Some scientists think that habitat loss—on both the breeding and wintering grounds—could be adversely impacting this warbler.
Cerulean warblers were far more numerous in pre-settlement America than they are today. Their principle habitat is large tracts of upland oak-hickory forest, and they occur in greatest numbers where the forest canopy is uneven due to various ages of trees in close proximity.
Thus, modern logging practices, which often produce large-scale, even-aged timber stands, probably have negative effects on cerulean warblers.
Be sure to become acquainted with the cerulean warbler’s buzzy, ascending song, as these birds rarely leave the upper canopy forest, and require a bit of effort to see.