Goose - biology. I INTRODUCTION Goose, a swimming bird with webbed feet and a long neck. Geese belong to the same family of waterfowl as ducks and swans. Geese are larger and have longer feet and necks than ducks. Geese are smaller and have shorter necks and legs than swans. Ducks are generally more colorful than geese, which tend to be brownish in color. Male and female geese look alike, although in some species the male is larger than the female. A male goose is called a gander, a female is called a goose, and a baby goose is called a gosling. II HABITAT AND MIGRATION OF GEESE Geese are found on bodies of fresh water and salt water in the northern hemisphere. Geese live in seas, lakes, bays, marshes, and ponds. The Canada goose, a familiar North American bird, can even be seen in yards, fields, parks, and golf courses. Geese spend more time on land than either ducks or swans because they feed largely by grazing on plants. Most geese are migratory, and they migrate in spring to nesting grounds in the far north. In fall they fly south to warmer wintering grounds. The Canada goose is a noted long-distance migrant, flying as much as 1,600 km (1,000 mi) from wintering grounds to breeding grounds near the Arctic Circle. Some Canada geese winter as far south as Mexico. Canada geese have been brought to Europe, where they breed in the United Kingdom and Scandinavia. Before migration geese fatten up for the long journey ahead. They also shed their feathers and grow a new set. A migrating flock may contain thousands of birds. Geese usually follow the same route, or flyway, year after year. They make several stops along the way to rest and eat, sometimes staying as long as several weeks at a favorite stopover. Family groups stick together within the migrating flock. The young travel with their parents to learn the way. During migration geese travel at speeds of 60 to 100 kilometers per hour (40 to 60 mph). During the 20th century the Canada goose expanded its breeding territory and lost much of its urge to migrate. Canada geese now nest in every state of the United States and every province of Canada. Wildlife refuges in the Midwestern United States have become popular wintering spots for Canada geese and other species. Some Canada geese have become permanent residents in urban areas where food is plentiful year-round. In some communities these geese are considered a nuisance because they are loud and messy. Because geese eat a lot, they also leave many droppings. III BEHAVIOR OF GEESE Geese are sociable animals and tend to gather in large groups in open areas during winter. During the day they fly in small groups to feeding grounds nearby. Geese feed on plants, especially grasses, grains, and seeds. They also eat the stems and roots of water plants. Geese are also wary. When they feed, one goose always keeps watch. The watcher honks to warn the others of any intruders. Geese also gather in flocks before migration, and the flock then travels together. Geese are excellent swimmers. They use their large webbed feet, in which the toes are connected by flaps of skin, and strong legs to propel themselves in water. Water-resistant outer feathers keep geese dry, and soft inner feathers, called down, trap air and keep geese warm and afloat in water. Geese preen often to keep their feathers clean and watertight. During preening they take oil on their bills from a preen gland near the base of their tail feathers. Then they rub the oil on their feathers. Geese are powerful flyers. Migrating geese fly in a V-formation. By flapping its wings, each goose in the V creates an updraft for the goose behind, thereby reducing the effort of flight. The lead goose in the V lacks this advantage. When the lead goose grows tired, it drops back and another goose takes its place at the front of the V. Some geese travel thousands of kilometers during migration. Flocks may contain thousands of geese. Geese are noisy birds. When flying they call to each other, and people far below on the ground can hear their honking. Male and female geese usually pair for life. Pairs generally form in winter, before migration. When the geese reach their breeding grounds, the female builds the nest from twigs on which she puts weeds, grass, or moss. She may pluck feathers from her breast to line the nest. The female lays from four to seven eggs, and she incubates the eggs until they hatch about four weeks later. The male defends the nest from predators. The female leaves the nest only briefly during incubation, and when she does, she pulls feathers over the eggs to keep them warm. Both parents look after the young. While the young feed, one parent remains on watch for danger or predators. Both parents care for the goslings. The young can swim within days after hatching, and they are able to fly in about 40 to 75 days. Goslings spend most of their time eating and gain weight rapidly. They must grow large enough to migrate south with their parents in the fall. While the young feed one parent remains on watch for danger or predators. Animals that prey on geese include small mammals, gulls, and other sea birds. Geese defend themselves against predators by hissing, biting, and striking the predators with their wings. The young geese migrate south with their parents to learn the route. Family groups usually stay together within the flock. The young remain with their parents for a year, until the next breeding season. Geese do not mate until they are two or three years old. IV KINDS OF GEESE Geese that live freely in nature are known as wild geese. Scientists classify wild geese into three genera (plural of genus) of "true geese" based on their physical characteristics. These genera are Branta, Anser, and Chen. Although some birds of the southern hemisphere are called geese, experts do not consider them true geese. They include the magpie goose and the Cape Barren goose of Australia and New Zealand, and the Magellan goose of southern South America and the Falkland Islands (Islas Malvinas). These geese belong to different genera, and unlike the true geese, the male and female of these species may differ in coloration. Geese that are bred for their feathers, meat, or eggs are called domestic geese. Nearly all domestic geese descend from the greylag goose, a member of the genus Anser. A Canada Geese and Related Species The Canada goose belongs to the genus Branta and is the most widespread member of the goose family. Canada geese vary in their size and color, and experts recognize a dozen subspecies. The birds measure from 65 to 115 cm (25 to 45 in) in length, with a wingspan of 110 to 150 cm (43 to 60 in). Although Canada geese are darker than others, all have bodies in some shade of brown; a black head, neck, and tail; and a white "chinstrap" that extends up onto their cheeks. The barnacle goose, another member of the genus Branta, is closely related to the Canada goose. It has a black neck and breast, greyish back, white cheeks, and whitish lower parts. The barnacle goose is native to Europe and rarely seen in North America. Branta comes from a German word meaning "burned" and all of the geese in this genus have black plumage somewhere on their bodies. The brant, a sea goose that also belongs to this genus, is found on both coasts of North America. Brants are darker than barnacle and Canada geese and similar in size to the smallest Canada geese. Like the Canada and barnacle goose, the brant nests in Arctic regions. But unlike them, it winters chiefly on salt water. Instead of the white cheeks of Canada and barnacle geese, adult brants have a white "necklace." The brant is known in Europe as the brent goose. The Hawaiian goose, or n?n ? also belongs to the Branta genus. The n?n? resembles the Canada goose in plumage but is smaller and spends all its time on land. Native to Hawaii and the emblem of the state, the n?n ? was saved from extinction through breeding in captivity. The bird's name, n? n?, describes the sound of its call. B Geese of the Genus Anser Members of the genus Anser include the white-fronted goose, the greylag goose, and the bar-headed goose. These geese are generally grayish in color and have pink or orange legs. The white-fronted goose is known in Europe as the laughing goose because of its high-pitched call. The greylag, the largest goose native to Europe, is widespread in Europe and Asia. This goose winters in southern Europe and northern Africa. The bar-headed goose has two brownish-black stripes across the top of its white head. This Asian goose migrates from Central Asia across the Himalaya to winter in India, Myanmar, and Pakistan. Bar-headed geese fly at higher altitudes than any other geese, facing cold and high winds. C Geese of the Genus Chen The emperor goose, the snow goose, and Ross's goose make up the genus Chen. These geese spend much of their lives in the far north and have white or pale gray bodies. The emperor goose is a white-headed, pale gray goose that breeds in the Bering Sea off the coast of Alaska and Russia. Its feathers have a black strip and then a white stripe at the tips, giving its body a scaly appearance. Snow geese come in two colors. Some are snow white with black wingtips. Others, once known as blue geese, are bluish-gray with a white head. Blue geese were long thought to belong to a separate species but are now known to be another color of snow goose. Snow geese and Ross's geese winter in the United States and Canada. Ross's goose is the smallest goose, measuring about 58 cm (23 in) in length. It looks like a tiny snow goose. Ross's goose is named for Bernard R. Ross, a business agent for the Hudson's Bay Company. D Domestic Geese Geese have been bred and raised as farm animals for their meat, eggs, and feathers for at least 3,000 years. Most domestic geese are descended from the greylag goose. Among the most important domestic geese are the Toulouse goose, an all-gray breed originating in France; the Embden, an all-white goose originating in Germany; and the African, a tall, gray goose that fattens more rapidly than any other breed. Geese are the source of the delicacy pâté de foie gras, made from goose livers that are abnormally enlarged by overfeeding (sometimes force feeding) the geese and then depriving them of exercise. Domestic geese are also commercially valuable for their feathers, which are used in pillows, insulated clothing, and sleeping bags. See also Poultry Farming. Scientific classification: Geese belong to the family Anatidae of the order Anseriformes. True geese belong to the genera Anser, Branta, and Chen. The greylag goose is classified as Anser anser, the white-fronted goose as A. albifrons, and the bar-headed goose as A. indicus. The Canada goose is classified as Branta canadensis, the barnacle goose as B. leucopsis, the brant as B. bernicla, and the n?n ? as B. sandvicensis. The emperor goose is classified as Chen canagica, the snow goose as C. caerulescens, and Ross's goose as C. rossii. The magpie goose is classified as Anseranas semipalmata, the Cape Barren goose as Cereopsis novaehollandiae, and the Magellan goose as Chloephaga picta. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
