General
Cerulean Warbler: Small warbler with sky-blue, faintly streaked upperparts and black-streaked white flanks. Black band separates white throat and belly. Wings have two bold white bars. Female has unstreaked, blue-gray upperparts, yellow wash on face and breast, pale streaks on flanks, and yellow eyebrows.
Range and Habitat
Cerulean Warbler: Breeds from extreme southwestern Quebec and southern Ontario west to Minnesota and Nebraska, and south from eastern Kansas to South Carolina. Spends winters in montane forests of northern South America. Prefers mature forests with broad-leaved, deciduous species and an open understory; often found near bottomlands and rivers.
Breeding and Nesting
Cerulean Warbler: Three to five brown-spotted, white to gray eggs are laid in nest made of bark strips, grass, spider silk, and lichens, and lined with moss and fur. Nest is built by the female and built 15 to 90 feet above the ground, usually on a horizontal branch in a deciduous tree. Incubation ranges from 12 to 13 days and is carried out by the female.
Foraging and Feeding
Cerulean Warbler: Feeds on insects, with a preference for caterpillars; usually forages in trees.
Vocalization
Cerulean Warbler: Male gives rapid buzzing notes on one pitch followed by a short series of rising and accelerating notes, ending with a high buzzing trill: "zhee-zhee-zhee-zizizizi zzzeeeet."
Similar Species
Cerulean Warbler: Male is distinctive. Female and juvenile are distinguished from other warblers by gray (not olive) backs, strong white wing-bars, and distinct white band above eye.