Cerulean, azure, cobalt, indigo, navy, sapphire, beryl… There are many shades of blue, but when you spot this week’s featured bird, you’ll feel anything but the blues! Meet the lovely and lively cerulean warbler.

Cerulean Warbler – Photo by Ed Schneider

Name: Cerulean Warbler
Scientific Name: Setophaga cerulea
Scientific Family: Parulidae

Habitat: These spritely warblers prefer to stay high in deciduous forest canopies, typically with open understory layers that aren’t too lush or dense. Riparian habitats, wet river valleys and even dry slopes with suitable mature vegetation are all agreeable for cerulean warblers.

Range: These birds are neotropical migrants that breed in the eastern and central United States, as well as in southern Ontario, during the summer. They may be spotted as far west as eastern Minnesota, Iowa, Missouri or even northern Arkansas. In winter, these birds migrate to higher elevation forests in South America, stretching from northern Venezuela to the Andes Mountains through central Peru and into western Bolivia.

There’s no mistaking the delicate cerulean shade of the male cerulean warbler, with his blue upperparts, shoulders and head, blue-black streaking on the flanks and thin blue necklace. In contrast, the throat and abdomen are plain, bright white. The tail is blue-black, and the wings show two white wing bars. Females are much less blue overall, and instead have more camouflaged olive-green or faintly blue-green tones to their plumage, with a faint yellow or buff wash on the throat and underparts. There is a bit of blue tint on the crown and tail, however, and a broad buff eyebrow is distinctive. Like males, females also have two white wing bars.

These beautiful warblers are difficult to see, not only because of their tiny size and how they stay hidden high in tree foliage as they flitter about gleaning insects, but also because of severe population declines in both their summer and winter ranges. Because these birds require tall, mature trees, they are particularly vulnerable to development and agricultural practices that remove forests. They are also at risk from brood parasites such as the brown-headed cowbird, which can dramatically impact nesting success. While these birds are not yet officially classified as threatened or endangered, that status may change as more thorough population surveys accurately document their falling numbers.

Shade-grown coffee plantations are vital to protect these birds in their winter range, as are protecting larger tracts of suitable forest in the summer breeding range. With care and protection, these birds can thrive again and will lift the blues of every birder who spots them.