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Sitka Black-tailed Deer

Many people in Alaska are thrilled each year at a fleeting glimpse of a deer bounding across a highway or standing motionless in a woodland clearing. Sitka black-tailed deer occur naturally on southeastern Alaska islands and in a narrow strip along the mainland.  Sitka deer were transplanted to several rain forest areas along the Gulf of Alaska between 1917 and 1934.  There they have established populations around Yakutat, Prince William Sound, and Afognak and Kodiak Islands.  They are not expected to spread any farther than that due to topographic and climatic barriers.

The Sitka black-tail is different than other deer as it has a vertical pattern of seasonal migration.  In the spring, when the snows begin to melt in high mountains and ridges, the herds begin to move upward.  The bucks and yearlings usually climb to over 2500 feet, where they stay until the heavy snows of another winter begin to fall.  Does and their fawns, born in May, usually stay farther down on the mountains where the trees give more protection from predators. When snowfall continues and food becomes scarce, deer move lower in elevation into forests with large trees and an abundance of understory plants.  Tall trees, with massive limbs and well-developed crowns, can effectively catch the snow in the branches.  Studies show that snow depths in such forests are often only 60% as high as nearby unforested areas.  If snow persists, deer will move to lower elevation forests with southern exposure or near saltwater where less snow accumulates. 

During the winter, deer prefer small succulent evergreen plants called forbs.  Preferred forbs are relatively high in protein and nutritional value, and include plants with such unusual names as bunchberry, 5-leaf bramble, and golden thread.  If snowfall continues, forbs will be buried under the snow.  Deer will then begin feeding on woody shrubs, such as blueberry, lichens, and even seaweed and kelp.  This diet is less nutritious and deer will begin to utilize their fat reserves.  During periods of prolonged deep snow, deer may die of starvation. Deer are herbivores or plant eaters and their usual diet may consist of grasses, skunk cabbage, forbs, and bushes such as their preferred huckleberry.  Other plants may also be eaten.  Sitka deer are ruminants, or cud-chewing.  They have a four-compartment stomach, regurgitate or bring up their food, and chew the food again as cud. 

An interesting characteristic of the Sitka black-tailed deer is that they are colorblind.  They do not appear to see an object that does not move or, if they do, they are not concerned about it.  However, the slightest movement causes the deer to focus its eyes upon the object that has moved.  The deer will then freeze and intently study whatever has attracted its attention.  Even the blinking of an eyelid can be enough to send an alerted deer running for safety. So, when you are out in the forest, be sure to watch for these beautiful animals, but remember they can see every move you make. 

For more information about deer, view the Alaska Department of Fish and Game Wildlife Notebook Series.