[order] ANSERIFORMES | [family] Anatidae | [latin] Aythya americana | [authority] Eyton, 1838 | [UK] Redhead | [FR] Fuligule a tete rouge | [DE] Rotkopf-Ente | [ES] Porron Americano | [NL] Amerikaanse Tafeleend
Subspecies
| Genus | Species | subspecies | Region | Range |
| Aythya | americana | NA | widespread |
Genus
Aythya is a genus of diving ducks. It has twelve described species. Aythya shihuibas was described from the Late Miocene of China. An undescribed prehistoric species is known only from Early Pleistocene fossil remains found at Dursunlu, Turkey; it might however be referrable to a paleosubspecies of an extant species considering its age. The Miocene “Aythya” arvernensis is now placed in Mionetta, while “Aythya” chauvirae seems to contain the remains of 2 species, at least one of which does not seem to be a diving duck.
Physical charateristics
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.
Listen to the sound of Redhead
[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Redhead.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 83 | cm | wingspan max.: | 85 | cm |
| size min.: | 37 | cm | size max.: | 39 | cm |
| incubation min.: | 23 | days | incubation max.: | 29 | days |
| fledging min.: | 0 | days | fledging max.: | 29 | days |
| broods: | 1 | eggs min.: | 4 | ||
| eggs max.: | 9 |
Range
North America : widespread
Habitat
Redheads nest on marshy freshwater lakes, ponds, slow moving rivers and other wetlands in prairie zones. During migration they gather on large lakes and they spend the winter on sheltered saltwater bays and estuaries and some inland lakes.
Reproduction
The breeding habitat is marshes and prairie potholes in western North America. Loss of nesting habitat has led to sharply declining populations. Females regularly lay eggs in the nests of other Redheads or other ducks, especially Canvasbacks. Redheads usually take new mates each year, starting to pair in late winter.
Feeding habits
These birds feed mainly by diving or dabbling. They mainly eat aquatic plants with some molluscs, aquatic insects and small fish.
Video Redhead
httpv://www.youtube.com/watch?v=bCGW7XQnBa4
copyright: youtube
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
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.
Redheads usually gather in small flocks, often mixed with other diving duck species. But in the winter they congregate in very large flocks, made up of tens of thousands of birds. Although they are considered divers, they often feed by dabbling. A notable behavior of the Redhead is their tendency to parasitize, or lay eggs in other duck’s nests. Many ducks will lay eggs in each others nests, but the Redhead takes this practice to another level. Female Redheads regularly parasitize each other, and at least ten other species of duck, and some non-duck species as well. Most females parasitize in addition to raising their own brood, but some females may be entirely parasitic, not raising their own brood at all. Sometimes, dump nests occur that are untended and never incubated, but may have up to 87 eggs in them.
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.
Redheads usually gather in small flocks, often mixed with other diving duck species. But in the winter they congregate in very large flocks, made up of tens of thousands of birds. Although they are considered divers, they often feed by dabbling. A notable behavior of the Redhead is their tendency to parasitize, or lay eggs in other duck’s nests. Many ducks will lay eggs in each others nests, but the Redhead takes this practice to another level. Female Redheads regularly parasitize each other, and at least ten other species of duck, and some non-duck species as well. Most females parasitize in addition to raising their own brood, but some females may be entirely parasitic, not raising their own brood at all. Sometimes, dump nests occur that are untended and never incubated, but may have up to 87 eggs in them.
Migration
They overwinter in the southern and north-eastern United States, the Great Lakes region, northern Mexico and the Caribbean.
This strong migrant is a very rare vagrant to western Europe.
Distribution map
Literature
Title Survey for Blood Parasites in Redheads (Aythya americana) Wintering at the Chandeleur Islands, Louisiana
Author(s): Thomas C. Michot
Abstract: We detected no infections with species of Plasmodi..[more]..
Source: Journal of Wildlife Diseases, 31(1), 1995, pp. 90-92
Title FOOD HABITS OF REDHEADS (AYTHYA AMERICANA) WINTERING IN SEAGRASS BEDS OF COASTAL LOUISIANA AND TEXAS, USA
Author(s): MICHOT, T. C et al
Abstract: Diets of wintering redheads (Aythya americana) hav..[more]..
Source: Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 239-250, 2008
Title SALT GLAND DEVELOPMENT IN MIGRATORY REDHEADS
(AYTHYA AMERICANA) IN SALINE ENVIRONMENTS ON THE
WINTER RANGE, GULF OF MEXICO, USA
(AYTHYA AMERICANA) IN SALINE ENVIRONMENTS ON THE
WINTER RANGE, GULF OF MEXICO, USA
Author(s): WOODIN, M. C
Abstract: Redheads (Aythya americana) migrate annually from ..[more]..
Source: Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 251-264, 2008
Title Wetland Salinity and Salt Gland Size in the Redhead Aythya americana
Author(s): STEPHEN E. CORNELIUS
Abstract: Numerous investigators have shown experimentally t..[more]..
Source: Auk, Vol. 99
Title Record of a Redhead, Aythya americana, laying eggs in a Northern Harrier, Circus cyaneus, nest
Author(s): Fleskes,J. P
Abstract: Alberta; Anatidae; Aythya americana; Circus; Circu..[more]..
Source: Canadian Field-Naturalist 106:263-264.