Wolverine reproductive success is almost entirely dependent on deep, persistent spring snowpack for denning. As climate change reduces mountain snowpack, wolverine reproduction is declining in key populations.
The welfare of wolverine cubs depends entirely on the persistence of deep snow. Premature den collapse kills cubs through exposure and maternal abandonment. Females who lose cubs to failed dens may not reproduce again that season, compounding population effects. The stress of inadequate denning conditions on mothers — increased vigilance, nest rebuilding, reduced foraging time — represents an indirect welfare burden. Unlike some species that can adapt habitat use, wolverines have no substitute for deep snow. This makes them among the most climate-vulnerable mammals in North America from both conservation and welfare perspectives.