Hej hugobot
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Du kan selv søge nemt på nettet: i øverste linie (adresse) skriver du fx "#canadagås" og så kommer der en masse links, du kan trykke på.
Håber du kan læse engelsk, for jeg har kopieret en god artikle til dig!
Men nu må du hellere få lukket dine gamle spørgsmål om canadagåsen!
Mvh, Christina
Canadagås
Canada Goose
Branta Canadensis
Den største af vores jagtbare gæs, som kan jages på træk og det er også muligt at komme til den i motorbåd.
Den største del af Canadagæssene forekommer i Østdanmark.
Canadagåsen forekommer næsten kun som træk fugl og de første fugle plejer at ankomme i november og med den største koncentration i december.
http://www.strandoghavjagt.dk/Aenderne/Gaes.htm
Nearctic: Canada Geese are found throughout North America. The specific areas in which these bird are found depends on the subspecies. These geographic locations can be divided into four groups; the Southern, Northern, Western and Aleutian-Canada populations. The Southern population ranges from 60 degrees North latitude to the Rockies and Atlantic. The Northern population ranges north of 60 degrees North latitude in the arctic and subarctic. They then travel to the southern parts of the United States during the winter. The Western population is found in the eastern coasts of Alaska and British Columbia. Lastly, the Aleutian-Canada population is rarely found. A general trend in all subspecies is that they all summer in the northern parts of North America in Canada and migrate south to areas of the United States in the winter months. (Ogilvie, 1978;Owen, 1980)
^ Physical Characteristics
Mass: 4 to 1 kg.
Branta canadensis have a black neck, bill and head with occasional white patches and a white strap under the chin. The body is usually brownish-gray although colors vary in some of the subspecies. In some of the smaller subspecies the body is dark brown in color where as in some of the larger subspecies, the body is a light gray tone. Underneath, the colors are much lighter and almost white on the tail. Durring flight the tail shows a white semi-circle just above the black tail. These color patterns are unique to the Canada Goose. Females may be slightly smaller than the males, although both are similar to each other in color pattern. The bill of Branta canadensis tapers from the base where it is high to the end where it has narrowed. The bill has lamellae, or teeth around the outside that are a used as a cutting tool. The legs are close together with very black feet. This goose has very large wings that can also be used as weapons. The weight of Branta canadensis also varies depending on the subspecies. There are larger subspecies that weigh about 9 pounds and smaller subspecies that only weigh 3 pounds.
Goslings, or baby Canada Geese, are yellow with some greenish-gray colorings on the top of the head and back. As with the adult color pattern, there are some variation among the different subspecies. The darker subspecies goslings have a brownish olive or blunt yellow coloring while those of lighter subspecies are lighter and brighter in color. These colors fade as the gosling grows into the adult color pattern. All goslings have black or blue-gray bills and legs and become darker as juveniles and adults.
(Kortright, 1942;Owen, 1980;Van Wormer, 1968)
^ Natural History
^ Food Habits
When on land, Branta canadensis eat a variety of grasses including Bermuda grass, salt grass and wild barley. Geese are able to grab a hold of each blade and pull it out with their bills by jerking their heads. They also eat wheat, beans, rice, and corn. In the water, the birds stick their head and upper part of their body into the water leaving their tail and back end extending in the air. They stretch their neck out, under the water, and slide their bills across the bottom silt. They also eat a number of aquatic plants such as eel grass, sea lettuce and sago. (Canadian Geese website;Owen, 1980;Van Wormer, 1968)
^ Reproduction
Females start laying eggs during the first weeks of March and continue as late as June in parts of the Arctic. Each egg takes a day and a half to be laid. The average clutch sizes are five eggs although this size ranges from 2 to 9 eggs. The incubation period lasts 25 to 28 days. The female incubates the eggs while the male protects the territory and stays nearby to call a warning if danger approaches. Incubation must occur immediately after the last eggs are laid. The female turns the eggs regularly to maintain the heat necessary to allow for hatching. The offspring hatches via an egg tooth on top of its beak to crack open the shell. Goslings keep cracking open the shells until they are completely free between 24 and 48 hours later. All of the eggs in the clutch are fully hatched with in 24 hours. The goslings with in a clutch usually have a sex ratio that is fifty-fifty. (Van Wormer, 1968;Canada Geese, Branta canadensis website, 1998)
^ Behavior
Males in this species are more aggressive than females. The bills are used not only for eating, but also in attacks and grooming. These birds take to flight when danger approaches. They also lay out flat and still on the ground with their necks stretched out to be less visible to the danger.
Canadian Geese have good eyesight, which is necessary for flight. They must move their heads in order to see out of their eyesight range. However, their eyes are close to their crowns on the side of their heads, enabling them to see more than 180 degrees (closer to 270 degrees) horizontally and vertically. They have mostly monocular vision. Canadian Geese have excellent hearing and the ears are located on the side of its head.
During warm days of the year, geese flatten their feathers against their body to reduce the dead air space and keep them cool. On cold days, they fluff their feathers to increase their insulating ability.
They are seldom found alone and communicate constantly with many sounds. They fly in flocks in the form of a "V" or a diagonally straight line to minimize the effort for the birds following the leader. Each bird doesn't fly directly behind the others, but off to an angle. They migrate at a slow pace, stopping along the way. Because of this pace, they arrive at the breeding grounds in good physical shape. Most geese mate for life. They form pairs during migration or on wintering grounds. Males fight over females with their wings and bills. The winner approaches the female with his head down and neck undulating. He makes hissing and honking noises. The pairs mate either before or after they have found a nesting location. Mating, occurs in the spring on the water. The female is usually partially submerged or completed submerged while copulation takes place. Older geese tend to return to the same breeding territory each year. The female chooses the location for nesting and even builds the nest without the male. The males defend the territory, nest, and eggs from intruders, such as other geese. The female has to leave the nest to eat, rest, swim and preen. Unguarded nests and eggs are targets for predators such as gulls, ravens, crows, skunks, dogs, and many others. The male sends out an alarm by flying into the air and honking as a predator approaches. This alerts not only his mate but others nesting nearby. Females lower their bodies onto the nest and stretches out their necks to camouflage the nest. After the eggs hatch, the family group (the offspring and parents) leave the nest for good and start to travel to their summer locations.
These birds love to swim and bathe in the water, especially on warm days. The Geese swim and flap around and sometimes completely submerge themselves.
Some subspecies have a yearly molt of flight feathers in the summer and become flightless during this time.
Migrations begin in the fall. Large winter aggregations form while on lakes, coastal waters, and mudflats. (Canada Geese, Branta canadensis website, 1998;Canadian Geese website;Owen, 1980;Van Wormer, 1968)
^ Habitat
When females pick a nesting site, they look for a place that has good visibility but is still isolated so they have a warning of danger and protection if danger approaches. The area also must have open water with low banks so they can have access to aquatic plants. Places such as swamps marshes, meadows, lakes, and other such places are among some of the favorite nesting areas. Canadian and Alaskan shorelines have tundra that provides an adequate nesting site. Branta canadensis are seen nesting on small islands that don't have very tall grasses or in Muskrat houses (which are similar to small islands).
Nests are very simple and are made quickly. Materials that are used are weeds, twigs, grass, moss, needles, and other such materials. After some collection and building, she rounds out a curve or depression with her body. She drops the materials around her and moves the items to get the best fit. From time to time she rounds out the center with her chest or feet. If there are no items of vegetation the nest may only be a depression in the ground shaped by her chest and feet. Once the eggs are laid, the nest is lined with feathers and down. Down insulates against extreme warmth as well as cold, stabilizing egg temperature.
(Van Wormer, 1968)
Biomes: tundra, temperate coastal, freshwater lake
http://animaldiversity.ummz.umich.edu/accounts/branta/b._canadensis$narrative.html