Bank Swallow

Riparia riparia

Introduction

Named after its most-often chosen breeding habitat (as riparia means ‘riverbank’ in Latin), the Bank Swallow is North America’s smallest swallow. The breeding range for this bird stretches over central North America, from Alaska to the Atlantic, but excludes the most southwestern coastline, and usually no further south than Texas and New Mexico. A neotropical migrant, the Bank Swallow spends the winter in all areas of South America. It is even widespread globally, with populations across Africa, Asia, and Europe (where it is called the Sand Martin). It is much more common in the interior of BC, but is a visitor here in the lower Fraser Valley. Keep an eye out for these birds during the fall migration season, as they sometimes form mixed flocks with Tree, Cliff and Barn Swallows.

Identification

Adult Male (spring/summer)

 

The male Bank Swallow has dark brown upper parts and is white underneath; its white throat wraps around its dark brown auriculars, and the dark brown breast band is quite distinctive; the tail is long and notched.

Adult Female (spring/summer)

Male and female are similar in plumage.

Juvenile

The juvenile looks strikingly similar to the mature adult, save for some buff-tipped feathers on its back.

General Information

General:

Small slender swallow. Length: 13.00-13.50cm. Wing: 33cm. Weight: 13.5grams.

Behaviour:

An aerial insectivore, these birds feed almost exclusively on insects, and any vegetable matter found it their diet was most likely eaten by accident! Amazingly, the Bank Swallow also drinks on the wing, flying low over the water, skimming the surface with its lower mandible.

Habitat:

The Bank Swallow adapts well to its environment and can be found anywhere from sea level up to 7000 feet! These birds are often found in open areas such as a lake, river, marsh, an open meadow or farmland. During migration, it tends to follow rivers and coasts as it heads south.

Information:

The Bank Swallow is a cavity nester, building its home in an earthen embankment, sometimes up to 5 feet deep! It also nests colonially, sometimes up to 2000 birds at one site. Both the male and female excavate a tunnel, which turns upward as it goes in (to prevent flooding) and has a larger chamber at the end for incubating the eggs. A typical clutch has anywhere from 3-6 white eggs, which are incubated for about 2-3 weeks.

Similar species:

Tree Swallow.

Conservation Status:

The Bank Swallow presently holds a status of Least Concern, but in truth, population trends are difficult to follow, due to the frequency it must change nesting locations. Over the past three decades, several bird surveys (such as the CBC) have recorded a decline, but others appear stable. Urban development along rivers and flooding control projects destroy breeding colony locations and yet, like other swallow species, this bird has adapted to human activity and readily makes use of quarries and gravel sites for nest.

Maps & Statistics

Capture Rates

Bank swallows are a rare species in Vancouver and captures at the VARC banding station have been limited to a single individual.

Ageing and Sexing (Band Size: 0, 1)

Molt Summary:

PF complete (Sep-Apr), PB AHY complete (Aug-Mar); PA absent. Most molting occurs on the winter grounds.

AHY/ASY (Apr-Mar): Feathers of the upperparts , wing covs, and terts without pale edging; chin and throat white; unreplaced flight feathers relatively worn.

Sex: M=F by plumage; CP/BP (Apr-Aug); a partial BP can develop in males.

Juvenile/HY/SY

MAY - MARCH

Juv: has feathers of the upperparts edged buffy and a buffy pinkish wash to the throat. Juv M=F

HY/SY: Feathers of the upperparts , wing covs, and terts edged with buff or whitish; unreplaced flight feathers relatively fresh; chin and throat washed pinkish, sometimes with faint, dusky spotting.

AHY/ASY

APRIL - MARCH

Feathers of the upperparts, wing covs. and tertials without pale edging; chin and throat white; unreplaced flight feathers relatively worn in Jun-Mar

Sex: M = F

CP/BP (April – August); a partial BP can develop in M