Northern Waterthrush ID, here's how!

Northern Waterthrush, one of the early migrant warblers, on Sanibel, FL Pond Apple trail yesterday. I heard it call and photographed it. People get confused about waterthrush ID. Here is why it is a Northern Waterthrush. It is yellowish buff below (Louisiana is cream colored below) with a streaked throat (Louisiana usually does not have streaks on throat) and a evenly colored buff eyebrow (Louisiana has bicolored eyebrow with buff in front and white above and behind the eye). Dark heavy elongated dashes on this bird are arranged into streaks on underparts (Louisiana’s medium brown dashes form blurred loose streaks on underparts). Eyebrow thickness and length not always a reliable clue. The legs were pinkish (Louisiana’s are bubble gum pink) and this bird was bobbing the tail not whole end (Louisiana bobs whole rear end in often a circular motion).

Here is some additional information,

Comparison Tips from our Stokes Field Guide to Birds of North America national field guide, page 629.

“Start with shape and behavior. Louisiana is bigger, more elongated, with larger bill; tail extends less past undertail coverts than Northern’s. Louisiana bobs tail (often in a circular manner) and more of rear end than Northern. Northern’s eyebrow solid yellow or solid white; Louisiana’s is bicolored, with buff in front, white above and behind eye. Length and thickness of eyebrows not always a reliable clue, since individual’s vary greatly. Northern’s throat usually with fine streaks; Louisiana’s usually clear white. Northern is white or yellowish buff below with heavy dark streaking, sometimes pale buff-brown on flanks; Louisiana is creamy white below with somewhat paler streaking and yellowish or salmon wash on flanks. Louisiana’s legs are brighter pink than Northern’s. The two species songs are distinct; their call notes are quite similar."