Cliff Swallow, Petrochelidon pyrrhonota

Cliff Swallow
The buff rump patch of the adult Cliff Swallow is the familiar field mark that makes it easy
to identify the species in flight. For the photo above, I carefully planned to capture the exact
moment when the bird's wingtip touched the water. (Or maybe not.)

Cliff Swallow
An adult Cliff Swallow, above; below, a juvenile, showing the edges of its yellow gape. 

Cliff Swallow

Cliff Swallow
A Cliff Swallow clinging to a rough surface, the posture in which they often
have to build their nests.

Cliff Swallow
Above, an adult Cliff Swallow gathering clay to build a nest; a nest under construction is shown below.

The nests can be fixed to cliffs, as the bird's common name suggests, but are often found on buildings. The most
famous example is at the Mission of San Juan Capistrano in Southern California, to which, in a tradition immortalized
in song, "the swallows come back" every spring; their return is celebrated on March 19, St. Joseph's Day. Cliff
Swallows nest every spring in my area at both Palo Alto Baylands and Shoreline Park in Mountain View, as well
as on the Stanford campus.

Cliff Swallow
Above, an adult Cliff Swallow building a nest. Below, other nests; more often than not, a crevice with a floor like the nest site above is not available, and the nests are built to hang from the junction of a vertical and overhead horizontal surfaces.

Cliff Swallow
Above, a nestling begging for food from the portal of its
mud nest; below, an adult feeding a nestling.

Cliff Swallows

Cliff Swallow
This rare albino Cliff Swallow was flocking with normally plumaged birds of the species in Sierra Valley, far
eastern California. The picture was used as an illustration in an article in Birding magazine on forms of pigment
deficiency in bird feathers.