The Canada goose (Branta canadensis), or Canadian goose, is a large wild goose with a black head and neck, white cheeks, white under its chin, and a brown body. It is native to the arctic and temperate regions of North America, and it is occasionally found during migration across the Atlantic in northern Europe. It has been introduced to the United Kingdom, Ireland, Finland, Sweden, Denmark, New Zealand, Japan, Chile, Argentina, and the Falkland Islands. Like most geese, the Canada goose is primarily herbivorous and normally migratory; often found on or close to fresh water, the Canada goose is also common in brackish marshes, estuaries, and lagoons.
Extremely adept at living in human-altered areas, Canada geese have established breeding colonies in urban and cultivated habitats, which provide food and few natural predators. The success of this common park species has led to its often being considered a pest species because of its excrement, its depredation of crops, its noise, its aggressive territorial behavior toward both humans and other animals, and its habit of stalking and begging for food, the latter a result of humans disobeying artificial feeding policies toward wild animals.
The Canada goose was one of the many species described by Carl Linnaeus in his 18th-century work Systema Naturae. It belongs to the Branta genus of geese, which contains species with largely black plumage, distinguishing them from the grey species of the genus Anser.
Branta was a Latinised form of Old Norse Brandgás, "burnt (black) goose" and the specific epithet canadensis is a New Latin word meaning "from Canada". According to the Oxford English Dictionary, the first citation for the 'Canada goose' dates back to 1772. The Canada goose is also colloquially referred to as the "Canadian goose". This name may annoy some birders.
The cackling goose was originally considered to be the same species or several subspecies of the Canada goose, but in July 2004, the American Ornithologists' Union's Committee on Classification and Nomenclature split them into two species, making the cackling goose into a full species with the scientific name Branta hutchinsii. The British Ornithologists' Union followed suit in June 2005.
The AOU has divided the many subspecies between the two species. The subspecies of the Canada goose were listed as:
Atlantic Canada goose (B. c. canadensis) (Linnaeus, 1758)
Interior Canada goose (B. c. interior) (Todd, 1938)
Giant Canada goose (B. c. maxima) (Delacour, 1951)
Moffitt's Canada goose (B. c. moffitti) (Aldrich, 1946)
Vancouver Canada goose (B. c. fulva) (Delacour, 1951)
Dusky Canada goose (B. c. occidentalis) (Baird, 1858)
Lesser Canada goose (B. c. parvipes) (Cassin, 1852)
The distinctions between the two geese have led to confusion and debate among ornithologists. This has been aggravated by the overlap between the small types of Canada goose and larger types of cackling goose. The old "lesser Canada geese" were believed to be a partly hybrid population, with the birds named B. c. taverneri considered a mixture of B. c. minima, B. c. occidentalis, and B. c. parvipes. The holotype specimen of taverneri is a straightforward large pale cackling goose however, and hence the taxon is still valid today and was renamed "Taverner's cackling goose".
In addition, the barnacle goose (B. leucopsis) was determined to be a derivative of the cackling goose lineage, whereas the Hawaiian goose (B. sandvicensis) originated from ancestral Canada geese. Thus, the species' distinctness is well evidenced. Ornithologist Harold C. Hanson, who had rediscovered wild populations of the Giant Canada Goose, proposed splitting Canada and cackling goose into six species and 200 subspecies. The radical nature of this proposal has been controversial; Richard Banks of the AOU urges caution before any of Hanson's proposals are accepted. International Code of Zoological Nomenclature has suppressed Hanson's proposals, based on the criticisms of Banks and other ornithologists. (Wikipedia)
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