The Northern Waterthrush is a member of the Warbler family with a body plan more similar to that of a thrush, albeit smaller. It is brown in the upperside, with brown streaks on a white belly. It has a white superciliary and flecking on the throat. The very similar Louisiana Waterthrush has a wider superciliary, with a white throat. Both species are terrestrial, with the Northern preferring slower moving streams and edges of ponds. Both species teeter their body as they move around. They are both migrants that occur in Costa Rica mainly from mid August to mid May, with the Northern being the most widespread and commonly seen in the territory.