Barn Swallow

About

The Barn Swallow (Hirundo rustica) is the most widespread species of swallow in the world. It is a distinctive passerine bird known for its deeply forked tail, iridescent blue upperparts, and rufous underparts. Highly aerial, it is a skilled insectivore, often seen gracefully hawking insects in open country, particularly near water and human habitation. It is a long-distance migrant, breeding across the Northern Hemisphere and wintering in the Southern Hemisphere.

Size & lifespan

Length

17-19 cm (including outer tail streamers of up to 7 cm)

Wingspan

32-34.5 cm

Weight

16-22 g

Lifespan

Typically 2-4 years in the wild, with records up to 11 years

Diet

Insectivore, primarily aerial insects

Physical characteristics

Plumage

Adults have iridescent steel-blue upperparts, a rufous (chestnut) forehead and throat, separated from the creamy-white to buff underparts by a broad, dark blue breast band. The tail is deeply forked with long outer streamers, and white spots are visible on the inner webs of the tail feathers when spread.

Beak shape

Small, flattened, and triangular, adapted for catching insects in flight; black in color.

Eye color

Dark brown.

Leg color

Short, blackish legs and feet, adapted for perching rather than walking.

Distinguishing features

Deeply forked tail with long streamers (especially in males), iridescent blue back, rufous face/throat, and dark breast band. White spots on the tail are a key field mark.

Juvenile appearance

Juveniles are duller than adults, with browner upperparts, paler and less rufous underparts, and a shorter, less deeply forked tail with shorter streamers. The breast band is often less distinct.

Seasonal changes

Plumage remains largely consistent throughout the year, though wear can make colors appear duller towards the end of the breeding season or migration. No distinct non-breeding plumage.

Sexual dimorphism

Males typically have longer, more prominent outer tail streamers than females, and often a slightly darker, more intense rufous on the throat and forehead. Females may have duller plumage and shorter streamers.

How to identify

1. 1

   Tail Shape

   Look for the deeply forked tail with long, slender outer streamers, especially prominent in males. White spots on the inner webs of the tail feathers are visible when spread.

2. 2

   Plumage Coloration

   Note the iridescent steel-blue upperparts, contrasting with the rufous (chestnut) forehead and throat. A dark blue breast band separates the rufous throat from the creamy-white underparts.

3. 3

   Flight Pattern

   Observe its characteristic agile, acrobatic flight, often low over open fields or water, with frequent glides and sharp turns as it hunts insects.

4. 4

   Habitat

   Barn Swallows are almost always found in open country, often near water and human structures like barns, sheds, or bridges, which they use for nesting.

5. 5

   Vocalization

   Listen for its cheerful, warbling, twittering song, often ending with a distinctive 'squeaky gate' sound.

Habitat & range

Biomes

Temperate grasslands, agricultural areas, open woodlands, savannas, and human-modified landscapes.

Geographic range

Breeds across most of the Northern Hemisphere, including North America, Europe, Asia, and parts of North Africa. Winters in the Southern Hemisphere, including South America, sub-Saharan Africa, and parts of southern Asia and northern Australia.

Elevation range

From sea level up to approximately 3,000 meters, though typically found at lower elevations.

Preferred environments

Open country with access to water, often near human structures like barns, bridges, and houses for nesting. Requires open air space for foraging and mud for nest building.

Behavior

Activity time

Diurnal.

Feeding habits

Exclusively insectivorous, catching insects (flies, beetles, moths, aphids, grasshoppers) in continuous, agile flight. They often forage low over fields, water, or pastures, especially in warm weather. They drink by skimming low over water surfaces.

Social behavior

Highly social, especially during migration and in wintering grounds, forming large communal roosts. During breeding, they are colonial, nesting in loose groups, but defend their immediate nest site. They often forage in mixed-species flocks with other swallows and swifts.

Flight pattern

Graceful, agile, and highly acrobatic flight, characterized by rapid wing beats interspersed with glides. They are masters of aerial pursuit, making sharp turns and dives.

Migration pattern

Long-distance migratory. Northern Hemisphere breeders migrate south for the winter, crossing vast distances, often thousands of kilometers. Migration occurs in large flocks, typically during the day.

Territoriality

Males defend a small territory around the nest site during the breeding season, primarily against other males. They are less territorial on wintering grounds.

Breeding & reproduction

Breeding season

Varies geographically, typically April to August in the Northern Hemisphere.

Nesting habits

Nests are cup-shaped, made of mud pellets mixed with grass and lined with feathers. They are typically built on vertical surfaces under eaves, inside barns, sheds, bridges, or culverts. Both sexes participate in nest building.

Clutch size

Typically 2-3 clutches per season in warmer regions, 1-2 in cooler regions.

Egg description

3-7 (usually 4-5) white, glossy eggs, speckled with reddish-brown or purplish-grey spots, particularly at the larger end. Dimensions average 20 x 14 mm.

Incubation period

13-17 days, primarily by the female.

Fledging period

18-23 days after hatching. Young are fed by both parents.

Parental care

Both parents feed and care for the young. After fledging, juveniles remain dependent on parents for several days to weeks, often returning to the nest to roost.

Where to find

Field tips

1. Look up!. Barn Swallows spend most of their active time in the air. Scan the skies, especially over open areas.
2. Visit farms or rural areas. Their strong association with human structures makes farms, stables, and rural outbuildings prime locations.
3. Observe near water. They frequently skim over water to drink and catch emerging insects. Look for them at dawn and dusk.
4. Listen for their song. Their distinctive warbling song can often alert you to their presence, even before you see them.
5. Watch for mud nests. During breeding season, look for their characteristic mud cup nests attached to vertical surfaces under eaves or inside structures.

Similar species

Quick facts

Global Distribution:

Most widespread swallow species globally

Diet:

Strictly insectivorous, catching prey in flight

Nesting Material:

Mud pellets and grass, lined with feathers

Migration Distance:

Can travel thousands of kilometers between breeding and wintering grounds

Tail Streamers:

Longer in males, used in sexual selection

Fun facts

• Barn Swallows are considered a symbol of spring and good luck in many cultures due to their return from migration.
• Male Barn Swallows with longer tail streamers are generally preferred by females, indicating better health and genetic quality.
• They are incredibly agile flyers, capable of catching insects at high speeds and performing complex aerial maneuvers.
• Barn Swallows often reuse their mud nests from previous years, sometimes repairing and adding to them.
• They drink water by flying low over the surface and scooping it up with their open mouths.

Scientific classification

Kingdom

Animalia

Phylum

Chordata

Class

Aves

Order

Passeriformes

Family

Hirundinidae

Genus

Hirundo

Species

Hirundo rustica

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