I photographed this waterthrush on the 12th of May, 2016, in a suburb to the west of Toronto. At the time, I put it down as a Northern, chiefly because the supercilium didn't broaden at the rear, as I believed a Louisiana Waterthrush's should. Louisiana Waterthrush is also considerably rarer than Northern in southern Ontario. I've been going over my old photos, however, and now that I take a second look at these, I wonder if it isn't a Louisiana after all. I've since read that the supercilium doesn't necessarily get broader at the rear on a Louisiana, and several of the bird's other features look better to me for Louisiana than Northern – in particular, the pattern and density of the streaking on the breast and sides. Comparing my photos to Sibley's illustrations here, the streaking pattern certainly looks closer to that of a Louisiana Thrush. There are a couple of dark spots on the throat, but Sibley says that "some Louisianas have scattered small dots over throat", so that doesn't seem to eliminate a Louisiana Waterthrush as well.
The habitat was a downed willow tree in fairly dense undergrowth immediately next to a fairly broad creek, in a deeply eroded valley. It isn't an area where either waterthrush is known to breed.
So, is this a white-bellied, sparsely-streaked Northern, or a Louisiana with a weak supercilium?
The habitat was a downed willow tree in fairly dense undergrowth immediately next to a fairly broad creek, in a deeply eroded valley. It isn't an area where either waterthrush is known to breed.
So, is this a white-bellied, sparsely-streaked Northern, or a Louisiana with a weak supercilium?