Males have a black head with a conspicuous, somewhat triangular white patch; black back and wings; white patches on the wings; white chest; pale brown underparts; and a black tail. Females are mottled brown overall, with a black back and wings, white patches on the wings, and paler underparts. 46 cm (18 in) in length. Both the male and female have a puffy, rounded crest which flattens out when they are flying. The bill is long, thin, and serrated.
The breeding season begins in mid-February, peaks in March, and extends to late April. Breeding habitat consists of areas with slow-moving water (such as lakes, ponds, streams, swamps, and marshes) associated with forested areas. The nest is in a cavity of a snag or tree usually 15-20 feet above the ground. This species will sometimes use nesting boxes placed for Wood Ducks. The nest is built within the material found in the cavity and is lined with down and other feathers. The female lays 7-13 (usually 10-12) eggs that she incubates for 32-33 days. The young are precocial and are cared for by the female. The young first fly at 71 days after hatching.
Non-breeding habitat includes the same areas used in the breeding season and also more open bodies of water. The diet of the Hooded Merganser includes fish, aquatic invertebrates, and crustaceans. It looks for prey while swimming on the water's surface. When food is located, it dives beneath the surface of the water after the prey. This species is migratory.
During the breeding season, the Hooded Merganser occurs in most of the eastern United States, with isolated populations in the central and northwestern portions of the United States. Wintering birds occur on coasts of California, and along the coasts of eastern and southern United States and northern Mexico. In Georgia during the breeding season, this species is rare in the Piedmont area and does not occur in the Coastal Plain. During the winter it is fairly common along the Coastal Plain.
The Hooded Merganser is listed as Endangered in Kentucky. It is not very common throughout the remainder of the Southeast, but it s not listed as requiring any special conservation protection in any other state.
The two species most similar to the Hooded Merganser are the Common Merganser and the Red-breasted Merganser. The males of both of these species lack the Hooded Merganser's black head with large white patch. The Common Merganser has a red bill; the males have a green head, and the females have a rusty red head. The male Red-breasted Merganser has a green head and a white collar, while the female has a pale red-brown head rather than being all brown like the female Hooded Merganser is.