Birds
Prothonotary Warbler
Protonotaria citrea · also called golden swamp warbler
A brilliant golden-yellow bird disappears into a tree cavity rising directly out of still swamp water, a nesting choice no other warbler in the eastern United States makes, earning the prothonotary warbler its memorable nickname, the swamp canary.
Overview
The prothonotary warbler, Protonotaria citrea, is a vividly coloured songbird native to flooded bottomland forest and swamp habitat across the southeastern and central United States. Its unique cavity-nesting habit among eastern warblers, striking golden-yellow plumage, and willingness to accept artificial nest boxes make it one of the more visually and behaviourally distinctive warblers in its range.
A warbler that nests like a woodpecker
While every other eastern warbler builds an open nest in a shrub, tree, or on the ground, the prothonotary warbler alone claims a cavity over water, a habit that ties its fortunes directly to the availability of standing dead trees in flooded forest.
Status
Least Concern overall, though declining somewhat in parts of its range as mature flooded forest with suitable nest cavities is lost, a decline partly offset by nest box programs in some areas.
Prothonotary Warbler: common questions
Why is the prothonotary warbler called the "swamp canary"?
This species shows a strikingly vivid golden-yellow head and underside, a colour intense enough to draw comparison to a canary, combined with its close association with swamp and flooded forest habitat, which together gave rise to the nickname "swamp canary" alongside its more formal alternate name, golden swamp warbler.
Why is the prothonotary warbler unusual among eastern warblers?
This species is the only warbler in the eastern United States that nests inside natural or artificial cavities, typically positioned over or very near standing water, a nesting strategy no other eastern warbler shares, since most build open cup nests in shrubs, trees, or on the ground instead.
Do prothonotary warblers use nest boxes?
Yes, this species will readily accept artificial nest boxes placed over or near water, and conservation programs in some areas have installed nest boxes specifically to support local breeding populations, taking advantage of the species' willingness to use artificial cavities in place of natural ones.
What does the prothonotary warbler's song sound like?
The male produces a loud, clear, ringing song often rendered as a repeated "sweet sweet sweet sweet," a simple but distinctive and far-carrying song that helps announce the bird's presence across open swamp and flooded forest habitat even when the bird itself is hard to spot.