Redhead (duck)
Encyclopedia
The Redhead is a medium-sized diving duck
Diving duck
The diving ducks, commonly called pochards or scaups, are a category of duck which feed by diving beneath the surface of the water. They are part of the diverse and very large Anatidae family that includes ducks, geese, and swans....

, 37 cm long with an 84 cm wingspan.

The adult male has a blue bill, a red head and neck, a black breast, yellow eyes and a grey back. The adult female has a brown head and body and a darker bluish bill with a black tip.

The breeding habitat is marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

es and prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

 potholes in western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Loss of nesting habitat has led to sharply declining populations. Females regularly lay eggs in the nests of other Redheads or other duck
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...

s, especially Canvasback
Canvasback
The Canvasback is the largest of the North American diving ducks, that ranges from between long and weighs approximately , with a wingspan of . The canvasback has a distinctive wedge-shaped head and long graceful neck. The adult male has a black bill, a chestnut red head and neck, a black...

s. Redheads usually take new mates each year, starting to pair in late winter.

Following the breeding season, males go through a molt which leaves them flightless for almost a month. Before this happens, they leave their mates and move to large bodies of water, usually flying further north.

They overwinter in the southern
Southern United States
The Southern United States—commonly referred to as the American South, Dixie, or simply the South—constitutes a large distinctive area in the southeastern and south-central United States...

 and north-eastern United States
Northeastern United States
The Northeastern United States is a region of the United States as defined by the United States Census Bureau.-Composition:The region comprises nine states: the New England states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont; and the Mid-Atlantic states of New...

, the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

 region, northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 and the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

.

This strong migrant
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...

 is a very rare vagrant to western Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

.

Feeding habits

These birds feed mainly by diving or dabbling. They mainly eat aquatic plants Halodule wrightii (74 %) with some molluscs (21 %). Gastropods include 18% of food and bivalves include 3 % of its food.

Gastropods known as food of Aythya americana include: Acteocina canaliculata, Acteon punctostriatus, Anachis avara, Anachis obesa, Caecum nitidum, Calliostoma
Calliostoma
Calliostoma is a genus of small to medium-sized sea snails with gills and an operculum, marine gastropod molluscs within the family Calliostomatidae, the calliostoma top snails . Previously this genus was placed within the family Trochidae...

sp., Cerithidea pliculosa, Cerithium lutosum
Cerithium lutosum
Cerithium lutosum is a species of sea snail, a marine gastropod mollusk in the family Cerithiidae....

, Crepidula convexa
Crepidula convexa
Crepidula convexa is a species of sea snail, a marine gastropod mollusk in the family Calyptraeidae, the slipper snails or slipper limpets, cup-and-saucer snails, and Chinese hat snails.-Distribution:...

, Diastoma varium, Melanella
Melanella
Melanella is a genus of very small ectparasitic sea snails, marine gastropod mollusks or micromollusks in the family Eulimidae. -Species:...

sp., Mitrella lunata, Nassarius acutus
Nassarius acutus
Nassarius acutus, common name the sharp nassa, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks....

, Nassarius vibex
Nassarius vibex
Nassarius vibex, common name the bruised nassa, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.-Distribution:...

, Natica
Natica
Natica is a genus of small to medium-sized predatory sea snails, marine gastropods in the family Naticidae, the moon snails. The genus is known from the Cretaceous to the Recent periods.- Species :...

sp., Neritina virginea
Neritina virginea
Neritina virginea is a species of sea snail, a marine gastropod mollusk in the family Neritidae.-Distribution:This species occurs in the brackish waters on the West Indian island of Dominica....

, Odostomia trifida, Olivella minuta
Olivella minuta
Olivella minuta is a species of small sea snail, marine gastropod mollusk in the family Olivellidae, the dwarf olives....

, Olivella watermani
Olivella watermani
Olivella watermani is a species of small sea snail, marine gastropod mollusk in the family Olivellidae, the dwarf olives....

, Polinices
Polinices
Polinices is a genus of sea snails, marine gastropod molluscs in the family Naticidae known as moon shells. Glossaulax Pilsbry, 1929 is a synonym or a subgenus of Polinices.-Species:Species within the genus Polinices include:...

sp., Pyramidellidae
Pyramidellidae
Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

, Pyrgocythara plicosa
Pyrgocythara plicosa
Pyrgocythara plicosa, common name the plicate mangelia, is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.-Distribution:...

, Rissoina catesbyana, Sayella livida, Turbonilla
Turbonilla
Turbonilla is a genus of sea snails, marine gastropod mollusks in the family Pyramidellidae, the pyrams and their allies.-Species:Species within the genus Turbonilla include:* Turbonilla abrardi...

sp., Turbonilla interrupta and Vitrinella sp.

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