Wednesday, December 21, 2011

Winter Wanderers

Winter often brings rare avian vagrants to the Middle Atlantic states and the last couple of weeks have been especially kind to those of us who enjoy seeing these feathered vagabonds. Recently three unusual species have turned up in central Pennsylvania, two of them in the same location, Blue Marsh State Park near Reading, PA.

The first rarity was a female Rufous hummingbird, a western species. Rufous hummingbirds have made appearances at a half dozen spots around the state recently, one of which was close to my home in York County.

Rufous Hummingbird (female)
Hummingbirds are the smallest bird in the world and are found only in the western hemisphere and mostly in South America. They're the only avian species capable of backward flight (they can also fly sideways). Their wings beat so fast (70 times a second in normal flight, 200 times a second in a power dive) that they're only a blur to the eye, and they're so tiny they must consume up to 8 times their bodyweight in food in a day to stay alive. Go here for more fascinating facts about these birds.

The other two wanderers to make their way to Pennsylvania were both gulls. One is the Glaucous gull which is completely white. Most gulls show some black or gray, but the Glaucous, a species which breeds in the arctic, has only a black spot on the tip of its beak.

Glaucous Gull
The third visitor was another western species called a Franklin's gull. The Franklin's adult looks superficially like the Laughing gull common to the east coast of North America, but it's smaller and differs in a few details. The bird seen at Blue Marsh was a juvenile in winter plumage.

Franklin's Gull
All this and winter's just getting started.