Rock Wren, Salpinctes obsoletus
Rock Wrens are drably-plumaged little birds, well-camouflaged against the gray-brown rocky hillsides in the American West that provide their usual habitat. But they are popular with birders -- relatively difficult to find and see, and characterized by delightful behavior. Pete Dunne in his "Field Guide Companion" describes them as "sassy" and "rock-frolicking", "nimble and hyperactive."
These birds typically forage and nest in the crevices between the loosely piled rocks that are found in their usual hillside habitat, shown in the second image down from the top. But the one pictured in the two pictures above and the three below somehow found itself in the flat farmland of the California Central Valley and apparently recognized in the exhaust pipe of my car something reminiscent of a hillside rock crevice.
The mating and nesting behavior of Rock Wrens has not been systematically studied much, but they appear to be monogamous and maintain their pair bonds throughout the year on their territories, above and below in October and September respectively. Their playful nature shows itself in chasing play even out of courtship season, as I was able to observe and photograph in the pair below.
