Monday, June 20, 2011

Pacific NW specialty... Varied Thrush

Varied ThrushVaried Thrush, Beaverton, Oregon, 27 March 2011 by Greg Gillson.


Visiting birders to the Pacific Northwest often have Varied Thrush on their "target list" of bird species to see. Fortunately, this species is not rare, and are not difficult to find, if one knows where to look.

When I think of Varied Thrush habitat, my search image is of damp, dark, moss-covered Sitka spruce forests on steep, foggy hillsides overlooking the ocean in the Pacific Northwest. I know! My search image is something like this photo I took at Cape Perpetua on the central Oregon coast way back in August 2003:

Likewise, Varied Thrushes find their home in similar dense, damp high-elevation old-growth forests in mountains from Alaska to extreme NW California. Periodically, in winter, vagrant birds will be found far to the south, and even to the East Coast.

In winter, birds from the north or higher elevations move into the lowlands west of the Cascades. A winter snow storm will bring these birds out of cover and into backyard feeders and landscaping, where they favor fallen apples. As soon as the snow melts they disappear back into the dense brush. The bird photographed above spent the winter in my backyard in Beaverton, Oregon. But it never ventured out far from cover.

These birds eat berries, seeds, acorns, insects, and invertebrates that they forage from on or near the ground.

Their eerie songs are single hummed whistled notes, each given with a pause of about 3 seconds between them. Each note is a different pitch, first higher, then lower, but each far apart from each other. For instance, if they give a note in the middle of their frequency range, the next will be at the extreme end. This is very typical of thrush songs, even though this song is nothing like the flutelike, ethereal and very complex songs of that master singer, the Hermit Thrush.

Varied Thrushes appear similar to American Robins, also a thrush. They differ in the orange eyestripe and orange patterning in the wings, and black necklace across the chest. Males, such as the one in the photo, are darker gray-black above and deeper orange below than females.