Medium-sized 12 to 13 cm, 9 to 11 g. Plumage more extensively yellow than most other wood-warblers. Face, throat, and remaining underparts bright yellow, variably streaked with chestnut below throat. Upperparts yellow-green to olive with wing feathers edged yellow. Dark eye stands out on relatively unmarked face. Rather short-tailed (Lowther et al. 1999). See Kaufman (1991) for detailed information on identification. See Wiedenfeld (1991) for information on geographical variation in male morphology.
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
In Bozeman area, normal migration periods are May 15 to June 5 and August 15 to September 5.
Found throughout much of North America in habitats categorized as wet, deciduous thickets. Found especially in those dominated by willows (Lowther et al. 1999).
Main foods include insects and other arthropods. May take wild fruits occasionally (Lowther et al. 1999).
Near Fortine, egg dates range from June 7 to 30. Statewide, nesting is from early June into July.