Refuge Notebook
Peninsula Clarion Article
Dated
12 January 2001
A snowy owl visits the Kenai Peninsula
by Elizabeth
Jozwiak
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 thats 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 wasnt 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 worlds 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 sporatic in nature,
rather than consisting of regular migration routes. Some biologists believe the
availability of their main food source (which is 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
and Southcoastal 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
one half meter tall. The female is larger and heavier than the male, and can be
slightly darker in color than the male, 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 which is active during the day.
Years
ago when I just graduated from college and worked one summer for the Arctic NWR
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 very abundant, the owls respond by laying as many as 11 or 12
eggs. When lemmings are less numerous, clutch size is reduced to 4-6 eggs. Snowy
owls may not nest at all for a year or two if the lemming population crashes,
or they may move 50 - 100 kilometers 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 but human activities probably
still pose the greatest danger to owls that winter in settled areas.
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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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