Over the coming weeks, white-tailed deer will be shedding their brown/grey winter coats or hair, which will be replaced by a summer coat with more reddish coloration.
This process, and the resulting patchiness in a deer’s coat, can be mistaken by observers as a sign of illness or injury, but is a natural process that helps deer thermoregulate throughout the seasons. The reverse process (deer shedding their summer coat for their winter one) typically occurs in early to mid-September.
A white-tailed deer’s winter coat is comprised of dense, hollow hairs that provide insulation against cold winter temperatures and snow. This coat is so well adapted to hold in a deer’s body heat that snow often accumulates on deer while they are bedded during winter storms.
The summer coat, on the other hand, is comprised of thin, lighter hairs that are meant to help deer stay cool during the warm summer months. The change in dark to lighter hair coloration also likely helps deer absorb heat from the sun during the winter and reflect it in summer.
Deer observed with patches of bare or leathery skin or with patchy coats during other times of year could be experiencing disease or various forms of skin irritation.
Skin mites and other parasites can irritate a deer’s skin and in severe instances a deer may pull or rub out clumps of its own hair in an attempt to remove the mites.
Although less common, it is also possible for deer to contract mange. The public is encouraged to report incidents of deer with severe hair loss, preferably including a photograph of the animal to the New York State Department of Environmental Conservation.
Photo of deer shedding winter coat courtesy DEC.
