Spizella arborea
If you wanted to let the activities of birds guide your yearly calendar, there might be no better subject to follow than the American Tree Sparrow. With its unassuming but doggedly regular migratory habits, this species quietly announces the arrivals of spring and fall. The gentle flow of the American Tree Sparrow through the Rockies usually frames the emergence of willow leaves, and it is rarely seen perched atop anything but bare branches. While both its common and scientific names (arborea means 'tree') might imply that this is a forest-dwelling bird, tree sparrows are most often found in semi-open areas. As an Arctic-nesting bird that prefers bushes to trees, perhaps a more appropriate name would be 'Arctic Shrub Sparrow.' |
I.D.: Sexes similar: pale rufous cap; unstreaked breast; dark, central breast spot; gray face; soft gray underparts; mottled brown upperparts; dark legs; dark upper mandible; light lower mandible. Size: L 51/2-61/2 in. (14-17 cm). Range: uncommon migrant and winter visitor in the Colorado, Utah, Wyoming and Montana Rockies; rare migrant elsewhere in the Rockies. Habitat: brushy thickets, roadside shrubs, semi-open fields and agricultural areas in the lowlands. Nesting: typically along the arctic tundra-taiga transition zone; usually on the ground; often on a raised tussock or other dry area; small cup nest is woven with grass, moss and bark shreds and lined with feathers and fur; female incubates 3-5 eggs for 12-13 days. Feeding: scratches exposed soil or snow for native plant seeds and occasionally insects; occasionally visits feeding stations during migration and winter. Voice: sometimes practices its breeding song before departing for the Arctic: tseet notes followed by a warble or trill. Similar Species: Chipping Sparrow: clear black eye line; white eyebrow; lacks the central breast spot. Swamp Sparrow: lacks the central breast spot and white wing bars. |