Nesting Behavior
American Tree Sparrows breed in shrubby habitat
along the edges of the tundra and northern tree limit. The nest
of grass, weeds, feathers and hair, built by the female, is
usually placed on or near the ground at the base of a small
tree, shrub or tuft of grass. From 3 to 5 eggs incubated by the
female hatch in about two weeks. Both parents care for the
young, who leave the nest in 9 to 10 days.
Banding Recoveries
The Bird Banding Lab web site reports that
between 1955 and 1997, a total of 404,923 American Tree Sparrows
were banded. Of these, 12,751 have been recovered, a recovery
rate of 3.14%.
Banding studies show that the American Tree
Sparrow can live from 6 to 9 years in the wild. They are short
to long distance migrants that winter across most of the USA,
and migrate from 1,500 to 3,000 miles to their breeding grounds
in Alaska and northern Canada.
If you should recover a banded bird, please report the band
number to the Bird Banding Lab by calling 1-800-327-BAND.
Economic Importance &
Conservation Status
Populations of American Tree Sparrows seem to be holding
steady but declines are being noticed in some wintering regions.
Their Northern breeding habitat is not as impacted by man’s
activities as are their wintering grounds.
In addition to the many weed seeds consumed, diet consists of
flies, beetles, ants, grasshoppers, other insects and spiders.
These small birds are well adapted to winter habitats and do
well in temperatures down to minus 28 °C as long as they can
obtain food. Weedy fields left unmowed are important source of
food and cover for Tree Sparrows and many other species,
especially when snow covers the ground. |