Bufflehead
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The bufflehead (Bucephala albeola) is a small sea duck of the genus Bucephala, the goldeneyes. It breeds in Alaska and Canada and migrates in winter to southern North America. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae as Anas albeola.
TaxonomyEdit
The bufflehead was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae under the binomial name Anas albeola.<ref>Template:Cite book</ref> Linnaeus based his account on the "little black and white duck" that had been described in 1747 by the English naturalist George Edwards in the second volume of his A Natural History of Uncommon Birds. Edwards examined a specimen from Newfoundland provided by the archivist George Holmes (archivist), the deputy Keeper of Records in the Tower of London.<ref>Template:Cite book</ref> Linnaeus specified the type locality as America, but this has been restricted to Newfoundland following Edwards.<ref>Template:Cite book</ref> The bufflehead is now placed with two goldeneye species in the genus Bucephala that was introduced in 1858 by the American naturalist Spencer Baird. The genus name is derived from Ancient Greek Template:Wikt-lang Template:Transliteration, Template:Gloss, from Template:Transliteration Template:Gloss, and Template:Transliteration, Template:Gloss, a reference to the oddly bulbous head shape of the species. The species name albeola is a diminutive of Latin {{#invoke:Lang|lang}} meaning Template:Gloss.<ref>Template:Cite book</ref>
The modern species is monotypic: no subspecies are recognised.<ref name=ioc>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The extinct subspecies Bucephala albeola fossilis from the Late Pleistocene of California was originally described as a distinct extinct species, but is now considered to belong within the Bufflehead.<ref>Template:Cite journal</ref>
DescriptionEdit
The bufflehead ranges from Template:Convert long and weighs Template:Convert, with the drakes larger than the females. Averaging Template:Convert and Template:Convert, it rivals the green-winged teal as the smallest American duck. The bufflehead has a wingspan of 21.6 in (55 cm).<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Adult males are striking black and white, with iridescent green and purple heads and a large white patch behind the eye. Females are grey-toned with a smaller white patch behind the eye and a light underside.<ref name="Lippson">Template:Cite book</ref>
Distribution and habitatEdit
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. They can also be observed wintering on the Great Lakes. 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. From 1966 – 2015, the bufflehead experienced a >1.5% yearly population increase throughout its breeding range.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
BehaviorEdit
Buffleheads have evolved their small size to fit the nesting cavity of their "metabiotic" host, a woodpecker, the northern flicker.<ref name=Gauthier>Gauthier, G. 1993. Bufflehead, Bucephala albeola. The Birds of North America. (67), 24 pages. Edited by A. Poole and F. Gill, The Academy of Natural Sciences of Philadelphia.</ref> 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 serves as a sentry, watching for predators as the others in the group dive in search of food.<ref name="Lippson"/> 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.<ref>Finley, J.K. 2007. The punctual Bufflehead, Bucephala albeola: autumn arrivals in Shoal Harbour Sanctuary, Vancouver Island, in relation to freeze-up. Canadian Field-Naturalist 121:370-374.</ref>
BreedingEdit
Buffleheads are monogamous,<ref name=Gauthier/> and the females may return to the same nest site, year after year. They nest in cavities in trees, primarily aspens or poplars, using mostly old flicker nests, close (usually < Template:Convert) 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 goldeneye killing 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 foxes (Vulpes and Urocyon sp.), weasels (Mustela and Neogale sp.) or mink (Neogale vison), and by goldeneyes over nest competition.
Average clutch size is nine (range six to 11), and eggs average Template:Convert.<ref name=Gauthier/> 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.<ref name=Erskine>Erskine, A. J. 1972. Buffleheads. Canadian Wildlife Service Monograph Series #4. Information Canada, Ottawa. 240 pages</ref> 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), and Cooper's hawk (Accipiter cooperii).
DietEdit
These diving birds forage underwater. They prefer water depths of Template:Convert.<ref name="Lippson"/> In freshwater habitats, they eat primarily insects, and in saltwater, they feed predominantly on crustaceans and mollusks. Aquatic plants and fish eggs can often become locally important food items, as well.
Relationship with humansEdit
Because of their striking plumage, highly active nature, and proximity to humans on waterfront properties, buffleheads are one of the most popular birds amongst bird watchers.<ref name=Erskine/> The bufflehead, also known as the spirit duck, was added to the coat of arms of the town of Sidney, British Columbia, in 1995.<ref name='city of sidney'>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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.<ref name=Gauthier/> 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.Template:Citation needed Although buffleheads do use man-made nest boxes, they still need the forest habitat to thrive.
ReferencesEdit
External linksEdit
- Bufflehead at Birds of North America Online
- BirdWeb.Org: Bufflehead
- Bufflehead at Boreal Birds
- Buffleheads in Winter Birdnote Archives, KPLU, 7 Dec 2009.
- Bufflehead Species Account – Cornell Lab of Ornithology
- Bufflehead – Bucephala albeola – USGS Patuxent Bird Identification InfoCenter
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- Template:VIREO
- Template:IUCN Map