|Species: Bank Swallow
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
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.
The Bank Swallow is
just over 5 inches long, and weighs around 14 grams. It has a small
black bill, long pointed wings, and a long tail but shallowly
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.
Adult Female: Both
the male and female look identical and are best distinguished by a
brood patch or a cloacal protuberance.
The juvenile look strikingly similar to the mature adult, save
perhaps for some buff-tipped feathers on its back.
The Northern Rough-winged Swallow is a lighter brown colour, does
not have the contrasting breast band, and white does not wrap around
its auriculars. Immature Tree Swallows look very similar, and may
have a faint breast band, but it is much less distinctive than the
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
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.
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.
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 nests.