The cerulean warbler is a small songbird in the family Parulidae. It is a long-distance migrant, breeding in eastern North American hardwood forests. In the non-breeding season, it winters on the eastern slope of the Andes in South America, preferring subtropical forests.
Region
Eastern North America and Northern Andes
Typical Environment
Breeds in large tracts of mature hardwood forests across the eastern United States and southern Canada, with strong centers in the Appalachian region and the Mississippi/Ohio river valleys. Prefers the upper canopy, especially in tall oaks, maples, and tulip poplars with a semi-open canopy structure. During migration it follows riparian corridors and forest edges. In the non-breeding season, it winters on the eastern slope of the Andes from Venezuela and Colombia south to Ecuador and northern Peru, using subtropical and premontane forests and shade coffee agroforests.
Altitude Range
0–2000 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 1/5
Males show striking sky-blue upperparts and sing from the high canopy, making them easier to hear than see. The species has declined due to loss and fragmentation of mature deciduous forests on the breeding grounds and subtropical montane forests on the wintering grounds. It often uses shade-grown coffee and mixed-species flocks in the Andes during winter.
Adult male Cerulean warbler close-up, showing "necklace" and streaking
Female cerulean warbler in the nest
Cerulean warbler eggs
"Azure Warbler" in Birds of America
San Vicente Migratory Bird Festival
Temperament
active canopy specialist, somewhat secretive
Flight Pattern
short rapid wingbeats with agile, darting movements in the canopy
Social Behavior
Monogamous during the breeding season; males defend high-canopy territories and sing persistently. Nests are open cups placed high on horizontal branches of deciduous trees. In winter it often joins mixed-species flocks with tanagers and other warblers.
Migratory Pattern
Seasonal migrant
Song Description
Male song is a buzzy, accelerating series that rises in pitch and ends with a distinctive higher, emphatic note. Calls are sharp chips given during foraging and agitation. The song carries well from the canopy despite the bird’s small size.
Plumage
Male has sky-blue upperparts with dark streaking, white underparts, and a thin bluish-black breast necklace with streaked flanks; two bold white wing bars. Female is bluish-green above and yellowish-white below with weaker streaking and similar wing bars. Both sexes show a clean white belly and relatively short tail with white edges.
Diet
Primarily consumes caterpillars, beetles, leafhoppers, and other small arthropods gleaned from leaves and twigs. Often hover-gleans from the underside of leaves and occasionally sallies to catch flying insects. May take small berries incidentally during migration when insect prey is scarce.
Preferred Environment
Feeds mostly in the mid to upper canopy of mature deciduous forests on breeding grounds. During migration and winter, forages in forest edges, secondary growth, and shade coffee at mid-elevations, still favoring upper foliage layers.
