Adaptions for Winter Survival
BY THE WILD BIRD CENTER , WEATHERFORD , TX
All small , warm-blooded creatures have difficulty maintaining their body temperatures in freezing weather , so many birds fly south for the winter . How do non-migrating chickadees manage to stay alive ?
To begin with , they have several physical adaptations – including dense plumage , shivering , and the ability to survive reduced body temperatures – that enable them to survive freezing conditions . Chickadees also adapt their behavior in several ways . They travel less in cold weather and are more likely to center their activity around rich food sources , such as feeders .
Thick Feathers Chickadees molt at the end of the summer , so they enter the winter with as much as 50 % more plumage than at any other time of the year , and their feathers are thicker and less worn . Chickadees have denser plumage than many other birds their size – a great adaptation for non-migrating birds . Chickadees also control the contour of their feathers , and when they are cold , they fluff them up to increase the thickness of their insulation .
Finch
Shivering As the temperature drops , chickadees begin shivering to keep warm . The colder it gets , the more they shiver . But maintaining a normal body temperature requires a lot of energy , and on cold winter nights chickadees often go into a state of regulated hypothermia . They actually drop their body temperature by decreasing , not stopping , shivering in the pectoral muscles . They then regulate their lower body temperature with intermittent and reduced bursts of shivering .
Late to Bed , Early to Rise Long winter nights pose additional problems for chickadees – the fewer hours of daylight mean less time for foraging . To compensate for this , chickadees begin and end their foraging times at lower light levels during this time of year than at any other time . They also intensify their use of reliably stocked feeders , so that their reduced foraging time is well spent .
Woodpecker
Bird Feeders and Houses Can Help Two ornithologists at the University of Wisconsin studied banded populations of chickadees for over three years , comparing the survival rates of those that had access to sunflower seed feeders with those that depended solely on natural foods . They found that nearly twice as many of the chickadees