Saturday, 2 February 2013

Canada Goose

order : Anseriformes      Genus & Species : Anatidae     Family : Branta canadensis

Each fall, Canada geese take to the air and fly in undulating V-shaped formations as they follow their migratory flyways south across the North American continent. Warmed by dense plumage in the cold skies, the high-flying Canada goose travels thousands of miles each year on migration. They found across northern North America; winters farther south in the U.S. and Mexico; introduced into Britain, Scandinavia and New Zealand. 

Habitat : The Canada goose is an open-country bird, breeding in a variety of freshwater wetlands, from the tundra belt to plains, swamps and lakeside pastures. In winter, the goose favors cultivated fields, estuaries and coastal marshes. Where it has been introduced in Europe and the U.S., it has colonized parks, farmland, reservoirs and golf courses. These birds are generally nonmigratory, although some move locally each year. They are creating problems as populations are out of control. 
Food & Feeding : The Canada goose is a grazer. It eats a wide variety of plant parts (leaves, stems, roots, rhizomes, fruits and seeds). It feeds mostly on land, although it will also feed in water, upending like a duck to reach juicier growth. A common target for hunters in parts of its range, the goose has learned to be wary, especially while feeding. A grazing flock always has sentry birds alert and scanning for danger. Flights to the feeding grounds are made at sunrise, the geese arriving in family parties one after another — sometimes an entire field may be covered by birds. Largest concentrations are found in wildlife refuges and on arable farmland; birds raid cereal crops and cause further damage by compacting the soil with their feet. Changes in agricultural methods have led to increased availability of food in northern areas; this is thought to be one reason why many geese don’t migrate as far south as they did in previous decades. 
Behavior : Bird migration is both a marvel and a mystery, and it’s still not fully understood how the flocks of Canada geese find their way to the same areas every year. They probably use a range of navigational aids, including landmarks, the sun and stars and their own built-in sensitivity to the Earth’s magnetic field. Birds that nest in the far north travel the longest distances. Some Arctic breeders fly more than 3,000 miles to winter around the Gulf of Mexico, more southerly populations migrate only a few hundred miles and some not at all. Northbound geese fly in smaller flocks over a longer period; their journey is less dramatic than the mass migration in autumn. 
Breeding : The Canada goose mates for life, selecting its partner at the wintering grounds. Courtship involves neck movements and honking duets. This routine is repeated annually, even by established pairs. The nest (a waterside pile of vegetation lined with down) is built by the female, who also incubates the eggs. Her mate fiercely defends the nest against rivals until the eggs hatch. Then both parents are devoted to protecting their brood wherever they roam. A gosling nibbles plants and eats insects until it is strong enough to graze properly. 

Bill : Toothlike serrations along the edges of the upper and lower mandibles of the bill help the goose grip plants. 
Neck : The long neck enables the Canada goose to reach down for food underwater, when it upends like a duck or a swan. 
Plumage : Insulating plumage keeps the bird warm in northern latitudes and while flying at high altitudes.The goose sheds all its primary (wingtip) feathers simultaneously and so becomes flightless during its annual molt. 
Feet : Typical of most waterfowl, the three front toes are connected by webbing to provide power while swimming. 

Weight : 3–11 lbs.
Length : 22-44"
Wingspan : 4-6'
Sexual Maturity : 2-3 years
Breeding Season : March–July 

During its marathon migration, the goose cruises at about 4 mph, usually at altitudes up to 3,300'. On occasion, the bird has been known to fly over mountains 12,045' high. The bond between a pair of Canada geese is so strong that if one is injured during migration, its partner will stay behind with it.

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