[order] ANSERIFORMES | [family] Anatidae | [latin] Branta bernicla | [authority] Linnaeus, 1758 | [UK] Brant Goose | [FR] Bernache cravant | [DE] Ringelgans | [ES] Barnacla de Cara Negra | [NL] Rotgans
Monotypic species
Genus
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 birds of one species is also found in New Zealand. one species has been described from subfossil remains found in the Hawaiian Islands, where it became extinct in prehistoric times. Another undescribed prehistoric species from the Big Island of Hawaii was extremely large and flightless; it is tentatively assigned to this genus due to being very peculiar. It is fairly certain that at least another species of this genus awaits discovery on the Big Island, judging from the facts that at least one species of Branta was found on every major Hawaiian island, and that remains of such birds have not been intentionally searched for on the Big IslandThe relationships of the enigmatic Geochen rhuax to this genus are unresolved. It was another prehistoric Big Island form and remains known only from some parts of a single bird’s skeleton, which were much damaged because the bird apparently died in a volcanic eruption, with the bones being found in an ash-filled depression under a lava flow. A presumed relation to the shelducks proposed by Lester Short in 1970 was generally considered highly unlikely due to that group’s biogeography, but more recently, bones of a shelduck-like bird have been found on Kauai. Whether this latter anatid was indeed a shelduck is presently undetermined. Several fossil species of Branta have been described. Since the true geese are hardly distinguishable by anatomical features, the allocation of these to this genus is somewhat uncertain. A number of supposed prehistoric grey geese have been described from North America, partially from the same sites as species assigned to Branta. Whether these are correctly assigned, meaning that the genus Anser was once much more widespread than today and that it coexisted with Branta in freshwater habitat which it today does only most rarely, is not clear. Especially in the case of B. dickeyi and B. howardae, doubts have been expressed about its correct generic assignment
The Brant is similar in appearance to the Canada Goose, but smaller and darker. The adult has a gray belly and breast, white rump, and black neck and head with a thin white necklace and no chin-strap.
Fast fliers with swept-back wings, Brant are usually found in a flock. They forage while wading, dabbling in shallow water, or while walking on mudflats or the shore. They display strong site-fidelity to both their wintering and nesting areas.
Listen to the sound of Brant Goose
[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Brant Goose.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: |
105 |
cm |
wingspan max.: |
117 |
cm |
| size min.: |
55 |
cm |
size max.: |
62 |
cm |
| incubation min.: |
24 |
days |
incubation max.: |
26 |
days |
| fledging min.: |
36 |
days |
fledging max.: |
26 |
days |
| broods: |
1 |
|
eggs min.: |
6 |
|
| |
|
|
eggs max.: |
10 |
|
North America, Eurasia : widespread
Brant are almost exclusively coastal in their range and are found in shallow bays and saltwater marshes. They nest in the wet, coastal tundra of the high Arctic. Their winter habitat is closely tied to the occurrence of sea grasses and marine algae.
Long-term pair bonds usually form on the wintering grounds. Nesting occurs in loose colonies, on small islands in tundra ponds. The breeding range of the Brant is typically within five miles of the coast. The nest is a shallow bowl of grass and other vegetation, lined with down. The female incubates 3 to 5 eggs for 22 to 24 days. The young leave the nest within a day of hatching, and both parents continue to tend them and lead them to sources of food. During the long days of the high-Arctic summer, the young feed at all hours, and grow quickly. They fledge at 40 to 50 days, but stay with the parents through the first migration.
Historically, Brant fed almost exclusively on eelgrass, which is still strongly preferred when available. Now they also forage on grasslands and have been able to diversify their diet in the absence of eelgrass, although their range is still closely tied to eelgrass. Brant also eat some aquatic invertebrates.
httpv://www.youtube.com/watch?v=yqVx4fh5b78
copyright: youtube
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <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 is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Branta bernicla is a rare breeder in the European Arctic, but winters mainly in coastal
areas of western Europe, which accounts for less than half of its global wintering
range. Its European wintering population is large (>240,000 individuals), and
increased between 1970-1990. Although a few populations increased or were broadly
stable during 1990-2000, key wintering populations (of the subspecies B. b. bernicla)
in the United Kingdom, France and the Netherlands declined, and the species
underwent a large decline (>30%) overall.
This goose is breeding on the arctic coasts of Eurasia and North America, mainly on small islets protected from polar foxes (Alopex lagopus). It winters along the temperate Atlantic and Pacific coasts. The birds visiting the European Union belong to three different populations (Scott & Rose). The first population, estimated at 20000 individuals, comprises the white-bellied birds of the race hrota, breeding in Greenland and northern Canada and wintering in Ireland. The second population, estimated at 5000 individuals, comprises the birds of the race hrota breeding on Svalbard and wintering in Denmark and north-eastern England. The third population, estimated at 300000 individuals, comprises the dark-bellied birds of the nominate race, breeding along the Russian coasts and wintering in Denmark, Germany, the Netherlands, south-western England and France. All three populations have undergone important fluctuations. The nominate race has experienced a 90% decline during the 1930’s following a disease of its foodplant, Zostera marina. It has started to recover since the 1950’s, and the increase is still in progress. The populations of Canada and Greenland have increased since the 1960’s and seem currently to be stable. The population of Svalbard dropped from about 40000-50000 to a mere 2000 at the end of the 1960’s, not only because of the disease of Zostera but also because of non sustainable hunting. Since the 1970’s it has recovered
Single wholly migratory population. Depart Russian tundras mid-August to 1st week September. Main route west along arctic coasts to White Sea, then overland to Gulfs of Finland and Bothnia. Passage through Baltic mid-September to early October; first arrivals Denmark late September but bulk October. Some stay Denmark and western Germany through November before moving on in colder weather; others go straight to winter quarters in Netherlands, south-east England, and west France, where peak numbers December-February. Return passage begins early March; most leave England and France by mid-April. Spring gatherings in Netherlands, Denmark and western Germany until main departures in mid-May; only stragglers after mid-June.
Literature
Title Historical changes in black brant Branta bernicla nigricans use on Humboldt Bay, California
Author(s): Jeffrey E. Moore & Jeffrey M. Black
Abstract: We examined 70 years (1931-2000) of black brant Br..[more]..
Source: Wildl. Biol. 12: 151-162
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Title The significance of female body stores for egg laying and incubation in Dark-bellied Brent Geese Branta bernicla bernicla
Author(s): Spaans B., van’t Hoff C.A., van der Veer W. & Ebbinge B.S.
Abstract: The probability of successful breeding by Brent ge..[more]..
Source: ARDEA 95 (1): 3-15
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Title Differences in migratory pattern and habitat choice between social classes of the Brent Goose Branta bernicla bernicla.
Author(s): Lambeck R.D
Abstract: Age ratio (% juveniles) counts of Brent Goose floc..[more]..
Source: ARDEA 78 (3): 426-440.
download full text (pdf)
Title The applicability of age ratio and brood size counts in population dynamic studies of the Brent Goose Branta bernicla bernicla.
Author(s): Lambeck R.D.
Abstract: In wintering Brent Geese, annual assessments of th..[more]..
Source: ARDEA 78 (3): 414-425.
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Title Food exploitation patterns by Brent Geese Branta bernicla during spring staging.
Author(s): Prop J.
Abstract: The exploitation pattern of a salt marsh community..[more]..
Source: ARDEA 79 (2): 331-341.
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Title Dark-bellied Brent Geese Branta bernicla bernicla in Britain, 1976-1987.
Author(s): Salmon D.G. & Fox A.D.
Abstract: The numbers of Dark-bellied Brent Geese wintering ..[more]..
Source: ARDEA 79 (2): 327-330.
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Title Regulation of numbers of Dark-bellied Brent Geese Branta bernicla bernicla on spring staging sites.
Author(s): Ebbinge B.S.
Abstract: The usage of the Boschplaat salt-marsh on Terschel..[more]..
Source: ARDEA 80 (2): 203-228
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Title The possible importance of nutritional requirements for Dark-bellied Brent Geese in the seasonal shift from winter cereals to pasture.
Author(s): Mckay H., Bishop J.D. & Ennis D.C.
Abstract: The use by Brent Geese of five pairs of winter cer..[more]..
Source: ARDEA 82 (1): 123-132.
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Title Dark-bellied Brent Geese Branta bernicla bernicla forego breeding when Arctic foxes Alopex lagopus are present during nest initiation
Author(s): Spaans B., Blijleven H., Popov I.U., Rykhlikova M.E. & Ebbinge B.S.
Abstract: In an area north of the Pyasina delta in Taimyr (R..[more]..
Source: ARDEA 86 (1): 11-20.
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Title Inland pastures are an appropriate alternative for salt-marshes as a feeding area for spring-fattening Dark-bellied Brent Geese Branta bernicla.
Author(s): Spaans B. & Postma P
Abstract: On the Dutch Wadden Sea island Texel, spring-fatte..[more]..
Source: ARDEA 89 (3): 427-440
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