If I glimpse a bird fly by that is a little more than 5 inches long, with a square tail, pale rump and white forehead, there’s a good chance it’s a Cliff Swallow.
Cliff Swallow wings are blue-gray, as are their crowns. The cheeks are rusty brown; their throats are dark.
These are the famous swallows of San Juan Capistrano whose return has been recorded around March 19 since 1775. They winter in Paraguay, Brazil, and Argentina. Cliff swallows eat insects, catching them in in mid-flight with beaks that are surrounded by tiny bristles that help trap the bugs.
It’s been suggested they could be renamed Bridge Swallows because so many nest on highway bridges.
Historically, these colonial nesters chose cliffs and bluffs to build their gourd-shaped nests. Each nest is built by a pair and it has a small opening at the bottom. They “mason” their home with bead-like bricks of mud carried to the nesting site in their beaks. Some 4-5 eggs are incubated for only about two weeks.
Interestingly, Cliff Swallows are parasitic nesters in their own colonies. Females have been known to carry an egg in their beaks to an empty nearby nest. When the neighbors return, they seem to accept them and raise the chicks as their own.