Redheads have adapted parasitic egg-laying strategies, where they lay their eggs in another duck's nest.
(See Reproduction section.)
Their eggs are also part of the food web for predators.
(Bellrose, 1976)
Species Used as Host:
Some Redheads build their nests over the water so that terrestrial animals, like skunks, will not destroy them. Unfortunately, water poses no problem for raccoons. Terrestrial and bird predators eat the duck's eggs. Redheads also attempt to hide their nests, and this greatly reduces the risk of predation.
The female of the species has muted colors so that she will be less noticible to predators when she is incubating her clutch. The ducklings are camouflaged as well. This characteristic allows the ducks to conceal themselves from sport hunters, too.
(Bellrose, 1976)
Known Predators:
Males of this species are characterized by a copper-colored head and orange-yellow eyes. The back and flanks are greyish in color, the chest and tail is blackish, the breast is white, and the belly is a whitish color marked with dusty undertones. The wings are grey with slight flecks of white. The feet are bluish grey in color. When the male duck molts in June, the blackish color become more brown, and the reddish head is not as vibrant. By November, darker winter feathers have grown in.
Females do not have colors as vibrant as male coloration. The head of a female is a yellowish brown that is a bit darker on the crown, and she has a slight pale ring around her brown eyes. Her body and tail is mostly dark greyish brown and her belly is whitish fading into greyish brown. Her wings are also a brownish grey color. Her feet are a bluish color, although a little duller than that of the male.
Both the male and the female of this species have a pale blue bill with a white ring around the black tip. It is about .5 inches long. Again, the female's coloring is not as dark.
The juvenile duck's first plumage resemble a mottled version of the female. As the duckling matures, the male becomes darker than the female and they begin to have the coloring of the adults.
Mass - Males: 2.1 to 3.2 pounds, average 2.44 pounds
Females: 1.5 to 2.9 pounds, average 2.14 pounds
Length - Males: 18.1 to 21.7 inches, average 20.0 inches
Females: 18.0 to 20.5 inches, average 19.0 inches
Wingspan - Males: average 9.16 inches
Females: average 8.79 inches
(Bellrose, 1976; Kortright, 1942; Phillips and Lincoln, 1930)
Range mass: 680 to 1450 g.
Range length: 457 to 550 mm.
Average wingspan: 228 mm.
Other Physical Features: endothermic ; bilateral symmetry
Disease greatly affects the longevity of the Redhead. Duck Virus Enteritis (DVE), caused by the herpes virus, can cause hemorrhaging and death within two weeks of exposure. If the duck survives, it may become a carrier of the disease. Redheads are moderately susceptible to this. Another disease that affects the ducks is avian botulism. The disease affects the peripheral nerves, and one characteristic is a drooping neck. Maggots feed on the birds that died of avian botulism, concentrating toxin inside themselves. When a Redhead eats the maggot, the toxin is ingested and the cycle starts all over again. Lead posioning is also a major cause of death in waterfowl. The duck eats the lead pellets that have been discarded from shotgun shells. The duck will become weaker over time until it starves to death. Redheads are very susceptible to this because they are bottom-feeders. Also, one of the greatest threats to the Redhead is hunting.
The oldest known wild Redhead lived 22 years 7 months after banding.
(Baldassarre and Bolen, 1994; USGS Bird Banding Laboratory, 2003)
Range lifespan
Status: wild: 22.5 (high) years.
Average lifespan
Status: wild: 271 months.
Aythya americana habitat includes shallow freshwater lakes, ponds, and marshes. The body of water needs to be at least 28 inches deep so that the ducks can dive. The Prairie Pothole region provides a perfect area for breeding due to the fact that the potholes fill up with water from melting snow and rain to provide temporary, seasonal, deposits of freshwater. Marshes also provide an area rich with aquatic plants and vegetation cover to act as protection. The ducks may be found on brackish and coastal bays and lakes.
(Baldassarre and Bolden, 1994; Johnsgard, 1992)
Habitat Regions: temperate ; terrestrial ; freshwater
Aquatic Biomes: lakes and ponds
Wetlands: marsh
The Aythya americana breeding range extends from southern Canada to the northern United States (Washington to Maine). Many breed in the Prairie Pothole region of the northern Great Plains of North America. There are also some breeding populations in central Alaska. In September, these ducks migrate to winter in northern and central Mexico, and from California to the Gulf and Atlantic Coast. A large portion of redheads winter in Florida and Mexico.
Biogeographic Regions: nearctic (Native )
Redhead diet is mainly composed of vegetable matter. It dives to the bottom of the body of water to feed on aquatic plants and mollusks and dabbles on the surface of shallow marshes to locate insects. Prior to the egg-laying season the females up their animal matter intake to increase their protein levels. At this time about 77% of their diet is animal related. About half of the duckling's diet is made up of animal matter to supply the nutrients needed to grow.
Foods commonly eaten include: shoalgrass, pondweeds, muskgrass, sedges, grasses, wild celery, duckweeds, water lilies, grasshoppers, caddisflies, midges, water fleas, scuds, water boatmen and snails.
(Kortright, 1942; Baldassarre and Bolen, 1994)
Animal Foods: insects; mollusks
Plant Foods: leaves; algae
Primary Diet: omnivore
The Redhead can be a tasty dinner for humans. Because of the Redhead's diet, it does not have the fishy flavor that other waterfowl have.
These ducks are also common in waterfowl collections because as breeders, they are fairly reliable.
(Kortright, 1942; Todd, 1979)
Positive Impacts: food
None known.
After an incubation period of 24-28 days, the eggs of the Redhead hatch. The ducklings remain in the nest for 3-18 hours after hatching so that their down can dry. At 56 days, the juvenile can be seen flapping accross the water, and at 70 to 84 days the ducks are learning to fly. Some ducks can sexually reproduce at a year, but more time is usually needed.
(Bellrose, 1976)
In the 1970's the Redhead population took a major blow. The vegetation of the Chesapeake Bay area had been declining for years. The combination of agriculture and urban expansion affecting the turbidity of the water, excessive amounts of nutrients, pollution from agriculture, and contamination of toxins added to the disruption of the birds' habitat. As if all of these factors were not enough, Hurricane Agnes greatly affected run-off, thus increasing sediments and decreasing salinity. All these events had a major impact on the vegetation, the primary food source of the Redheads. They were forced to feed on other forms of vegetable life. The states of Maryland and Virginia have created preservation programs in an attempt to reverse the degredation. These programs aim to protect the wildlife and increase research in the area.
In 1908, President Theodore Roosevelt established the Malheur National Wildlife Refuge to protect breeding and migrating waterfowl. It is one of the largest freshwater marshes in the United States. A major breeding population of Redheads resides there.
Because of an overhunting problem, laws were enacted to try to limit these types of deaths.
(Baldassarre and Bolden, 1994)
US Migratory Bird Act: protected
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Perception Channels: visual ; tactile ; acoustic ; chemical
Common names: redhead, pochard, raft duck, red-headed raft duck, American pochard, red-headed broadbill, fool duck, fiddler
(Bellrose, 1976; Phillips and Lincoln, 1930)
During courtship the females take the lead. The female will stand up tall and jerk her head up and down, and then hold it erect. The male she is after will also stand erect and twirl around, showing his backside to her. She may playfully nip at him, or while swimming, dash off and intersect him in his path.
If a female is focusing her attention on more than one male at a time, the males attempt to drive each other away.
Redheads tend to pair in late winter, but courtship behavior can be seen up into the month of April. This is the month where peak pair formation occurs. The males desert the females once incubation begins.
(Bellrose, 1976; Kortright, 1942)
Mating System: monogamous
Redheads tend to begin their breeding season in late April to early June. When a large group of breeding Redheads were studied, it was found that only half of the pairs were breeding. Apparently not all Redhead hens attempt to breed. These non-breeding hens are probably primarily yearlings.
Redheads begin to nest in the midsummer in marshes and potholes of the prairies. Nest sites may be located over water via the support of dense vegetation, on islands, or dry land. If the nest is on land, water must be nearby. Their first choice is to structure the nest using hardstem bulrush followed by cattails. The nest is deeply hollowed and lined with a thick layer of down.
Redheads exhibit interesting egg-laying strategies. Three behaviors are described: normal, semiparasitic, and parasitic. Normal behavior is when the hen lays and incubates her own eggs. Semiparasitic entails normal behavior and laying eggs in other nests. Parasitic is where the hen lays all of her eggs in another duck's nest. Often, the parasitic hen will lay her eggs in another duck's nest after incubation has occurred. This means that the parasitic female's eggs will probably not hatch because they are off schedule from the other eggs. The unhatched eggs are wasted. Sometimes the parasitic female will lay her eggs in the nest of another species.
A female lays, on average, one egg a day, but will skip a few days before the clutch is complete. On average, only 52% of nests have some eggs that have hatched.
(Bellrose, 1976; Kortright, 1942)
Breeding season: late April to early June
Range eggs per season: 9 to 11.
Range time to hatching: 24 to 28 days.
Range fledging age: 55 to 75 days.
Range age at sexual or reproductive maturity (female): 1 (low) years.
Average age at sexual or reproductive maturity (female): 1 years.
Range age at sexual or reproductive maturity (male): 1 (low) years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Average eggs per season: 13.
Right before the eggs hatch, the female emits a low kuk-kuk-kuk sound. This sound is extremely important because it imprints on the ducklings to follow her when they are hatched. Redheads are known for their early desertion of their young, and the mother leaves the juveniles when they are able to fly.
(Bellrose, 1976)
Parental Investment: precocial ; female parental care
Ironically, the Redhead is not the only duck in North America with a red head. In many parts of its range, this species occurs side by side with another redheaded duck, the Canvasback (Aythya valisineria), and a couple field marks must be noted in order to distinguish the two. The Redhead is slightly smaller (19-20 inches), has a shorter bill, and is darker on the back and flanks. Males have a red head and grey body, while females are mostly dark brown. The Redhead breeds primarily in the northern Great Plains, with smaller breeding populations in the southern Plains, the Rockies, and Alaska. Although some western areas see Redheads all year, most Redhead populations migrate south to the southern two-thirds of the United States and into Mexico in winter. Despite this vast winter range, much higher concentrations of wintering Redheads may be found along the coast than in the interior. Redheads breed in freshwater wetlands. In winter, this species primarily inhabits coastal areas with plentiful seagrasses. Redheads predominantly eat aquatic plants in summer; in winter, their diet includes seagrasses and mollusks. One of several species of “diving ducks” in North America, Redheads may be observed submerging themselves to feed on submerged plant matter. In winter, they may also be observed in large flocks on coastal bays and lagoons. This species is primarily active during the day.
Ironically, the Redhead is not the only duck in North America with a red head. In many parts of its range, this species occurs side by side with another redheaded duck, the Canvasback (Aythya valisineria), and a couple field marks must be noted in order to distinguish the two. The Redhead is slightly smaller (19-20 inches), has a shorter bill, and is darker on the back and flanks. Males have a red head and grey body, while females are mostly dark brown. The Redhead breeds primarily in the northern Great Plains, with smaller breeding populations in the southern Plains, the Rockies, and Alaska. Although some western areas see Redheads all year, most Redhead populations migrate south to the southern two-thirds of the United States and into Mexico in winter. Despite this vast winter range, much higher concentrations of wintering Redheads may be found along the coast than in the interior. Redheads breed in freshwater wetlands. In winter, this species primarily inhabits coastal areas with plentiful seagrasses. Redheads predominantly eat aquatic plants in summer; in winter, their diet includes seagrasses and mollusks. One of several species of “diving ducks” in North America, Redheads may be observed submerging themselves to feed on submerged plant matter. In winter, they may also be observed in large flocks on coastal bays and lagoons. This species is primarily active during the day.
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.[2] The redhead is 37 cm (15 in) long with an 84 cm (33 in) wingspan. Redhead weight ranges from 2.0 to 2.5 lbs (907-1134 g),[3] with males weighing an average of 2.4 lbs (1089 g) and females weighing an average of 2.1 lbs (953 g).[4] It belongs to the genus Aythya, together with 11 other described species. The redhead and the common pochard form a sister group which together is sister to the canvasback.[5]
The redhead goes by many names, including the red-headed duck and the red-headed pochard.[6] This waterfowl is easily distinguished from other ducks by the male's copper coloured head and bright blue bill during the breeding season.[7]
The redhead is in the family Anatidae (ducks, swans, geese) and genus Aythya (diving ducks). There are currently no described subspecies of the redhead.[6]
The two syntype specimens of Fuligula americana Eyton (Monogr. Anat., 1838, p.155) are held in the vertebrate zoology collections of National Museums Liverpool at World Museum, with accession numbers NML-VZ D829 (male immature) and NML-VZ D829a (female adult).[8] The specimens were collected in North America and came to the Liverpool national collection via Thomas Campbell Eyton’s collection[9] and the 13th Earl of Derby’s collection which was bequeathed to the city of Liverpool.[8]
The redhead and the common pochard form a sister group which itself is sister to the canvasback.[5] This group is then sister to the monophyletic group consisting of the white-eyes (hardhead, Madagascar pochard, and the sister species ferruginous duck and baer's pochard) and scaups (New Zealand scaup, ring-necked duck, tufted duck, greater scaup, lesser scaup).[5]
The redhead is a pochard, a diving duck specially adapted to foraging underwater. Their legs are placed farther back on the body, which makes walking on land difficult, the webbing on their feet is larger than dabbling ducks and their bills are broader, to facilitate underwater foraging. In addition, pochards have a lobed hind toe.[6] No pochard has a metallic coloured speculum, something that is characteristic of other ducks.[10]
During breeding season, adult males have a copper head and neck, with a black breast. The back and sides are grey, the belly is white and the rump and tail are a light black. Male bills are pale blue with a black tip and a thin ring separating the two colours. Non breeding males lose the copper colour and instead have brown heads.[7]
Adult females, however, have a yellow to brown head and neck. The breast is brown, the belly is white and the rest of the body is a grey to brown. The female bills are slate with a dark tip that is separated by a blue ring. Females remain the same colour year round.[7]
During breeding season, redheads are found across a wide range of North America, from as far north as Northern Canada to the Caribbean. Their preferred areas include the intermontane regions of British Columbia, Alberta, Saskatchewan, Manitoba, and the Dakotas with some small localities in Ontario, Quebec and southern United States. These pochards then migrate south to winter in warmer climates. These areas include southern United States where breeding does not occur and extends to Mexico, Guatemala, Cuba, and the Bahamas.[6][7] In either season, redheads use wetlands as their main habitat.[7]
Small, semi-permanent wetlands in non-forested country where the water is deep enough to provide dense emergent vegetation is considered ideal breeding habitat for redheads.[6][11] 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.[6][7][11]
Redheads do not have many predators and are most likely to die of disease or indirect human impact. These ducks are considered less desirable as table fare than their puddle duck cousins like the mallard; however, their beautiful plumage makes them a targeted species for waterfowl hunters looking to focus on diving ducks. Adults can be preyed upon by northern river otters, red-tailed hawks, great horned owls, bald eagles, golden eagles and to a greater extent, minks.[12] Most predation comes in the form of duckling predation and egg foraging. Northern pike and snapping turtles are known to eat ducklings whereas skunks, minks, crows and magpies will steal and eat redhead eggs.[6][12]
The North American Waterfowl Management Plan for redheads is 760,000 North American birds.[13] The population size has increased in the past few decades to well over 1.4 million birds.[7] Redheads make up 2% of North America's duck population and only 1% of its harvested ducks.[13] Populations may be stable because of restrictive bag limits for the species. In addition, the species uses semi-permanent and permanent wetlands to breed and these habitats are less likely to be affected by drought. For future management of the species, organizations are looking into wetland conservation.[13]
Redheads leave their winter range in late January and February with all birds migrating by mid-March. In western North America, migrants begin arriving in Oregon, British Columbia and Colorado in February. In central North America, migrants arrive as soon as temperatures open wetlands and lakes, which can range from late February (Nebraska) to early May (Alberta, Manitoba and Iowa). In the Great Lakes region and north-eastern North America, migrants will also arrive as soon as bodies of water open up.[14]
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.[14]
Redheads flock together on lakes and other bodies of water but will migrate in pairs, which are formed in December or January through elaborate courtship rituals.[6] Unpaired redheads will migrate together in a ‘courting party’ that can be up to 25 individuals strong and hopefully find a mate within the group.[6] The pair bonds are established yearly through a long courtship process. Males begin this process through neck-kinking and head throwing displays while emitting a cat-like call.[14] The male will continue by initiating a neck-stretching display while producing a cough like call, a display and vocalization in which the females reciprocates. If interested, the female will herself produce inciting calls towards the male while performing alternate lateral and chin lifting movements. The male then swims ahead of her and turns the back of his head towards the female.[6] Once courtship is finished, the two birds are paired for the year. Eventually, the male initiates copulation by alternating bill dipping and preening dorsally towards the female, an action in which the female might return to the male.[10]
Once copulation is completed, female redheads begin forming nests. They are built with thick and strong plant material in emergent vegetation, such as hard stem bulrush, cattails and sedges, over or near standing water.[6][12] Redheads do not defend their territory or home range and are actually very social while in their breeding ground. This is thought to occur because some younger, inexperienced redhead females parasitize other pochards.[6] Some redheads lay their eggs in other pochards’ nests, including the canvasback, ring-necked duck and greater and lesser scaups and this social parasitism by redheads reduces the hatching success of other pochards’ eggs, especially those of the canvasback.[6] In contrast, because of the parasitic relationship between the redhead and other pochards, redhead hybrids with the ring-necked duck, canvasback and the greater and lesser scaups have been found.[10] Canvasback x redhead hybrids can be fertile.[15] Brood sizes range from 5-7 young, with the mother abandoning the chicks at 8 weeks old, before they are capable of flying.[13] They remain flightless for another 2–4 weeks.[13]
There is little information on redhead vocalizations outside of breeding calls. Males will emit calls when courting the female.[10] When the neck is fully extended in the neck-stretching display, males will emit a distinct wheee-oww, which sounds catlike.[6][10] Males may also produce a soft coughing call, although this call is less frequent.[6] Females will emit a soft errrr note when she is inciting a male.[6]
All pochards have similar diets that include both plant and animal materials. Redheads undergo a niche switch when breeding and when wintering. During the breeding season, redheads will eat as much animal matter as possible, including gastropods, mollusks and insect larvae.[6][7] They will eat the occasional grass and other emergent vegetation.[7] However, once they fly south, redheads will change their diet to include mostly plant material, including pondweeds, wild rice, wild celery, wigeon grass, bulrushes, muskgrass and shoal grass.[6][7]
Gastropods known as food of Aythya americana include: Acteocina canaliculata, Acteon punctostriatus, Anachis avara, Anachis obesa, Caecum nitidum, Calliostoma sp., Cerithidea pliculosa, Cerithium lutosum, Crepidula convexa, Diastoma varium, Melanella sp., Mitrella lunata, Nassarius acutus, Nassarius vibex, Natica sp., Neritina virginea, Odostomia trifida, Olivella minuta, Olivella watermani, Polinices sp., Pyramidellidae, Pyrgocythara plicosa, Rissoina catesbyana, Sayella livida, Turbonilla sp., Turbonilla interrupta and Vitrinella sp.[16]
Breeding male
Breeding male
Female
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 37 cm (15 in) long with an 84 cm (33 in) wingspan. Redhead weight ranges from 2.0 to 2.5 lbs (907-1134 g), with males weighing an average of 2.4 lbs (1089 g) and females weighing an average of 2.1 lbs (953 g). It belongs to the genus Aythya, together with 11 other described species. The redhead and the common pochard form a sister group which together is sister to the canvasback.
The redhead goes by many names, including the red-headed duck and the red-headed pochard. This waterfowl is easily distinguished from other ducks by the male's copper coloured head and bright blue bill during the breeding season.
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