Greylag goose

"Greylag" redirects here. For the Thoroughbred race horse, see Grey Lag. For the Admirable-class minesweeper, see USS Graylag (AM-364).
Greylag goose
Anser anser
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Subfamily: Anserinae
Tribe: Anserini
Genus: Anser
Species: A. anser
Binomial name
Anser anser
(Linnaeus, 1758)
Subspecies
  • A. a. anser (Linnaeus, 1758)
    Western greylag goose
  • A. a. rubrirostris Swinhoe, 1871
    Eastern greylag goose
  • A. a. domesticus (Kerr, 1792)
    Domesticated goose
Green: breeding, orange: non-breeding, red: introduced
Synonyms

Anas anser Linnaeus, 1758

Greylag geese, Texel, Netherlands (2009)
Greylag geese feding. Ystad. 19 feb 2016.

The greylag goose (Anser anser) is a bird in the waterfowl family Anatidae. It has mottled and barred grey and white plumage and an orange beak and legs. A large bird, it measures between 74 and 91 centimetres (29 and 36 in) in length, with an average weight of 3.3 kilograms (7.3 lb). Its distribution is widespread, with birds from the north of its range in Europe and Asia migrating southwards to spend the winter in warmer places. It is the type species of the genus Anser and is the ancestor of one type of domestic goose, having been domesticated at least as early as 1360 BC. The genus name is from anser, the Latin for "goose".[2]

Greylag geese travel to their northerly breeding grounds in spring, nesting on moorlands, in marshes, around lakes and on coastal islands. They normally mate for life and nest on the ground among vegetation. A clutch of three to five eggs is laid; the female incubates the eggs and both parents defend and rear the young. The birds stay together as a family group, migrating southwards in autumn as part of a flock, and separating the following year. During the winter they occupy semi-aquatic habitats, estuaries, marshes and flooded fields, feeding on grass and often consuming agricultural crops.

Taxonomy

Anser anser, the greylag goose, is a member of the waterfowl family Anatidae. It was first described by the Swedish naturalist Carl Linnaeus in 1758 as Anas anser, but was transferred two years later to the new genus Anser, erected by the French zoologist Mathurin Jacques Brisson, where it is the type species. Two subspecies are recognised; A. a. anser, the western greylag goose, breeds in Iceland and north and central Europe; A. a. rubrirostris, the eastern greylag goose, breeds in Romania, Turkey and Russia eastwards to northeastern China. The two subspecies intergrade where their ranges meet. The greylag goose sometimes hybridises with other species of goose including the barnacle goose (Branta leucopsis) and the Canada goose (Branta canadensis), and occasionally with the mute swan (Cygnus olor).[3] The greylag goose was one of the first animals to be domesticated; this happened at least 3000 years ago in Ancient Egypt, the domestic breed being known as A. a. domesticus.[4]

Description

The greylag is the largest and bulkiest of the grey geese of the genus Anser, but is more lightly built and agile than its domestic relative. It has a rotund, bulky body, a thick and long neck, and a large head and bill. It has pink legs and feet, and an orange or pink bill with a white or brown nail (hard horny material at tip of upper mandible).[5] It is 74 to 91 centimetres (29 to 36 in) long with a wing length of 41.2 to 48 centimetres (16.2 to 18.9 in). It has a tail 6.2 to 6.9 centimetres (2.4 to 2.7 in), a bill of 6.4 to 6.9 centimetres (2.5 to 2.7 in) long, and a tarsus of 7.1 to 9.3 centimetres (2.8 to 3.7 in). It weighs 2.16 to 4.56 kilograms (4.8 to 10.1 lb), with a mean weight of around 3.3 kilograms (7.3 lb). The wingspan is 147 to 180 centimetres (58 to 71 in).[6][7][8] Males are generally larger than females, with the sexual dimorphism more pronounced in the eastern subspecies rubirostris, which is larger than the nominate subspecies on average.[5]

The plumage of the greylag goose is greyish-brown, with a darker head and paler breast and belly with a variable amount of black spotting. It has a pale grey fore-wing and rump which are noticeable when the bird is in flight or stretches its wings on the ground. It has a white line bordering its upper flanks, and its wing coverts are light-coloured, contrasting with its darker flight feathers. Its plumage is patterned by the pale fringes of the feathers. Juveniles differ mostly in their lack of black-speckling on the breast and belly and by their greyish legs.[5][9]

The greylag goose has a loud cackling call similar to that of the domestic goose, "aahng-ung-ung", uttered on the ground or in flight. There are various subtle variations used under different circumstances, and individual geese seem to be able to identify other known geese by their voices. The sound made by a flock of geese resembles the baying of hounds.[10] Goslings chirp or whistle lightly, and adults hiss if threatened or angered.[5]

Distribution and habitat

This species has a Palearctic distribution. The nominate subspecies breeds in Iceland, Norway, Sweden, Finland, the Baltic States, northern Russia, Poland, eastern Hungary and Romania. It also breeds locally in the United Kingdom, Denmark, Germany, Austria, the Czech Republic, Slovakia and Macedonia. The eastern race extends eastwards across a broad swathe of Asia to China.[10] European birds migrate southwards to the Mediterranean region and North Africa. Asian birds migrate to Baluchistan, Azerbaijan, Iran, Pakistan, northern India, Bangladesh and eastward to China.[10]> In North America, there are both feral domestic geese, which are similar to greylags, and occasional vagrant greylags.[9] Greylag geese seen in the wild in New Zealand probably originated from the escape of farmyard geese,[11] and a similar thing has happened in Australia where feral birds are now established in the east and southeast of the country.[12]

In their breeding quarters, they are found on moors with scattered lochs, in marshes, fens and peat-bogs, besides lakes and on little islands some way out to sea. They like dense ground cover of reeds, rushes, heather, bushes and willow thickets. In their winter quarters, they frequent salt marshes, estuaries, freshwater marshes, steppes, flooded fields, bogs and pasture near lakes, rivers and streams. They also visit agricultural land where they feed on winter cereals, rice, beans or other crops, moving at night to shoals and sand-banks on the coast, mud-banks in estuaries or secluded lakes.[10] Large numbers of immature birds congregate each year to moult on the Rone Islands near Gotland in the Baltic Sea.[13]

In Great Britain, their numbers had declined as a breeding bird, retreating north to breed wild only in the Outer Hebrides and the northern mainland of Scotland. However, during the 20th century, feral populations have been established elsewhere, and they have now re-colonised much of England. These populations are increasingly coming into contact.[14]

Behaviour

In a group, many pairs of eyes are on watch.

Greylag geese are herbivorous and feed chiefly on grasses. Short, actively growing grass is more nutritious and greylag geese are often found grazing in pastures with sheep or cows.[15] Because of its low nutrient status, they need to feed for much of their time; the herbage passes rapidly through the gut and is voided frequently.[16] The tubers of sea clubrush (Bolboschoenus maritimus) are also taken as well as berries and water plants such as duckweed (Lemna) and floating sweetgrass (Glyceria fluitans). In wintertime they eat grass and leaves but also glean grain on cereal stubbles and sometimes feed on growing crops, especially during the night. They have been known to feed on oats, wheat, barley, buckwheat, lentils, peas and root crops. Acorns are sometimes consumed, and on the coast, seagrass (Zostera sp.) may be eaten.[10] In the 1920s in Britain, the pink-footed goose "discovered" that potatoes were edible and started feeding on waste potatoes. The greylag followed suit in the 1940s and now regularly searches for tubers on ploughed fields.[13]

These geese normally pair for life, so courtship only occurs at the time of first maturity. The nest is on the ground among heather, rushes, dwarf shrubs or reeds, or on a raft of floating vegetation. It is built from pieces of reed, sprigs of heather, grasses and moss, mixed with small feathers and down. A typical clutch is four to six eggs, but fewer eggs or larger numbers are not unusual. The eggs are creamy-white at first but soon become stained, and average 85 by 58 millimetres (3.3 by 2.3 in). They are mostly laid on successive days and incubation starts after the last one is laid. The female does the incubation, which lasts about twenty-eight days, while the male remains on guard somewhere near. The chicks are precocial and able to leave the nest soon after hatching. Both parents are involved in their care and they soon learn to peck at food and become fully-fledged at eight or nine weeks,[10] about the same time as their parents regain their ability to fly after moulting their main wing and tail feathers a month earlier.[15] Immature birds undergo a similar moult, and move to traditional, safe locations before doing so because of their vulnerability while flightless.[15]

A migrating flock

Greylag geese are gregarious birds and form flocks. This has the advantage for the birds that the vigilance of some individuals in the group allows the rest to feed without having to constantly be alert to the approach of predators. After the eggs hatch, some grouping of families occur, enabling the geese to defend their young by their joint actions, such as mobbing or attacking predators.[15] After driving off a predator, a gander will return to its mate and give a "triumph call", a resonant honk followed by a low-pitched cackle, uttered with neck extended forward parallel with the ground. The mate and even unfledged young reciprocate in kind.[10]

Young greylags stay with their parents as a family group, migrating with them in a larger flock, and only dispersing when the adults drive them away from their newly established breeding territory the following year.[16] At least in Europe, patterns of migration are well understood and follow traditional routes with known staging sites and wintering sites. The young learn these locations from their parents which normally stay together for life.[13] Greylags leave their northern breeding areas relatively late in the autumn, for example completing their departure from Iceland by November, and start their return migration as early as January. Birds that breed in Iceland overwinter in the British Isles; those from Central Europe overwinter as far south as Spain and North Africa; others migrate down to the Balkans, Turkey and Iraq for the winter.[17]

In human culture

Ancient Egyptian stele showing Amun-Ra as goose, man, and ram. 25th dynasty, c. 700 B.C.

The greylag was once revered across Eurasia. It was linked with the goddess of healing, Gula, a forerunner of the Sumerian fertility goddess Ishtar, in the cities of the Tigris-Euphrates delta over 5,000 years ago.[18] In Ancient Egypt, geese symbolised the sun god Ra. In Ancient Greece and Rome, they were associated with the goddess of love, Aphrodite, and goose fat was used as an aphrodisiac. Since they were sacred birds, they were kept on Rome's Capitoline Hill, from where they raised the alarm when the Gauls attacked in 390 B.C.[18]

Wood engraving "The Tame Goose, Anas anser" by Thomas Bewick, A History of British Birds, 1804

The goose's role in fertility survives in modern British tradition in the nursery rhyme Goosey Goosey Gander, which preserves its sexual overtones ("And in my lady's chamber"), while "to goose" still has a sexual meaning.[18] The tradition of pulling a wishbone derives from the tradition of eating a roast goose at Michaelmas, where the goose bone was once believed to have the powers of an oracle. For that festival, in Thomas Bewick's time, geese were driven in thousand-strong flocks on foot from farms all over the East of England to London's Cheapside market, covering some 8 or 9 miles (13 or 14 km) per day. Some farmers painted the geese's feet with tar and sand to protect them from road wear as they walked.[18]

Greylag geese were domesticated by at least 1360 B.C., when images of domesticated birds resembling the Eastern race, Anser anser rubirostris (which like modern farmyard geese, but unlike Western greylags, have a pink beak) were painted in Ancient Egypt. Goose feathers were used as quill pens, the best being the primary feathers of the left wing, whose "curvature bent away from the eyes of right-handed writers".[19] The feathers also served to fletch arrows.[18] In ethology, the greylag goose was the subject of Konrad Lorenz's pioneering studies of imprinting behaviour.[20]

Gallery

References

  1. ↑ BirdLife International (2012). "Anser anser". IUCN Red List of Threatened Species (IUCN) 2012: e.T22679889A40116131. Retrieved 11 November 2015.
  2. ↑ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 48. ISBN 978-1-4081-2501-4.
  3. ↑ Carboneras, Kirwan & Garcia 2014.
  4. ↑ Hugo, Susanne (2002). "Chapter 1: Origins and Breeds of Domestic Geese". In Buckland, Roger; Guy, Gérard. Geese: the underestimated species. FAO Agriculture Department. ISSN 0254-6019.
  5. 1 2 3 4 Madge & Burn 1988, pp. 140–141
  6. ↑ Dunning 1992
  7. ↑ Ogilvie & Young 2004
  8. ↑ "Greylag Goose". oiseaux-birds.com. Retrieved 17 October 2011.
  9. 1 2 Johnsgard 2010, p. 60
  10. 1 2 3 4 5 6 7 Witherby 1943, pp. 149-186.
  11. ↑ Southey, I.; Miskelly, C.M. (ed.) (2013). "Greylag goose". New Zealand Birds Online. Retrieved 24 October 2015.
  12. ↑ "Greylag goose". Gaia Guide. Retrieved 24 October 2015.
  13. 1 2 3 Alerstam & Christie 1993, pp. 90–96.
  14. ↑ Mitchell, Carl; Hearn, Richard; Stroud, David (4 September 2012). "The merging of populations of Greylag Geese breeding in Britain". British Birds. Archived from the original on 23 February 2014. Retrieved 17 November 2013.
  15. 1 2 3 4 Scheiber et al. 2013, pp. 9–10.
  16. 1 2 "Greylag goose (Anser anser)". Wildscreen Arkive. Retrieved 20 October 2015.
  17. ↑ "Greylag Goose ( Anser anser ) movements" (PDF). British Trust for Ornithology. Retrieved 24 October 2015. stated to be from Delany, S., Veen, J. & Clark, J.A., ed. (2006). Urgent preliminary assessment of ornithological data relevant to the spread of Avian Influenza in Europe. Report to the European Commission. Study contract: 07010401/2005/425926/MAR/B4.
  18. 1 2 3 4 5 Cocker & Mabey 2005, pp. 74–76.
  19. ↑ Rowland 1978, p. 69.
  20. ↑ Allen & Bekoff 1999, pp. 30–31.

Works cited

External links

Wikimedia Commons has media related to Greylag Goose.
Wikispecies has information related to: Anser anser
This article is issued from Wikipedia - version of the Thursday, April 28, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.