Daily Bird nesting season special: Louisiana Waterthrush and Northern Waterthrush
June 24, 2022
by Greg Hanisek, editor, The Connecticut Warbler
These warblers are active, vociferous birds, habitual tail-waggers easily told from our array of other warbler species. Telling them apart is another matter.
Habitat is a key to sorting out the waterthrushes, because their habitat preferences are quite different.
In Connecticut, Louisiana Waterthrushes breed almost exclusively along fast-moving streams. They inhabit some of our most picturesque locales, such as clear, cool brooks tumbling through hemlock glens. Since the bulk of their range stretches to our south, we don’t see a lot of them on migration, a time when birds sometimes stray from favored habitats. As a result almost all observations are of birds in breeding spots.
Northern Waterthrushes prefer still water locations such as swamps and bogs. They migrate through Connecticut in good numbers to breeding grounds to the north. The eBiird map for June shows reports scattered through Connecticut except for the coastal towns, where there are no reports.
The two species’ songs are the best way to identify waterthrushes. They both have similar loud chip notes, but their songs are distinctive. Words can’t do them justice, so it’s best to listen to them.
Here’s the song of the Northern Waterthrush.
Waterthrushes look very similar. That’s why their songs are so important. A lot of the visual differences are relative, but here’s a rundown of things to look for (preferably in combination) to ID a silent bird:
Bill – larger on Louisiana.
Throat: Mostly clear on Louisiana; with fine streaking on Northern.
Supercillium (eyebrow): On Louisiana, buff in front of eye, white and widening behind eye; on Northern more even color and width.
Flanks: On Louisiana, salmon-buff; on Northern, little or no contrast with rest of underparts.
Louisiana Waterhrushes arrive early — in April and even late March — and start to leave by late July. Northern Waterthrushes arrive and start to depart about a month later.
Neither species is considered at high risk, but both are subject to all the concerns about habitat loss and degradation associated with neotropical migrants.