Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage.
As duration of snow cover decreases owing to climate change, species undergoing seasonal colour moults can become colour mismatched with their background. The immediate adaptive solution to this mismatch is phenotypic plasticity, either in phenology of seasonal colour moults or in behaviours that reduce mismatch or its consequences. We observed nearly 200 snowshoe hares across a wide range of snow conditions and two study sites in Montana, USA, and found minimal plasticity in response to mismatch between coat colour and background. We found that moult phenology varied between study sites, likely due to differences in photoperiod and climate, but was largely fixed within study sites with only minimal plasticity to snow conditions during the spring white-to-brown moult. We also found no evidence that hares modify their behaviour in response to colour mismatch. Hiding and fleeing behaviours and resting spot preference of hares were more affected by variables related to season, site and concealment by vegetation, than by colour mismatch. We conclude that plasticity in moult phenology and behaviours in snowshoe hares is insufficient for adaptation to camouflage mismatch, suggesting that any future adaptation to climate change will require natural selection on moult phenology or behaviour.
['Zimova|Marketa|M|', 'Mills|L Scott|LS|', 'Lukacs|Paul M|PM|', 'Mitchell|Michael S|MS|']
D000222:Adaptation, Physiological D000818:Animals D057231:Climate Change D034621:Hares D018978:Molting D009009:Montana D012621:Seasons D012880:Skin Pigmentation D012914:Snow
snowshoe hare phenotypic plasticity climate change phenology camouflage mismatch crypsis