Early History (barnacles and geese): Barnacle goose gets its name from the early belief that the birds were born of barnacles in the sea shores. This was because the residents of the British Isles could not explain why the birds showed up in the summer and were absent in the winter.
Additional Information: During migratory flight, the heart rate of the barnacle goose can go up to a high of 315 beats per minute and a low of 225 beats per minute.
Barnacle geese generate monosyllabic, rapid, loud calls to warn nearby geese of approaching predators. These calls often resemble the yapping of small dogs. They may generate loud calls to warn of aerial predators during flight as well.
Duets are usually performed during the mating season and serve the purpose of strengthening pair bonds between mates. A duet is often initiated by the male who makes short, rapid, loud calls. These calls are followed by similar loud calls from an interested female. Duets may also be initiated right after the initial mate selection in young barnacle geese. Vocal duets are often accompanied by visual displays by the male, who points his beak in alternating directions or holds his head close to the ground. If the female accepts his display, she allows him to approach and touch her with his bill.
During migration, barnacle geese are presumed to utilize magnetic fields to direct their flights.
Like most birds, barnacle geese perceive their environments through tactile, auditory, visual and chemical stimuli.
Communication Channels: visual ; tactile ; acoustic
Other Communication Modes: duets
Perception Channels: visual ; tactile ; acoustic ; chemical ; magnetic
Barnacle geese are considered Least Concern by the International Union for Conservation of Nature and Natural Resources' (IUCN) Red List. Population sizes range from a few thousand to well over 100,000 and they are protected throughout their range. The Barnacle Goose Management Scheme in Scotland, United Kingdom makes efforts to protect barnacle geese from persecution by farmers during the wintering periods when the geese are frequent visitors to croplands. This conservation group helps farmers to make their land more suitable to supporting barnacle geese and also gives financial rewards to those that refrain from disturbing the birds on their property.
CITES: no special status
IUCN Red List of Threatened Species: least concern
This species is known to be considered pests by farmers in the British Isles and Netherlands. Barnacle geese often graze farmlands during their wintering months and reduce the soil quality, preventing farmers from obtaining high yields from their crops in the summer and early fall.
Negative Impacts: crop pest
Until the late 18th century, barnacle geese were considered to be non-meat food sources (due to beliefs that they were grown from barnacles) and was edible during Lent. Outside of Lent, the species was also hunted and consumed during their wintering stay in the British Isles by the coastal human populations. Currently, hunting and consumption of barnacle geese is prohibited by many governing bodies in both the British Isles and the European Arctic regions.
The species acts as a seed-dispersant for many grasses and is also a prey item for other species such as peregrine falcons, polar bears, and Arctic foxes.
Ecosystem Impact: disperses seeds
The species is herbivorous and mainly feeds on grass, aquatic vegetation, or human agricultural crops. On their breeding grounds, they will eat vegetation that is available in the tundra. In their wintering grounds they will often occupy fields and farmlands to feed on grass. This often causes a conflict with farmers.
Plant Foods: leaves; roots and tubers
Primary Diet: herbivore (Folivore )
The species consists of four main migrant populations that utilize various wintering and breeding grounds. These main populations number in the tens of thousands with the largest consisting of well over 100,000 individuals. Other smaller populations have been identified but these populations number only in the few thousands. The wintering grounds of all of these populations are located in the British Isles and coastal Netherlands and are separated by relatively short distances, while their breeding grounds are widely separated in the northern European arctic. These four main populations range from their wintering grounds in northern Scotland to their breeding grounds on the east coast of Greenland:
Greenland population: This population consists of about 45,000 individuals. Their breeding grounds are located on the ice-free coasts of East Greenland. These individuals gather mostly on cliff ledges or on small islands that are close to the shores. In September, when the weather conditions in Greenland worsen, they head for their wintering grounds on the shores and islands of northern Scotland. On their way to Scotland, they make a stop at Iceland for about four weeks and then continue their migration.
Svalbard population: This population consists of about 25,000 individuals. They breed on the islands of the Svalbard archipelago and the small islands that surround it. They leave Svalbard in the middle of September and make a stop on the western coast of Norway before continuing on to their wintering grounds in Solway Firth on the west coast of England. This migration path is about 2,500 to 3,000 km in distance.
Russian population: This population consists of over 100,000 individuals. They breed on the north-west coast of arctic Russia. This population initially wintered in Western Germany, however due to increased interruption of wintering areas in Western Germany and the creation of new grazing areas in the coastal regions of Netherlands the entire population has had to shift their wintering grounds to the Netherlands.
Novaya Zemlya population: This population consists of about 10,000 individuals. They breed in the archipelago islands of Novaya Zemlya off the coast of western arctic Russian mainland. They migrate to the coastal regions of Netherlands to spend the winter.
Additionally, it is believed that an ancient population may also have lived on the north-east coast of Canada, however currently there is insufficient data to support this hypothesis.
Biogeographic Regions: nearctic (Native ); palearctic (Native )
Other Geographic Terms: holarctic
The species often occupies pasture land, salt marshes, and grassy fields near the coastal regions of the European arctic and the British Isles. Although conservation efforts have allowed the generation of designated areas from which the species can benefit, they have been known to graze in farming and suburban areas. During the breeding season, females are known to construct their nests in rocky areas on hillsides. Areas with an abundance of tundra vegetation, coastal dunes, and marshes are preferred by this species.
Range elevation: 0 to 40 m.
Average elevation: 15 m.
Habitat Regions: temperate ; polar ; terrestrial
Terrestrial Biomes: tundra
Wetlands: marsh
Other Habitat Features: suburban ; agricultural
In the wild, Branta leucopsis may live up to 25 years of age. In captivity where they are protected from predators and are provided sufficient food, they may live up to 30 years of age.
Range lifespan
Status: wild: 18 to 25 years.
Range lifespan
Status: captivity: 24 to 30 years.
Typical lifespan
Status: wild: 20 to 23 years.
Typical lifespan
Status: captivity: 23 to 28 years.
Branta leucopsis in adult plumage has a rounded body, a rounded head, and a relatively short neck. The white feathers on the head cover a greater portion of the face than that of Branta canadensis (Canada goose). Overall, the face patch is white or often creamy-white and also extends to the forehead and under the throat. The black coloration of the neck extends below the chest. The ventrum of this species is white colored towards the posterior end and light-gray colored towards the anterior side. A black colored thin strip of feathers joins the eye and the bill. The feet are entirely black colored. The dorsal feathers are dark, bluish-grey. The tail is completely black both on its dorsal and ventral sides. The bill is black colored and short. The feather coloration above the wing is dark grey while the coloration below the wing is light, silvery-grey and white. Plumage is the same in both males and females of the species. However, males are usually larger in body size and weight than females. Adults weigh between 1.4 and 2.2 kg and feature a wingspan of 130 to 145 cm. Body length ranges from 55 to 70 cm.
Young adult barnacle geese (in their first winter) look very much the same as adults with slight plumage color variations. The black feathers of the neck and chest will often have a duller color compared to those of adults. It is possible to see a few brown feathers in the neck region as well. The faces of young birds may have few dark fleckings which can be hard to detect from a distance.
Downy young barnacle geese have grey-brown feathers on their dorsal parts, neck, chest, and crown. The ventrum of the downy young is pale-yellow. The line of feathers that extends from the bill to the eye is dark-grey colored. The feet and the bill are dark-grey colored as well. White spots are common on the wings.
Variation of plumage in adults has been observed but is rare. Adults with entirely dark brown to entirely white feathers have been observed in the past.
Range mass: 1.4 to 2.2 kg.
Average mass: 1.9 kg.
Range length: 55 to 70 cm.
Average length: 64 cm.
Range wingspan: 130 to 145 cm.
Average wingspan: 141 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; male larger
During the breeding season in the arctic, top predators of this species are polar bears and Arctic foxes. Barnacle geese parents are known to aggressively physically defend their nests and young. Peregrine falcons are also known to hunt this species. During flight, if barnacle geese are threatened by aerial predators such as peregrine falcons, the flock adopts initiate fast turns in synchrony to confuse the attacker and avoid predation.
Known Predators:
Barnacle geese that have reached sexual maturity will choose their partners in early spring. Partner retention in Branta leucopsis is lifelong and monogamous. This partnership is believed to be established with a triumph ceremony in which the male will vocalize and change postures to impress the female. During this ceremony, the male will make loud calls and change the orientation and angle of his head relative to ground. If the female is willing to participate, she responds with loud calls and the male will increase the intensity of his movements and later try to approach the female. At times during the triumph ceremony, if a male catches the attention of a nearby female, he may exaggerate his displays by flicking his wings and lowering his head closer and more parallel to the ground. The goal of the male in this ceremony is to make contact with the female with his bill. If the female does not draw herself away, the male takes it as a sign of acceptance and forces all nearby males away. It is also believed that pairs may engage in the triumph ceremony each year to strengthen their partnership.
Mating System: monogamous
The breeding season occurs in spring, spanning from late May to June. Barnacle geese reaches sexual maturity at two years of age. However, rarely, males will be observed breeding at one year of age with females that are older. Barnacle geese that have mated for the first time at four years of age have also been recorded. It is believed that the age in which these geese mature may be related to environmental factors such as food availability and overall weather conditions. The female usually lays one egg per day until the desired clutch size (4 to 5 eggs) can be obtained. These eggs are pale gray colored. The clutch is incubated for 24 to 26 days and the young typically fledge 40 days after hatching.
Breeding interval: Barnacle geese breed once a year in spring.
Breeding season: Breeding occurs in the spring, usually between late May and June.
Range eggs per season: 3 to 6.
Average eggs per season: 4 to 5.
Range time to hatching: 24 to 26 days.
Range fledging age: 40 to 45 days.
Average age at sexual or reproductive maturity (female): 2 years.
Range age at sexual or reproductive maturity (male): 1 (low) years.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Nests are constructed by females, often on cliff edges to avoid predators such as the arctic fox (Vulpes lagopus). Nest building materials include mud and dead foliage. Prior to laying her eggs the female lines the nest with down. The female will incubate the eggs for 24 to 26 days. During this time, the male will guard the nest and the female. During the incubation period, it is energetically costly to incubate and defend the eggs as the parents cannot forage far away from the nest. This causes both the female and the male to lose 30% to 40% of their total body weight. Barnacle goose hatchlings are precocial and leave the nest as soon as their downy feathers have dried. Parents lead their brood to marshes with abundant vegetation, but the young are entirely responsible for feeding themselves. The young are aggressively defended by both parents until they fledge and become independent after 40 to 45 days. Families remain together even after the young are considered independent. These family groups will perform their first migration together to the wintering grounds, but will disperse before the following breeding season as parents become increasingly territorial.
Parental Investment: precocial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Protecting: Male, Female); pre-independence (Protecting: Male, Female); post-independence association with parents
Accidental visitor.
The barnacle goose (Branta leucopsis) 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 barnacle goose was first classified taxonomically by Johann Matthäus Bechstein in 1803. Branta is a Latinised form of Old Norse Brandgás, "burnt (black) goose" and the specific epithet is from the Ancient Greek leukos "white", and opsis "faced".[2]
The barnacle goose and the similar brant goose were previously considered one species, and were formerly believed to spawn from the goose barnacle.[3] This gave rise to the English name of the barnacle goose and the scientific name of the brant.[2] It is sometimes claimed that the word comes from a Celtic word for "limpet", but the sense-history seems to go in the opposite direction.[4]
The barnacle 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. The legend persisted until the end of the 18th century. In County Kerry, until relatively recently, Catholics abstaining from meat during Lent could still eat this bird because it was considered as fish.[5]
The barnacle goose is a medium-sized goose, 55–70 cm (22–28 in) long,[6] with a wingspan of 130–145 cm (51–57 in) and a body mass of 1.21–2.23 kg (2.7–4.9 lb).[7][8] It has a white face and black head, neck, and upper breast. Its belly is white. The wings and its back are silver-gray with black-and-white bars that look like they are shining when the light reflects on it. During flight, a V-shaped white rump patch and the silver-gray underwing linings are visible.
Barnacle geese breed mainly on the Arctic islands of the North Atlantic. There are five populations, with separate breeding and wintering ranges - from west to east:
Small numbers of feral birds, derived from escapes from zoo collections, also breed in other Northern European countries. Occasionally, a wild bird will appear in the Northeastern United States or Canada, but care must be taken to separate out wild birds from escaped individuals, as barnacle geese are popular waterfowl with collectors.
Barnacle geese frequently build their nests high on mountain cliffs, away from predators (primarily Arctic foxes and polar bears), but also away from their feeding grounds such as lakes, rivers. Like all geese, the goslings are not fed by the adults. Instead of bringing food to the newly hatched goslings, the goslings are brought to the ground. The parents show them the way to jump from the cliff and the goslings follow them by instincts and take the plunge.
Unable to fly, the goslings, in their first days of life, jump off the cliff and fall; their small size, feathery down, and very light weight helps to protect some of them from serious injury when they hit the rocks below, but many die from the impact. Arctic foxes are attracted by the noise made by the parent geese during this time, and capture many dead or injured goslings. The foxes also stalk the young as they are led by the parents to wetland feeding areas.[11] Due to these hardships only 50% of the chicks survive the first month.[12]
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Brooding in Sweden
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Pair with goslings in Sweden
Juvenile
Flock on autumn migration
The barnacle goose is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds applies.[13] According to Sveriges ornitologiska förening, the geese began breeding in Sweden in 1971, and according to Skansen, it was 40 years ago, more or less, when the entire population of barnacle geese left in the autumn to return in spring, soon after they began breeding in the wild. The number of barnacle geese is stable to increasing.[14]
The natural history of the barnacle goose was long surrounded with a legend claiming that they were born of driftwood:
Nature produces [Bernacae] against Nature in the most extraordinary way. They are like marsh geese but somewhat smaller. They are produced from fir timber tossed along the sea, and are at first like gum. Afterwards they hang down by their beaks as if they were a seaweed attached to the timber, and are surrounded by shells in order to grow more freely. Having thus in process of time been clothed with a strong coat of feathers, they either fall into the water or fly freely away into the air. They derived their food and growth from the sap of the wood or from the sea, by a secret and most wonderful process of alimentation. I have frequently seen, with my own eyes, more than a thousand of these small bodies of birds, hanging down on the sea-shore from one piece of timber, enclosed in their shells, and already formed. They do not breed and lay eggs like other birds, nor do they ever hatch any eggs, nor do they seem to build nests in any corner of the earth.[15]
The legend was widely repeated in, for example, Vincent of Beauvais's great encyclopedia. However, it was also criticized by other medieval authors, including Albertus Magnus.[15]
This belief may be related to the fact that these geese were never seen in summer, when they were supposedly developing underwater (they were actually breeding in remote Arctic regions) in the form of barnacles—which came to have the name "barnacle" because of this legend.[16]
Based on these legends—indeed, the legends may have been invented for this purpose[17]—some Irish clerics considered barnacle goose flesh to be acceptable fast day food, a practice that was criticized by Giraldus Cambrensis, a Welsh author:
...Bishops and religious men (viri religiosi) in some parts of Ireland do not scruple to dine off these birds at the time of fasting, because they are not flesh nor born of flesh... But in so doing they are led into sin. For if anyone were to eat of the leg of our first parent (Adam) although he was not born of flesh, that person could not be adjudged innocent of eating meat.[15]
At the Fourth Council of the Lateran (1215), Pope Innocent III explicitly prohibited the eating of these geese during Lent, arguing that despite their unusual reproduction, they lived and fed like ducks and so were of the same nature as other birds.[18]
The question of the nature of barnacle geese also came up as a matter of Jewish dietary law in the Halakha, and Rabbeinu Tam (1100–71) determined that they were kosher (even if born of trees) and should be slaughtered following the normal prescriptions for birds.[15]
In one Jewish legend, the barnacle goose is purported to have its beak forever attached to the tree from which it grew just as the Adne Sadeh is fixed to the earth by its navel cord.[19] The mythical barnacle tree, believed in the Middle Ages to have barnacles that opened to reveal geese, may have a similar origin to the other legends already mentioned.[20]
Goose barnacles turning into barnacle geese in Sebastian Münster's 1552 Cosmographia
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Autumn migration in Sweden
A flock feeding at Helsinki, Finland
The barnacle goose (Branta leucopsis) 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.
