The cliff swallow is a 5-inch long bird with a very short bill. Both sexes are similar in their varied coloration, with brown wings, a distinct white or tan forehead, black to blueish crown, gray nape, dark red throat, rusty breast and rump patch, and a white belly. They enjoy a widespread breeding range throughout the Midwest and western United States, Canada, and Alaska. These swallows are a long-distance migrants, wintering in southern South America. This is the famous swallow of San Juan Capistrano, California, returning there to breed every year in February and March. They are quite gregarious and migrate in flocks in addition to their dense nesting aggregations, which may contain as many as 2,000 birds.
Cliff swallows feed on the wing, catching insects in flight high over terrain or while skimming low over water. They take a large variety of flying insects as well as spiders, and sometimes eat berries. They are found in open country or forest clearings, just about anywhere where cliffs, bluffs, or structures, like barns or bridges are available for their nesting colonies. They nest near water bodies where the swallows find a ready supply of mud for the construction of their gourd-shaped mud nests. Nests used the previous year are often refurbished, permitting earlier broods and enhanced survival of offspring, as opposed to spending the time required to build a new nest from scratch. Late nesting often results in decreased survival of young. And the mud/clay nest material is similar to sod bricks used in historic rural house construction and is resilient and long lasting. The 3 to 6 eggs hatch after two weeks and both parents will bring food to the nestlings.
Though Cliff swallows are aggressive compared with the more reticent Barn swallows, they are nevertheless subject to nest predation by the even more assertive House sparrows, which will sometimes take over a Cliff swallow nest, destroying the eggs and remodeling the nest with their own style of grass and other vegetation that then precludes further use by the Cliff swallows.
The highly gregarious lifestyle confers advantages to birds in sharing knowledge of food and resource sites, such as good sources of mud for nest construction. They can also readily detect predators and swarm them or escape before being attacked. But close proximity to large numbers of other swallows also allows easy transmission of parasites and disease vectors. As such, Cliff swallows typically harbor large numbers of ticks, fleas, and other ectoparasites.
The Audubon Society predicts little change in the breeding range of Cliff swallows as global warming proceeds.
Photos taken by James Taulman at the Bosque Del Apache National Wildlife Refuge, using Nikon P900 camera.