Weekly Bird Report
5:07 pm
Wed December 18, 2013

Unprecedented Incursion of Snowy Owls across the Cape and Islands

Snowy Owls are an irruptive species. Rarely, an invasion or irruption will occur and several or more may arrive as they move south in search of food. The entire northeast is currently involved in “the mother of all irruptions” as an unprecedented incursion of these powerful and awe-inspiring owls is happening as you hear this. The species has been reported from beaches all over the Cape and Islands and it seems no beach or headland in the region has not had owls reported this past week. This “irruption” is already of historic proportions.

In Atlantic Canada, expert birder and researcher Bruce Mactavish reports an astounding 304 individual Snowy Owls on a couple of peninsulas of land in southeast Newfoundland this past week. This staggering number of Snowy Owls is unheard of. This irruption is breaking all records. The Cape and Islands are loaded and despite rather nasty weather this past weekend, the Outer Cape CBC recorded 13 Snowy Owls - which was almost double the previous high in this count's long history. Meanwhile, the Newport, R.I./Westport, MA CBC recorded 12 Snowy Owls, the highest total ever recorded in the 65 years that this count has been conducted. Two CBC’s, 2 new record totals. This is the winter of the Snowy Owl!

There is not a person alive who will fail to be impressed at the sight of a Snowy Owl. They are large birds that live virtually all of their lives on the treeless Arctic tundra. Unlike most other owls, Snowys must be able to live and hunt by daylight, as in the summer months it is constant daylight 24/7 where they nest, “in the land of the midnight sun.” This species is circumpolar in its distribution. This means that it is found right across the top of the planet, as harsh an environment as anywhere on earth.

The most favored locale for the entire region, indeed for the entire United States, is at Logan International Airport in Boston. The runways and surrounding marshes are always popular with snowy owls and especially in big flight years. Its wide-open spaces and windswept runways undoubtedly recall their tundra breeding areas. Most importantly, there are abundant food resources available to the owls in the form of rats, mice and a wide selection of waterfowl.

While most owls are superbly adapted nocturnal predators, heavily modified, like some sort of eavesdropping, slow-flying, stealth aircraft that locate and ambush unknowing prey, Snowy Owls use a different strategy. These birds are strong-flying diurnal (in other words: daytime) predators. Their prey often sees them coming. Deceivingly fast, they are able to capture many kinds of birds, on the wing in direct flight. They are a magical, mythical bird that are greatly enhancing this holiday season.

Young Snowy Owls have lots of black and mottling in their plumage. The owls get whiter as they get older, with each successive molt. Their primary food is small rodents and the meadow voles on Cape and Island beaches, as well as Norway rats, which will keep the owls fat and sassy while they are visiting. This past weekend Snowy Owl prey seen being eaten included several sea ducks, a Horned Grebe and an Eastern Cottontail on Nantucket.

Get out to a beach near you and take a good look at any white lumps in the grass, on a jetty, or on the beach. It might be a lot more than it appears!