Cliff Swallow

Cliff Swallow, Malheur NWR, Oregon on 29 May 2010 by Greg Gillson.

 

Cliff Swallows are rather common throughout the Pacific Northwest, especially near water east of the Cascades. In agreement with their name they do nest in colonies on cliffs, bridges, highway overpasses, under the eaves of barns, and in smaller numbers on porches and out buildings, especially in rural settings. They are not usually found in forest habitats or urban areas.

They need water nearby, as they build their nests of mud. Those nests are gourd-shaped structures--a mud ball usually with a protruding side entrance. The bird in the photo above is collecting one bill-full of mud at a time to build its nest on a cliff near the Buena Vista Station at Malheur National Wildlife Refuge in SE Oregon.

Field marks for this swallow include the compact shape with short square tail, creamy-tan rump, dark rusty throat, and pale forehead. It is the only swallow in the Pacific NW with a buffy rump. The call is rather grating.

As with all swallows, they primarily feed on insects on the wing. They often feed over water. Their bills are short, but very wide.

Cliff Swallows winter in South America. They first arrive in the Pacific Northwest by the first of April. Fall migratory flocks form in July and most birds are gone by the end of September, though some stragglers may remain, rarely to November.

Nature Journal: Sunbathing Cliff Swallows

Cliff Swallows sunbathing on a roof, Jackson Bottom Wetlands Preserve, Hillsboro, Oregon on 7 July 2010 by Greg Gillson.

 

We had a rather cool and wet spring. Thus, when it finally warmed up just after Independence Day [Editor's note to visitors: it always rains on all holidays in western Oregon.], I went out on the trails at Jackson Bottom one hot morning and found these Cliff Swallows sprawled out and panting on the roof of this wildlife viewing stand.

Why?

I got out my trusty reference guide, The Audubon Encyclopedia of North American Birds (1980) by John Terres.

It turns out all sorts of birds sunbathe, fluffing up their feathers and panting. Some take it to the extreme by flopping their wings forward wildly, gasping for air, while lying prostrate.

That seemed to be the case for the birds observed here, many of which were in a dusky juvenal plumage.

Why do they do it?

Terres' sources indicate that sunbathing benefits birds in several possible ways. Heat is absorbed (they were just cold and wanted to warm up); Vitamin D is produced; skin and feather parasites may move off the back and to a place where the birds can remove them. Some birds apparently sunbathe during the time of molt--perhaps it stops the skin from itching?