Alberta is home to a variety of swallow species that migrate to the province each spring to breed during the summer months. Swallows are small, agile songbirds with pointed wings, tiny bills, and small feet. They are found across North America and are known for their graceful flight and aerial acrobatics as they hunt flying insects on the wing. Alberta’s swallows belong to the family Hirundinidae, which includes familiar species like barn swallows, tree swallows, and cliff swallows.
Barn Swallow
The barn swallow is one of the most widespread and recognizable swallow species in Alberta. These birds have steely blue upperparts, a cinnamon-colored forehead and throat, a pale underside, and a deeply forked tail. Barn swallows are found throughout Alberta in summer, often nesting inside barns and under bridges where they build mud nests to lay their eggs. They are aerial insectivores that feed primarily on flies, catching them mid-flight with incredible precision. Barn swallows migrate south to Central and South America for the winter.
Identifying Features
- Blue back and wings
- Pale underside
- Rusty red forehead and throat
- Long, deeply forked tail
Range in Alberta
Found across the province in summer. Widespread and numerous. Absent in winter.
Habitat
Open areas near structures for nesting, including barns, stables, sheds, bridges, and culverts. Often found near water hunting for insects.
Diet
Feeds exclusively on flying insects like flies, mosquitoes, moths, and beetles.
Nesting
Builds nests of mud pellets lined with grasses and feathers attached to vertical surfaces on buildings, cliffs, or other structures. Nest is an open cup shape. Lays 3-7 eggs that incubate for 14-16 days.
Tree Swallow
Tree swallows are small, iridescent blue-green birds that breed in summer wetlands and woodlands throughout Alberta. Unlike other swallows, tree swallows nest in tree cavities rather than constructing exposed mud nests. They compete aggressively for nest sites. Tree swallows form large flocks during migration and on their wintering grounds in the southern U.S. and Mexico.
Identifying Features
- Glossy blue-green upperparts
- White underside
- Smaller and more compact than other swallows
Range in Alberta
Found across much of the northern two-thirds of the province in summer, absent from the extreme southeast. Winters along the U.S. Gulf Coast and farther south.
Habitat
Open wetlands, lakes, rivers, and woodland clearings. Requires tree cavities near water for nesting.
Diet
Feeds on insects like flies, beetles, moths, butterflies, and dragonflies.
Nesting
Nests in abandoned woodpecker cavities or nest boxes. Lays 5-7 white eggs that incubate for 13-16 days.
Violet-green Swallow
The violet-green swallow is a large, handsome swallow with white underparts and brilliant iridescent green and violet-blue upperparts. In Alberta, it is primarily restricted to nesting in the Rocky Mountains and foothills west of Calgary. Violet-green swallows forage widely over open habitats at high elevations for flying insects. They migrate to western Mexico for the winter.
Identifying Features
- Deep violet-blue back and wings
- White underside
- White patches on either side of rump
Range in Alberta
Summer resident in the west and southwest, mainly in the foothills and mountains. Rare in central and northern Alberta. Winters in western Mexico.
Habitat
Open mountain meadows, foothills, lakes, rivers, burns, and clearings in coniferous forest.
Diet
Feeds aerially on flies, bees, wasps, winged ants, and other flying insects.
Nesting
Nests in old woodpecker cavities in dead snags or aspen trees. Lays 4-5 white eggs that incubate for 15 days.
Northern Rough-winged Swallow
The northern rough-winged swallow is a drab, brownish swallow with a pale throat and subtle plumage. It is a common breeding species across much of Alberta, usually found along rivers, creeks, wetlands, and other bodies of water where it nests. Northern rough-winged swallows catch insects in flight over waterways and fields.
Identifying Features
- Plain brown upperparts
- Pale throat
- Faint brown breast band
- Short, squared tail
Range in Alberta
Common summer resident across most of Alberta. Winters from the southern U.S. through Middle America to Panama.
Habitat
Lakes, ponds, rivers, wetlands, and open fields. Requires vertical surfaces on bridges, cliffs, or buildings for nesting.
Diet
Eats flying insects including flies, mayflies, winged ants, bees, wasps, and beetles.
Nesting
Builds nest in cavities, crevices, and tunnels, often on bridges and culverts. Lays 4-6 white eggs that incubate for 13-15 days.
Bank Swallow
The bank swallow is a small brown and white swallow with a distinctive brown breast band. As its name implies, bank swallows nest in colonies excavated in vertical banks and bluffs along rivers and shorelines where the ground is bare of vegetation. They breed across much of Alberta near suitable nesting sites. Bank swallows migrate in large flocks to winter in South America.
Identifying Features
- Brown back with white underside
- Distinct brown breast band
- Small body and rounded wings
Range in Alberta
Summer breeding resident across much of the province except for the extreme north. Winters in South America.
Habitat
Riverbanks, lakeshores, roadcuts, and cliffs with vertical banks of dirt or sand for nesting colonies.
Diet
Eats flies, moths, beetles, flying ants, winged termites, and other insects captured in flight.
Nesting
Digs breeding tunnels into nearly vertical banks and bluffs with many pairs nesting together in a colony. Lays 4-5 white eggs.
Cliff Swallow
The cliff swallow is a compact, stocky swallow with a square tail, pale rump, and dark throat. As their name suggests, cliff swallows build flask-shaped mud nests under cliff overhangs, on buildings, and under bridges across Alberta. They form dense colonies during breeding season and migrate in enormous flocks. Cliff swallows winter in southern South America.
Identifying Features
- Pale orange rump
- Dark blue-black throat patch
- Compact body and rounded wings
Range in Alberta
Found throughout Alberta in summer though less common in the far north. Widespread and numerous. Winters in southern South America.
Habitat
Open and semi-open areas near nesting structures including cliffs, rock outcrops, buildings, and bridges.
Diet
Eats insects like flies, bees, wasps, and flying ants caught in flight.
Nesting
Builds gourd or flask-shaped mud nests on cliffs and structures in dense colonies. Lays 3-6 white eggs.
Migration
All swallow species that breed in Alberta are migratory, traveling astonishing distances to overwinter in the tropics. Migration allows them to take advantage of abundant summer food resources to raise young, then escape harsh northern winters for warmer southern climates.
Most swallows migrate at night and travel in large mixed-species flocks that can number in the millions. They navigate using a variety of cues including the earth’s magnetic field, the stars, and visual landmarks. Many swallows return to the exact same nesting sites each spring, exhibiting incredible homing precision across thousands of miles.
Spring Migration
Most swallows arrive back in Alberta in May to re-establish breeding territories and build nests. Tree swallows are often the first to return, followed by cliff and barn swallows. Migration proceeds northward with the most northerly breeding populations arriving latest.
Fall Migration
Swallows form large premigratory roosts in late summer before heading south, sometimes with hundreds of thousands of birds. Most leave Alberta in late August and September. Juveniles migrate earlier, followed by adult females and then males. Migration is completed by late October.
Status and Threats
Swallow populations face a variety of threats on their breeding grounds, migratory routes, and wintering areas. Habitat loss, climate change, pesticides, collisions, and competition all take a toll. Several species including bank swallow and barn swallow have declined significantly in parts of their range.
However, many swallow species remain numerous and widespread in Alberta thanks to abundant nesting habitat in rural settings. Providing nest boxes, reducing pesticide use, and protecting wetlands and other breeding sites can aid swallow conservation.
Species Status in Alberta
Species | Status |
---|---|
Barn Swallow | Declined but still common and widespread |
Tree Swallow | Abundant and increasing in Alberta |
Violet-green Swallow | Uncommon and local in western Alberta |
Northern Rough-winged Swallow | Common summer resident province-wide |
Bank Swallow | Declining modestly but still common |
Cliff Swallow | Abundant summer resident throughout Alberta |
Conclusions
Alberta provides important summer breeding habitat for six species of swallows that migrate to the province each spring and nest here before returning south each fall. The barn swallow, tree swallow, violet-green swallow, northern rough-winged swallow, bank swallow, and cliff swallow can all be found across various parts of the province during summer.
These aerial insectivores are graceful, agile fliers that perform remarkable migrations and exhibit interesting nesting behaviors. Providing habitat protection and reducing threats during both the breeding season and migration are important for the conservation of Alberta’s swallow populations.