Cliff Swallows Petrochelidon pyrrhonota are one of our last swallows to return from their wintering grounds, but once they arrive they get busy in a hurry, building their mud nests in dry covered areas, historically under rock overhanging places on cliffs, but now often under man-made structeures. Bridges, culverts, highway overpasses all work well as long as there is a good supply of mud nearby to build the nests.
Yesterday I took a walk at the Nisqually National Wildlife Refuge near Olympia, Washington, and in the covered viewing areas on the boardwalk the Cliff Swallows were busy.
Look how much mud they can fit into their huge mouths, which most of the time work as efficient means to capture small flying inects by swooping through the air with the mouth wide open to catch bugs. Also note the tan colored upper tail feathers, a good identification field mark for these swallows in flight.
Here is an example of the nests they are building.
Cliff swallows breed throughout much of Alaska, southern Canada and the United States, migrate south to winter in a large part of South America.
I suspect that their arrival later than most of the cavity nesting swallows is a safe strategy for them, because competition for nest sites may be lower, and insect populations are more safely predictable a bit later in spring.
Thanks for reading. Good birding.