American Tree Sparrow

Spizella arborea

Order PASSERIFORMES - Family EMBERIZIDAE

Menu

1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

The American Tree Sparrow is a common winter visitor in backyards all across southern Canada and the northern United States. Despite its common name, it forages on the ground, nests on the ground, and breeds primarily above treeline in the far North.

Cool Facts

• During the summer, the American Tree Sparrow eats nearly 100% animal matter (mostly insects). In the winter it eats none, turning then to eating entirely seeds and other plant foods.
• As in most birds, the American Tree Sparrow is sensitive to changes in day length, which influence the growth of the sex organs. Increasing day length in late winter causes the gonads to grow. This sensitivity to light is independent of vision. Blind tree sparrows in captivity still show normal patterns of gonadal growth when kept in the proper light conditions.

• No one knows just how many American Tree Sparrows exist. But they breed across a vast expanse of northern Canada and Alaska, approximately 100 million hectares (247 million acres). If the area is about 10-20% filled by tree sparrows, and they have 1-ha territories, as is the case near Churchill, Manitoba where they have been well studied, then approximately 10 to 20 million pairs should be breeding.

• A study found that the American Tree Sparrow seems to prefer to look for predators out of its left eye. This preference may be because the right hemisphere of the brain is dominant for processing visual information. Oddly, the Dark-eyed Juncos examined in the same study preferred to look out of their right eyes.

Description

• Size: 14 cm (6 in)
• Wingspan: 24 cm (9 in)
• Weight: 13-28 g (0.46-0.99 ounces)

• Small songbird.
• Rusty brown crown and eyestripe on gray head.
• Dark spot in center of unstreaked breast.
• Two white wingbars.
• Tail rather long.

• Upper bill dark gray, lower bill yellow.
• Rusty brown back with dark streaks.
• Buff sides tinged with rusty brown.
• Belly gray.

Sex Differences

Sexes alike.

Immature

Juvenile like adult, but with some streaks on crown, nape, and breast.

Similar Species

• Chipping Sparrow smaller, without dark central chest spot, and a black (not rusty) stripe through the eye. Chipping Sparrow has brown crown with faint streaks in winter. Go here for more on distinguishing these two species.
• Field Sparrow has pink bill, distinct eyering, and lacks spot on chest.
• Song Sparrow has streaks on chest as well as central spot, and dark mustache marks.
• Lark Sparrow has bold face pattern and white on outer tail feathers.

Sound

Song a series of thin, high, sweet whistled notes. Call a hard "tseet."

»listen to songs of this species

Range

Summer Range

Breeds from western Alaska to Labrador, southward to northern British Columbia and Quebec.

Winter Range

Winters from southern Canada southward to northern Arizona, northern Texas, and South Carolina.

Habitat

Breeds in open scrubby areas near treeline. Winters in fields, marshes, gardens, open forests, and residential neighborhoods.

Food

Seeds, berries, and insects.

Behavior

Foraging

Feeds on ground or in low shrubs.

Reproduction

Nest Type

Open cup of moss, grasses, shreds of bark and twigs, lined with fine grass and feathers (usually from a ptarmigan). Placed on or near ground, often in tussock of grass at base of shrub.

Egg Description

Pale blue with reddish speckling.

Clutch Size

4-6 eggs.

Condition at Hatching

Helpless with sparse tufts of brownish gray down.

Conservation Status

Common. Remote breeding areas little affected by people. Uses human-modified habitats readily in winter.

Other Names

Bruant hudsonien (French)

Sources used to construct this page:

1. Franklin, W. E., III, and S. L. Lima. 2001. Laterality in avian vigilance: Do sparrows have a favourite eye? Animal Behaviour 62: 879-885.
2. Naugler, C. T. 1993. American Tree Sparrow (Spizella arborea). In The Birds of North America, No. 37 (A. Poole, P. Stettenheim, and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.