Common Name: Tree
Species: Hirundo rustica
photo Ivan Andrijevic
The Tree Swallow is a member of the order
Passeriformes, which consists of perching birds. It is a
member of Hirundinidae, the swallow and martin family.
The species modifier, bicolor, translates as “two
colors,” a reference to the two solid, contrasting
colors of its back and belly.
A Tree Swallow measures 5-6 in from head to tail (12-15
cm). Wingspan measures 12-14 in (30-35 cm). A Tree
Swallow weighs between 0.56 and 0.88 ounces (16-25 g).
There is a small fork present in the tail. Both male and
female Tree Swallows have a dark blue-green back and a
pure white belly. Juveniles have a grayish brown back
with a dull white belly.
The summer range of the Tree Swallow extends from the
central portions of the United Sates up through Alaska
and throughout Canada. Their winter range runs from the
southern portions of the United States to Central
America. Tree Swallows can be found in open lands near
water. They live in places such as meadows, marshes,
grasslands, wooded swamps, shorelines, and rivers.
Tree Swallows are aerial insectivores. They forage for
flying insects, such as mosquitoes, while in flight, but
they also search the ground for other insects and
spiders. Tree Swallows also occasionally eat berries and
Tree swallows are polygamous. They live in loose
colonies, where the males maintain small territories.
Males arrive at the breeding ground a week before the
females do in order to establish these territories.
Males may flutter, bow, or sing to attract females.
The nest is made by the female, although the male may
help to gather materials. The nest is a cup shaped
structure made out of grasses and pine needles. Tree
Swallows roost in snags, or dead standing trees, nest
boxes, and tree cavities. Female Tree Swallows lay
between two and eight eggs. Females are the only
incubator, and they have been known to abandon their
nests for a few days. After two weeks, the eggs hatch.
Both parents feed the young until they fledge, which can
be anywhere from sixteen to twenty-four days.
Tree Swallow songs are a series of liquid
twittering that resemble the sound of a bubbling brook.
Where to see them in WNY
Tree swallows are found in open
meadows, near rivers and lakes, and also in marshes. A
good place to find them is the Iroquois National