A medium-sized wood warbler. Total length about 12 cm. Body mass about 9 g. Boldly patterned plumage of yellow, black, and olive green. Breeding male distinctive, with bright yellow stripes bordering black cheek patch. Crown and throat black; yellow extends below throat to lower breast; remaining underparts white; sides and flanks streaked black. Back olive green, with distinct black streaks or spots. Two white wing-bars, and extensive white in outer tail-feathers. Adult female differs from male in that female has generally duller markings and coloration, crown is olive green with thin black streaks, cheek-patch is deep olive, not black, throat is yellow and has variable amount of black markings, and back has lees distinct black streaks than male (Wright et al. 1998). See Condor 94:490-501 for aging criteria.
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.
Western Hemisphere Range
Tall coniferous and mixed coniferous-deciduous forest at various elevations, from wet coastal forest at sea level to dry subalpine forest. Most abundant in unlogged, old-growth forest, but also common in late successional stages. Uncommon in logged forest (Wright et al. 1998).
Insects. Honeydew excreted by scale insects in low-latitude cloud forests (Wright et al. 1998).
Nests located almost exclusively in coniferous trees; most reported in spruce and fir. Nest is a bulky open cup. Eggs are ovate, ground color is white with slight gloss and marked with various browns. Clutch size ranges from 3 to 7 eggs (Wright et al. 1998). Statewide, nests from late May through July.