Tag Archives: deer introduced to Kodiak Island

Sitka Black-Tailed Deer (Odocoileus hemionus sitkensis)


Twenty-five Sitka black-tailed deer were introduced to the north end of Kodiak Island in three transplants from 1924 to 1934, and another nine deer were introduced in 1934. The deer population has since spread to most areas of the Kodiak archipelago, and despite the limited gene pool from the original small herd, the population appears to be healthy. The size of the deer population fluctuates from year to year, depending on the harshness of the winter, but biologists estimate there are approximately 70,000 deer on the archipelago.

Sitka black-tailed deer are smaller, stockier, and have a shorter face than Columbia black-tails. An average adult doe weighs 80 lbs., while an average buck weighs 120 lbs. Much larger bucks weighing as much as 200 lbs. have been reported. The summer coat of a Sitka black-tail is light reddish brown, while the winter coloration is dark brownish gray. The antlers are fairly small compared to other species of deer and typically have three or four points on either side, including the eye guards. A very large buck might have five points on each side, including the eye guards.dsc_0043

During the summer, Sitka black-tailed deer feed on herbaceous vegetation and the leaves of shrubs. During the winter when there’s snow on the ground, their diet is restricted to woody browse, which is not an adequate diet to sustain the deer over a long period. During the spring on Kodiak, deer range from sea level to approximately 1500 ft., where they forage new plant growth as the snow line recedes. Deer continue to disperse into the higher altitudes as the snow melts, and they can be found anywhere from sea level to 3000 ft. in the summer. After the first frosts in mid to late September, the forage plants die, and the deer move out of the high elevations.

The breeding season, or rut, begins in mid-October and runs through November, and once again, the deer can be found from sea level to 1500 ft. Depending on snow accumulation, Sitka black-tails usually descend below 1000 ft. in the winter. During periods of heavy snow, many deer congregate on the beach or in heavily timbered areas at low elevations. Deer are good swimmers, and at any time of the year, Sitka black-tailed deer can be seen swimming across the long, narrow bays on Kodiak Island.

dsc_0030-2Does begin breeding when they are two and continue to produce fawns until they are ten to twelve years old. Does as old as fifteen normally don’t produce any offspring. Does between the ages of five and ten are in their prime and usually produce two fawns a year. Mating season on Kodiak occurs between mid-October and late November. The gestation period is six to seven months, so fawns are born from late May through June. Twins are the most common, although many young does only produce a single fawn, and triplets do sometimes occur.

Sitka black-tails have an average lifespan of ten years, and the mortality rate for fawns is between 45% and 70%. Severe winters are the number one threat deer face on Kodiak Island. During mild winters with moderate temperatures and little snow accumulation, the deer population increases, but a harsh winter can cause a dramatic population decrease. In contrast, limited, dispersed hunting pressure seems to have little effect on deer numbers in most areas.dsc_0023

Deer are often seen in the town of Kodiak, and in more remote areas of the island where they rarely see humans, it is not unusual to have a deer walk right up to you. Bears sometimes kill deer weakened by a harsh winter, but in the summer, you often see Kodiak bears and Sitka black-tailed deer standing within a few feet of each other on a stream bank. With so much other food readily available, bears do not seem interested in chasing and attacking deer, and the deer do not seem to consider the bears a threat. Nearly ninety years after Sitka black-tailed deer were first introduced to Kodiak Island the population has endured and appears to be healthy.