Nests in cavities. During the nonbreeding season the male looks similar to the female, except that his eyes are yellow and the female's eyes are brown. It is the only extant species in the genus Lophodytes. The adult female has a greyish-brown body, with a narrow white patch over the lower breast and belly. The black head has a large white patch that varies in size when the crest is raised or lowered, but is always prominent. The hooded merganser is a sexually dimorphic species. Young: within 24 hours after hatching, young leave nest; female calls to them from below, young climb to cavity entrance and jump to ground. Females often lay eggs in each others' nests, also in nests of Wood Ducks and others. They compete with Wood Ducks for nest boxes put out by humans, and females of both species may lay eggs in the same nest, with one or the other incubating the eggs. One is in the eastern United States from the southern Canada–US border along the Atlantic Coast to the Gulf Coast in the region of the Mississippi delta. The female will lay a clutch of 7-15 eggs but only begins incubation when the last egg has been laid, thereby permitting synchronous hatching. They prefer fresh water but do occur on brackish water bodies as well.[8]. A smaller year-round range extends from Washington state and southern British Columbia to northern Idaho. Hooded Merganser (, Heusmann, H. W. and T. Early (1988). One priority consideration when managing wooded habitat for cavity nesting ducks, is to maintain a sufficient population of mature trees in which suitable nesting cavities would be plentiful. [12][14][15], Rabbitss, Brian (2009). [4], First-winter birds differ from adult females in appearance in that they have a grey-brown neck and upper parts; the upper parts of adult females are much darker — nearly black. His lower flanks are a rich reddish-brown or chestnut in colour, and the breast and undersides are more or less white, extending into white stripes across the crop and breast. Females and immatures are gray and brown, with warm tawny-cinnamon tones on the head. [12] In addition these ducks do make use of artificial nest boxes when available. Most studies report that its diet varies according to circumstances, usually being dominated by fishes (44-81%). Breeding occurs anytime between the end of February and the end of June, depending on the region. The hooded merganser was one of the many bird species originally described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae, where it was given the binomial name Mergus cucullatus.[3]. In breeding plumage the dorsal areas and the head, neck and breast of the mature male are mainly black with white markings; there are large white patches on either side of the crest, and they are particularly conspicuous when he raises his crest during courtship. The hooded merganser has a sawbill but is not classified as a typical merganser. Because these waterfowl are cavity nesters, they require mature trees in which suitable nesting sites are likely to be found. The adult female has a greyish-brown body, with a narrow white patch over the lower breast and belly. The hooded merganser is a diving predator that largely hunts by sight while under water. They prefer cavities 4–15 feet off the ground. Females and immature males are brown overall with a puffy crest and a thin orange stripe along the bottom of the bill. The hooded merganser (Lophodytes cucullatus) is a species of merganser. Hooded Mergansers are cavity nesters, frequently choosing trees that are close to ponds, marshes, swamps or streams. She can also raise her crest They nest in trees in woodland