Climate Change Impacts on Winter Adaptations in Terrestrial Mammals

Climate change is reshaping winter environments across the globe, altering snow cover duration, thermal regimes and photoperiod cues that terrestrial mammals have relied on for millennia. Key winter adaptations—seasonal coat colour moulting, hibernation and use of the subnivium—are finely tuned to historical patterns of snowfall and temperature. As winters shorten and warm, mismatches between coat colour and background snow cover increase predation risk, while unstable subnivean refugia expose small mammals to thermal stress. Rising winter temperatures may also disrupt the timing and depth of torpor bouts in hibernators, leading to higher energy expenditure and reduced survival. Together, these changes are driving shifts in species’ distributions, altering interspecific interactions and challenging the resilience of winter specialists.

Research from Nature Portfolio

Recent studies have shown that subspecies of small mustelids with seasonal white pelage suffer higher mortality when snow cover declines. Field data reveal a decrease in the proportion of white‐coated individuals as the number of snow‐covered days falls, indicating strong selective predation pressure. Experimental placement of white and brown models against contrasting backgrounds confirmed that contrasting phenotypes face elevated detection rates by predators. Limited plasticity in the timing and extent of winter moult means that colour‐mismatch mortality is likely to increase, foreshadowing range contractions and shifts in geographic distribution under continued warming.

Climate Change Impacts on Winter Adaptations in Terrestrial Mammals publication trend

The graph below shows the total number of articles in climate change impacts on winter adaptations in terrestrial mammals across all publications each year (not limited to Nature Index journals).

Technical terms

Camouflage mismatch: A discrepancy between an animal’s seasonal fur or feather colour and the prevailing background, increasing visibility to predators.

Phenological mismatch: A decoupling of the timing of biological events (such as moult or hibernation) from historical environmental cues, leading to maladaptive outcomes.

Torpor: A reversible state of reduced metabolic rate and lowered body temperature used by some mammals to conserve energy during cold periods.

Subnivium: The microclimate beneath the snowpack that provides thermal insulation and protection for small mammals during winter.

References

1. Function and underlying mechanisms of seasonal colour moulting in mammals and birds: what keeps them changing in a warming world?. Biological Reviews (2018).
2. An experimental translocation identifies habitat features that buffer camouflage mismatch in snowshoe hares. Conservation Letters (2018).
3. Climate change is affecting mortality of weasels due to camouflage mismatch. Scientific Reports (2018).
4. Winter Conditions and Land Cover Structure the Subnivium, A Seasonal Refuge beneath the Snow. PLOS ONE (2015).
5. Snow-mediated plasticity does not prevent camouflage mismatch. Oecologia (2020).