If you spent your summers on the wind-swept plains of the Arctic, where would you spend your winters? How about the Kenai Peninsula? Well, surprisingly, that's where one juvenile snowy owl landed last November.
The "snowy" was found along the bluffs north of Kenai by a good samaritan who noticed it wasn't able to fly. After being examined by a local veterinarian for injuries and given a clean bill of health, the owl is now fattening up on voles, lemmings and other small mammals as it recuperates from its travels.
Two other snowy owls made an appearance in Sitka in November, giving local birders an opportunity to observe one of the most striking and distinctive of the world's 146 species of owls.
So why are these large, mostly white owls showing up in areas outside their usual winter range? Like most other arctic-breeding raptors, the movements of this species are sporadic in nature, rather than consisting of regular migration routes. Some biologists believe the availability of their main food source (primarily lemmings and voles) dictates where they decide to winter. Other owl researchers believe that their wintering grounds are influenced by a combination of large scale weather events in addition to the variable abundance of their prey.
Snowy owls are a common sight in northern Alaska above the Arctic Circle, but are rare visitors to Southcentral Alaska. They breed in the summer along the north slope of Alaska, the arctic tundra of Canada, and along the northern coast of the continent from the Yukon to Labrador.
Some snowy owls remain over the winter in the areas where they nest. Others migrate to more southern latitudes, wintering on the prairies of western Canada, southern Ontario and Quebec, the northern United States and, sporadically, as far south as central California and the Gulf states from Texas to Florida. It is mostly first-year birds that visit these less frequented areas, with relatively few adult owls appearing. On average, immature males winter farthest south, adult females farthest north, with adult males and immature females in between.
The heaviest of North American owls, the snowy owl stands almost 2 feet tall. The female is larger and heavier than the male and can be slightly darker in color, which may be almost pure white. The ear-like feather tufts characteristic of many species of owls are greatly reduced in snowy owls and are rarely visible, giving the head a typically rounded outline. This is one of only a few species of owls that is active during the day.
Years ago when I just graduated from college and worked one summer for the Arctic National Wildlife Refuge on the arctic coastal plain, I was fortunate to see snowy owls nesting on their breeding grounds.
The nest was just a shallow depression scraped in the ground by the female. Most nests were located up on a knoll or tussock on the tundra, which provided the incubating females with a commanding view of the surrounding terrain.
The breeding success of snowy owls is very dependent on the lemming population in regions where owls depend on this small chunky mammal for food. When lemmings are abundant, the owls respond by laying as many as 11 or 12 eggs. When lemmings are less numerous, clutch size is reduced to 4 to 6 eggs. Snowy owls may not nest at all for a year or two if the lemming population crashes, or they may move 30 to 60 miles and breed in another area where lemmings are more numerous.
Snowy owls seem to be well adapted to cope with changes to their environment and their food supply. While food shortages may be a danger, their mobility permits them to move to areas where food supplies are sufficient. Some immature, inexperienced birds that wander beyond their normal winter range (such as our recent visitor) may suffer from starvation. However, human activities probably still pose the greatest danger to owls that winter in settled areas.
Elizabeth Jozwiak is a wildlife biologist at the Kenai National Wildlife Refuge. She studies a variety of species but enjoys every opportunity to work with owls.
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