnerability in a warming climate. The snow tunnel dens that female wolverines excavate for birth and early kit development are not simply a behavioral preference — they provide thermal stability that protects developing kits from the lethal temperature swings of early spring, when surface temperatures fluctuate dramatically while deep snow maintains near-constant temperatures. Without adequate persistent spring snowpack, denning wolverines cannot provide the thermal buffer their kits require, and breeding failure rates increase directly with declining snowpack depth. This is a welfare crisis that operates at the intersection of individual reproductive welfare — failed breeding is a welfare-relevant outcome for animals that make significant energetic investments in reproduction — and population viability. The wolverine response illustrates why climate action is an animal welfare issue: no amount of local habitat management can compensate for the loss of persistent snowpack that wolverine reproductive welfare requires. Reducing greenhouse gas emissions is, at this scale, the most welfare-effective action available.