Description:

The Cliff Swallow is quite widespread, its range extending from southern Alaska, across Canada to the Maritimes, the continental US, to southern Mexico. A neotropical migrant, this bird spends its winters in South America. It falls in the order of Passeriformes, passerines or perching birds, and is a member of the Hirundinidae family, which include other swallows and martins.

Identification:

General: measuring 5.5 inches long and weighing in at around 21 grams, the Cliff Swallow is a small, stocky bird with pointed wings and a short, square tail.

Adult: has a dark grey-blue crown, back and wings, a dark tail, white belly with spotted undertail coverts, although some white streaking on the back is not uncommon. The auricular and throat are dark rufous, and the white forehead and buffy-coloured nape and rump are fairly distinctive. Both the adult male and female have identical plumage.

Juvenile: markings are quite variable in juvenile Cliff Swallows. Generally similar to the adult, but will have a brown crown and back, instead of dark blue; auriculars will be dark, but may have a pale throat.

Similar Species: The Barn Swallow has a deeply forked tail, a dark rump and forehead, and is rusty-coloured underneath. The Cave Swallow's forehead is a dark orange, with a pale throat and auriculars, but is local to the south of Texas and parts of Central America.

Behaviour: Aerial insectivores, these birds can see seen diving in the air after small flying insects, like mosquitoes, often over open fields or small bodies of water. One Cliff Swallow will often alert others with a call when a swarm of insects is found; by doing so, thus keeping better track of their food.

Habitat: Cliff Swallows prefer open areas, often near water, and avoid heavily forested, desert, or high mountainous environments. Originally nesting on cliffs as their name implies, they have adapted to living on human-made structures, and will often build nests under the eaves of houses and bridges.

Information:

Although they can nest alone, Cliff Swallows are one of the most colonial of passerines, and nest together in huge colonies, sometimes hundreds or thousands strong. They build a jug-shaped nest out of mud pellets, lined them with soft grass and feathers and often very close to one another. Birds in the same colony breed synchronously, and are known to steal nesting material from their neighbours. Cliff Swallows are brood parasites within their own colony as well; females will lay their own eggs in another nest, sometimes even carrying the egg in her bill to transport it.
The young in a colony gather together in large groups called 'creches'. When parents return from feeding, they can recognize their young primarily by voice; but because of the variability in head markings on juveniles, it is possibly they also identify them visually as well.

Conservation Status: (Least Concern)

Cliff Swallows currently hold a conservation status of Least Concern and and recent trends show that populations are stable. These birds have in fact adapted well to urbanization and the construction of concrete bridges and buildings have lead to an increase in suitable nesting habitat. There is some concern, however, about House Sparrows taking over Cliff Swallow nests, as they are the same sized bird.