Adult: Has a yellowish-buff eyebrow and brown streaking from chin to breast and on the flanks. The dorsal side is brownish color. Has brown colored eye stripe and lore.
Immature: Tail feathers are tapered.
FOOD: eats insects, mollusks, crustaceans, and small fish in the summer (Ehrlich et al., 1988). In winter eats mostly insects (Ehrlich et al., 1988).
MATING SYSTEM: monogamous (Ehrlich et al., 1988).
BREEDING SYSTEM:
Where Breeds: Breeds in swamps or boggy areas, or by streams or pond edges (Baicicich and Harrison, 1997).
Nest: The nest is found in a cavity, a hollow among roots of a fallen tree base, in a bank, among tree-roots, or in the side of a decayed stump, and is raised above water (Baicicich and Harrison, 1997). The nest is a cup made of moss, decayed leaves, bark strips, rootlets, small twigs, and pine needles (Baicicich and Harrison, 1997). The nest is lined with fine grasses, hair, or fruiting moss stems (Baicicich and Harrison, 1997). The nest is built by the female (Baicicich and Harrison, 1997).
Breeding Season: The breeding season begins in late May in the South of the range and in early June in the north of the range (Baicicich and Harrison, 1997). The breeding season ends in late July (Baicicich and Harrison, 1997). This species is single-brooded (Baicicich and Harrison, 1997).
Eggs: There are between 4 and 5 eggs laid in a clutch (Baicicich and Harrison, 1997). The eggs are subelliptical to short subelliptical in shape and creamy-white, buffish, or yellowish-white in background color (Baicicich and Harrison, 1997). The eggs are speckled reddish-brown to brownish-gray and is sometimes clouded or scrawled with brown (Baicicich and Harrison, 1997). The heavier markings are concentrated at the larger end (Baicicich and Harrison, 1997). The average size of an egg is 19 X 13 mm (Baicicich and Harrison, 1997).
Incubation: The incubation period lasts from 12 to 13 days and is done by the female (Baicicich and Harrison, 1997). The incubation period starts with the next to last egg laid (Baicicich and Harrison, 1997).
Nestling: The young are born altricial and downy, with the down being dark olive-brown in color (Baicicich and Harrison, 1997). The mouth is red and the gape flanges are yellow of the young (Baicicich and Harrison, 1997). The young fledge from the nest after 10 days and are tended by both parents while in the nest (Baicicich and Harrison, 1997). The parents feed the young for 2 weeks after they fledge from the nest (Baicicich and Harrison, 1997).
MIGRATION STATUS IN WISCONSIN:
The northern waterthrush is a neotropical migrant.
REFERENCES:
Baicicich, P.J. and Harrison, C.J.O. 1997. A Guide to the Nests, Eggs, and Nestlings of North American Birds, 2nd edition. Academic Press: San Diego.
Ehrlich, P.R., Dobkin, D.S., and Wheye, D. 1988. The Birder’s Handbook: A Field Guide to the Natural History of North American Birds. Simon and Schuster, Inc.: New York.
Stokes, D.W. and Stokes, L.Q. 1996. Field Guide to Birds: Eastern Region. Little, Brown and Co.: Boston.
