On the winter grounds, the bird consumes a greater variety of food, adding minnows and decapod crustaceans to its diet. The Northern Waterthrush forages alone using such tactics as twig gleaning, flycatching, hovering, chasing, and a lot of pecking. Microhabitats for foraging include water, ground, foilage, and air. Reproduction Pair bonding begins immediately after the female arrives on the breeding site. Males perch in trees that are standing near water while females are below usually feeding along the edge of the water.
Males vibrate their wings and raise their crown feathers and sing.
The female may answer with a chink. The pair bond is broken shortly after successful fledging. The male selects the general area of the nesting site, but the female chooses the actual nest site. Nests are usually in the cavity of a root system of wind-blown trees in a wooded swamp, on the side of a fern clump or under cover along the banks of a lake or a river. There is typically covering above the nest and an opening to one side.