Wolverine denning success depends on deep, stable snowpack that is disappearing with climate change, threatening reproductive success across large portions of their range.
Denning wolverine females and their helpless kits are acutely vulnerable to snowpack instability. A den that collapses due to warm weather or rain-on-snow events exposes kits to lethal temperatures and disrupts the nursing period. Mothers whose dens fail may abandon kits or attempt relocation, with high kit mortality in either case. The progressive loss of reliable denning snowpack across the range is a slow-motion welfare crisis affecting reproductive success in generation after generation. Trapping regulations should account for denning periods to avoid disturbing nesting females.