Brant | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Anseriformes |
Family: | Anatidae |
Genus: | Branta |
Species: | B. bernicla |
Binomial name | |
Branta bernicla | |
Global map of range [2] Winter non-breeding range Summer breeding range | |
Synonyms | |
Anas berniclaLinnaeus, 1758 |
The brant or brent goose (Branta bernicla) is a small goose of the genus Branta . There are three subspecies, all of which winter along temperate-zone sea-coasts and breed on the high-Arctic tundra.
The Brent oilfield was named after the species. [3]
The brant is a small goose with a short, stubby bill. It measures 55–66 cm (22–26 in) long, 106–121 cm (42–48 in) across the wings and weighs 0.88–2.2 kg (1.9–4.9 lb). [4] [5] [6] [7] The under-tail is pure white, and the tail black and very short (the shortest of any goose).
The species is divided into three subspecies: [8]
Some DNA evidence suggests that these forms are genetically distinct; while a split into three separate species has been proposed, it is not widely accepted, with other evidence upholding their maintenance as a single species.
The body of the dark-bellied formB. b. bernicla is fairly uniformly dark grey-brown all over, the flanks and belly not significantly paler than the back. The head and neck are black, with a small white patch on either side of the neck. With a population of about 250000, it breeds on the Arctic coasts of central and western Siberia and winters in western Europe, with over half the population in southern England, the rest between northern Germany and north-western France.
The pale-bellied brantB. b. hrota appears blackish-brown and light grey in colour. The body is different shades of grey-brown all over, the flanks and belly are significantly paler than the back and present a marked contrast. The head and neck are black, with a small white patch on either side of the neck. The total population is about 250,000, with the main population breeding in northeastern Canada and wintering along the Atlantic coast of the U.S. from Maine to Georgia, [4] and two smaller populations, one breeding in Franz Josef Land, Svalbard, and northeastern Greenland and wintering in Denmark, northeast England, and Scotland, and the other breeding in the far-northeastern Canadian islands and wintering in Ireland, southwest England, and in a small but significant area, le Havre de Regnéville, centered on the Sienne Estuary in Manche (Northern France). [9] In Ireland it is recorded in winter from a number of areas including Lough Foyle, Strangford Lough, Tralee Bay and Castlemaine Harbour. [10] [11] [12]
The black brantB. b. nigricans appears blackish-brown and white in colour. This form is a very contrastingly black and white bird, with a uniformly dark sooty-brown back, similarly coloured underparts (with the dark colour extending furthest back of the three forms) and a prominent white flank patch; it also has larger white neck patches, forming a near-complete collar. The population of about 125,000 breeds in northwestern Canada, Alaska and eastern Siberia, and winters mostly on the west coast of North America from southern Alaska to California, but also some in east Asia, mainly Japan, also Korea and China. The population has been as high as 200,000 in 1981, and as low as 100,000 in 1987. [13]
The Asian populations of the black brant populations had previously been regarded as a separate subspecies B. b. orientalis based on purported paler upperparts coloration; however, it is generally now believed that this is not correct, and they are assigned to B. b. nigricans.
A fourth form (known variously as gray brant, intermediate brant, or grey-bellied brent goose) has been proposed, although no formal subspecies description has been made as yet, for a population of birds breeding in central Arctic Canada (mainly Melville Island), and wintering on Puget Sound on the American west coast around the U.S./Canada border. These birds are intermediate in appearance between black brant and pale-bellied brant, having brown upperparts and grey underparts which give less of a contrast with the white flank patch. It has also been proposed that, rather than being a separate subspecies, it is actually a result of interbreeding between these two forms, given that this population exhibits mixed characters.
Individual birds when wintering generally remain in loose family-groups, together with others of the same sub-species, but there is overlap in some areas (for example Western Europe, see above); and this is also true in the breeding colonies. Outside the breeding season, individuals with characteristics of any subspecies may occasionally turn up with regular migrants, and there has been debate as to whether this is related to migration routing accidents, or to breeding range overlap, or even interbreeding.
The brant goose was strictly coastal bird in winter, rarely leaving tidal estuaries, where it feeds on eelgrass ( Zostera marina ) [8] and the seaweed, sea lettuce (Ulva). [4] [14] On the east coast of North America, the inclusion of sea lettuce is a recent change to their diet, brought about by a blight on eelgrass in 1931. This resulted in the near-extirpation of the brant. The few that survived changed their diet to include sea lettuce until the eelgrass eventually began to return. Brants have maintained this diet ever since as a survival strategy. [15] A similar collapse in eelgrass in Ireland in the 1930s also negatively impacted the population. [16] In recent decades, it has started using agricultural land a short distance inland, feeding extensively on grass and winter-sown cereals. It has been suggested that they learnt this behaviour by following other species of geese. Food resource pressure may also be important in forcing this change, as the world population increased over 10-fold to 400,000-500,000 by the mid-1980s, possibly reaching the carrying capacity of the estuaries. In the breeding season, it uses low-lying wet coastal tundra for both breeding and feeding. The nest is bowl-shaped, lined with grass and down, in an elevated location, often near a small pond.
The brant goose is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds applies.
Branta is a Latinised form of Old Norse brandgás, "burnt (black) goose", and bernicla is the medieval Latin name for the barnacle.
The brant and the similar barnacle goose were previously considered one species, formerly believed to be the same creature as the crustacean. [17] That myth can be dated back to at least the 12th century. Gerald of Wales claimed to have seen these birds hanging down from pieces of timber, William Turner accepted the theory, and John Gerard claimed to have seen the birds emerging from their shells. This myth arose because in the 1100s the migration of birds was unknown, but it was known that none of these birds was ever seen nesting, nor were eggs found, nor were goslings seen. [18]
The legend persisted until the end of the 18th century. In County Kerry, until relatively recently, Catholics could eat this bird on a Friday because it counted as fish. [19]
The nene, also known as the nēnē or the Hawaiian goose, is a species of bird endemic to the Hawaiian Islands. The nene is exclusively found in the wild on the islands of Oahu, Maui, Kauaʻi, Molokai, and Hawaiʻi. In 1957, it was designated as the official state bird of the state of Hawaiʻi.
The greylag goose or graylag goose is a species of large goose in the waterfowl family Anatidae and the type species of the genus Anser. It has mottled and barred grey and white plumage and an orange beak and pink legs. A large bird, it measures between 74 and 91 centimetres in length, with an average weight of 3.3 kilograms. Its distribution is widespread, with birds from the north of its range in Europe and Asia often migrating southwards to spend the winter in warmer places, although many population are resident, even in the north. It is the ancestor of most breeds of domestic goose, having been domesticated at least as early as 1360 BCE. The genus name is from anser, the Latin for "goose".
The greater white-fronted goose is a species of goose that is closely related to the smaller lesser white-fronted goose. The greater white-fronted goose is migratory, breeding in northern Canada, Alaska, Greenland and Russia, and winters farther south in North America, Europe and Asia. It is named for the patch of white feathers bordering the base of its bill: albifrons comes from the Latin albus "white" and frons "forehead". In the United Kingdom and Ireland, it has been known as the white-fronted goose; in North America it is known as the greater white-fronted goose, and this name is also increasingly adopted internationally. Even more distinctive are the salt-and-pepper markings on the breast of adult birds, which is why the goose is colloquially called the "specklebelly" in North America.
The pink-footed goose is a goose which breeds in eastern Greenland, Iceland, Svalbard, and recently Novaya Zemlya. It is migratory, wintering in northwest Europe, especially Ireland, Great Britain, the Netherlands, and western Denmark. The name is often abbreviated in colloquial usage to "pinkfoot". Anser is the Latin for "goose", and brachyrhynchus comes from the ancient Greek brachus "short" and rhunchos "bill".
The snow goose is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed in the genus Chen, but is now typically included in the "gray goose" genus Anser.
The barnacle goose is a species of goose that belongs to the genus Branta of black geese, which contains species with largely black plumage, distinguishing them from the grey Anser species. Despite its superficial similarity to the brant goose, genetic analysis has shown it is an eastern derivative of the cackling goose lineage.
The red-breasted goose is a brightly marked species of goose in the genus Branta from Eurasia. It is currently classified as vulnerable by the IUCN.
The Canada goose, sometimes called 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 France, 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.
The swan goose is a large goose with a natural breeding range in inland Mongolia, Northeast China, and the Russian Far East. It is migratory and winters mainly in central and eastern China. Vagrant birds are encountered in Japan and Korea, and more rarely in Kazakhstan, Laos, coastal Siberia, Taiwan, Thailand and Uzbekistan.
The black geese of the genus Branta are waterfowl belonging to the true geese and swans subfamily Anserinae. They occur in the northern coastal regions of the Palearctic and all over North America, migrating to more southernly coasts in winter, and as resident birds in the Hawaiian Islands. Alone in the Southern Hemisphere, a self-sustaining feral population derived from introduced Canada geese is also found in New Zealand.
The spur-winged goose is a large, Sub-Saharan African waterbird in the family Anatidae, which includes geese and shelducks. However, over millennia, P. gambensis developed unique environmental adaptations, which resulted in the evolution of several anatomical features that are not shared with other anatids; thus, the species has been classified one step further into its own subfamily, the Plectropterinae.
The kelp goose is a species of waterfowl in tribe Tadornini of subfamily Anserinae. It is found in Argentina, Chile, and the Falkland Islands.
The cackling goose is a species of goose found in North America and East Asia.
Anser is a waterfowl genus that includes the grey geese and the white geese. It belongs to the true goose and swan subfamily of Anserinae under the family of Anatidae. The genus has a Holarctic distribution, with at least one species breeding in any open, wet habitats in the subarctic and cool temperate regions of the Northern Hemisphere in summer. Some also breed farther south, reaching into warm temperate regions. They mostly migrate south in winter, typically to regions in the temperate zone between the January 0 °C (32 °F) and 5 °C (41 °F) isotherms.
A clutch of eggs is the group of eggs produced by birds, amphibians, or reptiles, often at a single time, particularly those laid in a nest.
The African pygmy goose is a perching duck from sub-Saharan Africa. It is the smallest of Africa's waterfowl, and one of the smallest in the world.
The Aleutian cackling goose is a small subspecies of the cackling goose averaging 1.7 to 2.1 kg in weight. It was one of 122 species of animals, birds, and fishes first documented for science by the Lewis and Clark Expedition.
The dusky Canada goose is a subspecies of the Canada goose. They are the darkest variant, similar to the Pacific cackling goose. Tagged dusky geese have red bands with white letters on them attached to their neck. They represent one of the smallest populations of Canada goose in the Pacific Northwest. Due to the species minimal population and exclusive breeding grounds, the dusky Canada goose is a species of interest to the Pacific Flyway Council and the U.S. Forest Service. The Cordova Ranger District, on the Chugach National Forest, has been working since 1984 to implement a monitoring and restoration program for the geese.
The giant Canada goose is the largest subspecies of Canada goose, on average weighing in at 5 kg. It is found in central North America. These geese were at one point considered extinct, but were later rediscovered. The giant Canada goose was once kept and bred in captivity for use as hunting decoys and for food.
The Moffitt's Canada goose, also known as the Western Canada goose or Great Basin Canada Goose is a subspecies of the Canada goose. Native to the western interior of North America surrounding the Rocky Mountains, its range has expanded due to introductions to various regions of western North America.