Buffleheads, Bucephala albeola

Bufflehead/ Bucephala albeola/ Buffelkopeend / Büfflekopfente / Petit garrot

Recorded in aviculture/ aviary

The bufflehead is a small American sea duck of the genus Bucephala, the goldeneyes. This species was first described by Linnaeus in his Systema naturae in 1758 as Anas albeola.

Adult males are striking black and white, with iridescent green and purple heads with a large white patch behind the eye. Females are grey-toned with a smaller white patch behind the eye and a light underside.

The name bufflehead is a combination of buffalo and head, referring to the oddly bulbous head shape of the species. This is most noticeable when the male puffs out the feathers on his head, thus greatly increasing its apparent size.

They are migratory and most of them winter in protected coastal waters, or open inland waters, on the east and west coasts of North America and the southern United States. The Bufflehead is an extremely rare vagrant to western Europe. Their breeding habitat is wooded lakes and ponds in Alaska and Canada, almost entirely included in the boreal forest or taiga habitat.

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence less than 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 (over 30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (less than 10,000 mature individuals with a continuing decline estimated to be over 10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern (IUCN, 2012).

The global population is estimated to number over c.1,200,000 individuals (Wetlands International 2006), while the population in Japan has been estimated at fewer than c.50 wintering individuals (Brazil 2009).

Buffleheads have evolved their small size in order to fit the nesting cavity of their "metabiotic" host, a woodpecker, the northern flicker. Due to their small size, they are highly active, undertaking dives almost continuously while sustained by their high metabolism. They do not tend to collect in large flocks; groups are usually limited to small numbers. One duck will serve as a sentry, watching for predators as the others in the group dive in search of food. Buffleheads are amongst the last waterfowl to leave their breeding grounds and one of the world's most punctual migrants, arriving on their wintering grounds within a narrow margin of time.

Buffleheads are monogamous, and the females return to the same breeding site, year after year. They nest in cavities in trees, primarily aspens or poplars, using mostly old flicker nests, close (usually less than 25 m (82 ft)) to water. Nest competitors include mountain bluebird (Sialia currucoides), tree swallow (Tachycineta bicolor), and European starling. There was one recorded instance of a female Barrow's goldeneyekilling a bufflehead adult female and her brood. Smaller cavities are preferred because of less competition with the larger goldeneyes. Females may be killed on the nest by mammals, such as weasels (Mustela spp.) or mink (Mustela vison), and by goldeneyes over nest competition.

Average clutch size is 9 (range 6–11), and eggs average 50.5 by 36.3 mm (1.99 by 1.43 in). Incubation averages 30 days, and nest success is high (79% in one study) compared to ground-nesting species like the teal. A day after the last duckling hatches the brood leaps from the nest cavity. The young fledge at 50–55 days of age. Predators of adults include the peregrine falcon (Falco peregrinus), snowy owl (Bubo scandiacus), bald eagle (Haliaeetus leucocephalus), golden eagle (Aquila chrysaetos), red-tailed hawk (Buteo jamaicensis),great horned owl (Bubo virginianus), Eurasian eagle owl (Bubo bubo), and Cooper's hawk (Accipiter cooperii).

These diving birds forage underwater. They prefer water depths of 1.2–4.5 m (3.9–14.8 ft). In freshwater habitats they eat primarilyinsects, and in saltwater they feed predominantly on crustaceans and mollusks. Aquatic plants and fish eggs can often become locally important food items as well.

Buffleheads are hunted and are considered a gamebird. In contrast to many other seaducks that have declined in recent decades, bufflehead numbers have remained relatively constant. Habitat degradation is the major threat to this bird, since they depend on very limited coastal habitat on their wintering grounds, and very specific habitat in their boreal breeding grounds. Although buffleheads do use man-made nest boxes, they still need the forest habitat to thrive.

Видео Buffleheads, Bucephala albeola канала Jan Harteman