Cliff Swallow

Petrochelidon pyrrhonota

Introduction

The Cliff Swallow is a widespread and social aerial insectivore. It breeds from Alaska across Canada to the Maritimes, the US, except the southern Atlantic and Gulf states, to southern Mexico. A Neotropical migrant, this bird spends its winters in South America.

Identification

Adult Male (spring/summer)

Bright buff-white forehead, metallic dark blue cap, brick-red face and upper throat. Lower throat blue-black. Pale gray nape extends around to breast. Breast buffy gray, belly white, undertail coverts white with buffy flecks. Back metallic dark blue with buff lines, rump pumpkin orange. Tail blackish blue. Eyes, beak and feet are black.

Adult Female (spring/summer)

Sexes are similar.

Juvenile

Generally similar to adult much duller overall.

General Information

General:

Compact, with broad based wings and medium length squaretail. Length: 13cm. Wing: 28-30cm. Weight: 19-34grams.

Behaviour:

The Cliff Swallow can see seen foraging on the wing for small flying insects, like mosquitoes, often over open fields or small bodies of waters, around bridges and overpasses, grasslands and urban waterways. When in feeding flocks with other species of swallows, they often stay higher in the air. 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. Very colonial, they preen, feed, drink and bathe in groups and stick together in large flocks during migration.

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 ‘crèches’. 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 possible they also identify them visually as well. Nest is gourd shaped made of mud placed on cliff sides, caves, eaves, bridges, etc. Clutch is 1-6 white, creamy or pinkish with brown speckles.

Similar species:

Barn Swallow.

Conservation Status:

Listed as Least Concern and recent trends show that populations are stable.

Maps & Statistics

Capture Rates

Cliff swallows are infrequent visitors to the old fields of Colony Farm where we band and captures are sporadic with a few individuals in most years.

Ageing and Sexing (Band Size: 1)

Molt Summary:

PF: HY/SY complete, PB: AHY/ASY complete. Molt occurs primarily on the winter grounds.

Juvenile

June - December

Juveniles like this HY in July show brownish and less well defined forehead patches than adults and mottled, brownish washed cheeks, throats and backs. Juvenal flight feathers are fresh with no wear.

Separating juveniles from adults is easy as this photo of side by side adult (AHY) left and juvenile (HY) right illustrates.

AHY/ASY

March - February

Having complete preformative and adult prebasic molts makes ageing adult birds impossible and sexing is also difficult given very little difference in biometric measurements such as wing chord and that males can also develop partial brood patches.

The two photos below are of adult (AHY) birds in summer (July and August) showing buffy and well defined forehead patches and chestnut throats and cheeks.

Adult (AHY/ASY) flight feathers (primaries, secondaries and rectrices) are relatively abraded and worn in summer compared to juveniles which show fresh flight feathers with little or no wear.