The redhead (Aythya americana) is a medium-sized diving duck. The scientific name is derived from Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin americana, of America. The redhead is long with an wingspan; the weight ranges from , with males weighing an average of and females an average of . This waterfowl is easily distinguished from most other ducks by the male's copper colored head and pale blue bill during the breeding season; from its close relative canvasback it is distinguished by the more rounded head, shorter bill, and (in the males) yellow, not red, eye. The Eurasian common pochard is even more similar, but very rarely overlaps in range; it also differs in having a red eye, and a more acute, less rounded head shape.

Taxonomy and phylogeny

Taxonomy

The redhead is in the family Anatidae (ducks, swans, geese) and genus Aythya (diving ducks). There are currently no accepted subspecies of the redhead. The specimens were collected in North America and came to the Liverpool national collection via Thomas Campbell Eyton's collection and the 13th Earl of Derby's collection which was bequeathed to the city of Liverpool.

Males

During breeding season, adult males have a copper head and neck, with a black breast. The back and sides are gray, the belly is white and the rump and tail are black. Male bills are pale blue with a black tip and a thin ring separating the two colors. Non-breeding males lose the copper color and instead have brown heads. The eyes are yellow, one of the most obvious distinctions from canvasback and common pochard, which have red eyes. When wintering, redheads switch to large areas of water near the coast that are protected from wave action, but can also be found in reservoirs, lakes, playa wetlands, freshwater river deltas, coastal marshes, estuaries and bays. The population size has increased in the past few decades to well over 1.4 million birds.

Fall

Western birds migrate through Great Basin to the Pacific Coast. In British Columbia, fall migration begins in September and continues through October. The Great Salt Lake region is of particular importance to migrants in western United States. Central North American redheads will begin migrating earlier, around August/September and go through the Great Plains to the Texas coast. Eastern populations will migrate through the Great Lakes region to the Atlantic Coast or Florida from October to November. Most redheads winter along the Gulf of Mexico (offshore Louisiana, Florida and Mexico). However, eastern populations will winter in South Carolina. Redheads do not defend their territory or home range; they are instead social while in their breeding ground. This is thought to facilitate brood parasitism on other pochards, which is particularly prevalent on the part of younger, less experienced redhead females. The eggs measure 5.1–6.7 cm (2.0–2.6 in) in length and 3.9–4.7 cm (1.5–1.9 in) in width. Brood sizes range from 5 to 7 young, with the mother abandoning the chicks at 8 weeks old, 2–4 weeks before they are capable of flight.

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File:Redhead duck 1.jpg|Breeding male

File:Redhead in Central Park (15459).jpg|Breeding male

File:Redhead (female), Olivera Park, Texas (26965011152).jpg|Adult Female

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References

  • Redhead Species Account—Cornell Lab of Ornithology
  • Redhead—Aythya americana —USGS Patuxent Bird Identification InfoCenter
  • Sound, Sound metadata Macaulay Library, Cornell Lab of Ornithology