Montana Field Guide

Length is 13 cm. Male is glossy black with bright orange patches on the sides, wings, and tail; belly and undertail coverts are white. Female is gray-olive above, white below with yellow patches. Immature resembles female. By first fall, young male's patches show some salmon; by first spring, breast has some black spotting; full adult male plumage is acquired by second late summer. Often fans tail and spreads wings when perched, making the colorful patches conspicuous. VOCALIZATIONS: Variable song, a series of high, thin notes usually followed by a wheezy, downslurred note. NEST: a firm, compactly woven cup of plant down, bark fibers, small rootlets, grass stems; lined with fine grasses, weed stems, hair, sometimes feathers; decorated on outside with lichens, birch bark, bud scales, plant down; bound with spider silk; built entirely by the female, typically requiring 1 week or more (but sometimes less than this). Outside diameter 2.75 in (7 cm), height 3 in (7.6 cm); inside diameter 1.75 in (4.4 cm), depth 1.5 in (3.8 cm). EGGS: Average size 16.2 x 12.3 mm. Oval to short-oval. Shell smooth, has slight gloss. White, grayish white, creamy white, greenish white; dotted, spotted, blotched with reddish-browns, grays; often concentrated at large end.

For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.

Adults are easily distinguished from other species. Nest is similar to that of Yellow Warbler (Dendroica petechia) but has neater construction and thinner walls. Also similar is the nest of American Goldfinch (Carduelis tristis), but this is wider than high, whereas the American Redstart's is higher than wide (Harrison 1975).

In Bozeman area normal migration periods are from May 20-Jun 1 and Aug 25-Sep 10.

Species prefers second growth, deciduous woodlands usually near water. Often found in shrubby areas, along with alder and willow thickets.

Diet consists mainly of insects. In late summer months, small berries and fruits. Usually forages alone or near other American Redstarts.

20 types of songs were described. No significant associations were found between use of a particular song type and other variables (time, location, behavior). Songs sung in dense green vegetation had lower pitch.

Statewide, young reported out of nest as late as August 5. Near Fortine, egg dates range from June 12 to July 10.