Wednesday, January 9, 2013

Snowy Owls Return to Washington's Nisqually NWR

Snowy Owls have returned to Nisqually National Wildlife Refuge in NW Washington state for the second consecutive year, visible every day since six owls were spotted on the morning of November 13th. It is extremely unusual to see Snowy Owls for two consecutive years. They typically range this far south only once every five to ten years in an event called an irruption (the periodic movement of numbers of birds into unusual ranges for a season). Last winter's irruptive event was one of the most pronounced on record, with owls seen as far south as Texas; one even made it, for the first time ever, to Hawaii.

Nobody is completely certain about the factors that influence an irruption, but it is almost certainly linked, at least in part, to fluctuations in the lemming population. A single Snowy Owl eats 3 to 5 lemmings per day, a total of up to 1,600 per year, so the movements of Snowy owls naturally depend on this food source. But for irruptive movements to occur on a continent wide basis, other factors, such as weather, may also be influential, though a clear relationship has never been determined.

These owls typically breed only at the far northern fringe of the continent, truly in the Arctic. Because of their icy home territory they are distinctively bright white (younger birds have black barring which diminish as they age). They are also the heaviest of all North American Owls. During winter months, they range across Canada and into New England, New York and the Northern Plains, but for those of us in the Pacific Northwest seeing a Snowy Owl is a rare treat. At the Refuge these owls are typically seen in the new restoration area and beyond, in the tidal flats where there are few trees. They may remain resting on the ground for hours at a time, regarding the world with sleepy yellow eyes, comfortable with exposure perhaps because they are so accustomed to the treeless habitat of the tundra.

Snowy Owls have also been sighted at other locations throughout Washington, but as of the time of printing, this year's event has not yet been classified an irruption. Nonetheless, the owls should be visible throughout Northwestern Washington through February. The owls at Nisqually are typically far out on the tidal plain near the mouth of the Nisqually River and are consequently difficult to see from visitor areas. For better views, head to Damon Point near Ocean Shores.