Oer: Passeriformes; Family: Hirundinidae
The Tree Swallow is a small, glossy dark blue-green to dull dark brown bird with evenly white undersides, a short bill, long pointed wings, and a slightly forked tail.
It lives on farms, by swamps, and in open grassy areas, especially near water, swooping and gliding through the air to catch insects in flight or on the water's surface. In cold weather, when insects are scarce, it can eat seeds and small fruits.
It gets its common name from the fact that, unlike other swallows, which nest in stream banks, under bridges or in buildings, this species usually nests in holes in dead or living trees. It will also use nest boxes, such as those made for bluebirds.
The white eggs, laid in a nest composed of twigs, grasses, pine needles and feathers, are incubated by the female bird alone; the male helps to feed and protect the young.
Tree swallows also do not nest in colonies, as some other local swallows do, so lack the protection of the group. Nevertheless, they will fly at other birds and intruders near the nest. On the other hand, when migrating to, and staying in, the southern US, the Caribbean or Central America for the winter, they join in large flocks.
They are reported to use at least 14 different calls to communicate with each other.