The
Bank Swallow is a small, slender song bird. In its typical adult appearance,
the bird is white on the underneath and brown on top of its feather coat, with
a dark band running across and extending all the way down to the middle of its
chest. It has a small bill and supports long wings of about 25-29 cm which help
it during flight. They are usually 12-14 cm in length, and weigh around 10-19
grams. Traditionally, Bank Swallows nest in colonies along the streamside banks
of North America, but they can also be found across Europe and Asia. The
British name for Bank Swallows is Sand Martin and is commonly used across
Britain; other Spanish and French names for the bird are also commonly used in
the respective countries.
Since
they live in low areas mostly around rivers, streams, ocean coasts or
reservoirs, the territories they are found in are vertical cliffs or banks.
Here they nest in colonies which include up to 20,000 nests. In the past, Bank
Swallow bird was commonly found around natural bluffs or on the streamside.
However, with the seemingly increased eroding, the Bank Swallows have
re-located their colonies to more man-made sites like quarries made out of sand
or gravel, or road cuts. These locations offer the same support as a vertical
cliff and allow for stability of their nests. As you can see in bank swallow
pictures, these nests are very carefully made and placed. Each nest is made in
such a way that it forms a chamber. The male member uses his small, cone shaped
bill along with feet and wings to dig burrows which are perpendicular to the
ground level and go about 25 inches into the side of the banks. These burrows
eventually lead to the nest chamber, as the male widens them upwards and from
both sides in such a way that constant temperatures can be maintained inside
the burrow. Then the female member builds the nest by constructing a mat of
straw, grasses, leaves, or rootlets that she collects from around the banks.
This mat is 1 inch thick and 5 inches in diameter to offer support and firmness.
Since the Bank Swallows make nests in large colonies, they do it around fairly
loose soils so that it is easy to burrow in. Similarly, these areas are located
near water bodies so that there is vertical space for the birds to fly. It is
one of the interesting bank swallow facts that every individual chooses a
colony first, then a nest location within that colony area. Interestingly, it
is the male that digs the burrow before it has a mate. It is only then that a
female hovers itself over the burrow she chooses and then mates with the male
in that nest site. The Bank Swallows carefully choose a location that is in the
upper third part of the bank so that few ground predators can attack them. They
mostly eat insects like bees, wasps, ants, butterflies or moths. Since they
live near water, it is easy for the Bank Swallows to catch food. They fly at a
height of about 50 ft above open water or ground and catch insects, and then
feed either singly or with large groups from their colonies. Bank
Swallows have a set of distinctive behavior that instantly distinguishes them
from other such bird species. These include the seemingly different pattern of
flying with shallow, fluttery wing beats. They glide for 2 seconds but have a
less twisty and straighter flight than other Swallows. Bank Swallows are
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