カナダガモ

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Northwest forms of the Canada goose, such as minima and leucopareia, are half the size of larger subspecies and resemble the greylag goose, having a short neck and small bill.
In the past, the Canada goose nested on the Kuril and Commander Islands, but was eradicated there. It was also successfully introduced to the United Kingdom, Northwest Europe, and New Zealand.

年齢

Canadian Geese typically live from 10 to 24 years, with a maximum recorded lifespan of 33 years and 3 months, and a theoretical lifespan ranging from 29 years and 6 months to 42 years and 2 months; the age at which they reach sexual maturity varies from 5 months and 3 weeks to 3 years. The gosling’s eyes open at birth, and the embryo develops within an egg. The "gosling" stage, characterized by downy plumage and following parents to water, lasts from 1 day to 2 months and 1 week. Following this, the "young bird after rapid growth" stage sees the young learning to fly and forage for food, lasting from 2 months and 1 week to 2 years. The “adult” stage, when the species is ready to reproduce and undertake long migrations, lasts from 2 to 20 years.

表現型

Canada Geeses have distinctive appearances at different stages of development; a gosling’s bill is short for grasping grass, and its downy feathers are a soft yellow-brown to retain body heat, while its feet with webbing aid in swimming. The young experience rapid growth, and their plumage gradually changes from down to grey-brown feathers. An adult canada goose possesses a strong black bill for cutting plants, and its body feathers are grey-brown, providing camouflage in vegetation. The adult’s head and neck are black with bright white cheeks, which help individuals recognize each other. Adult feet and webbed feet are black, facilitating both walking and swimming, and the species has long wings that enable flight over considerable distances.

生理学

The Canadian goose is a bird species with body length varying from 70 cm to 1.1 m, and weight ranging from 1.21 to 1.31 kg; wingspan reaches from 1.01 to 1.69 m. Body mass at the "Embryo" stage is in the range of 140 to 190 g. At the "Chick" stage, body weight is from 80 g to 1.8 kg, and body length is from 15 to 45 cm. During the period of "Post-Rapid Growth Juvenile," the species has a body weight from 1.8 to 4.5 kg and a body length from 50 cm to 0.9 m. An adult male or female Canadian goose is characterized by a body weight from 3.5 to 9 kg and a body length from 75 cm to 1.1 m.

生息地

Canadian Geeses inhabit temperate mixed forests with warm summers and abundant oak, birch, and maple trees, as well as temperate coniferous forests characterized by cool temperatures and snow in winter; they also occupy flooded meadows where water frequently covers the ground, shallow waters along shorelines where water levels fluctuate and crabs reside, taiga environments with cold winters and spruce and pine trees, and freshwater lakes and ponds, marshes, swamps, land, and terrestrial forests. The species thrives in climates that include very hot summers exceeding 25 to 30 degrees Celsius, consistently wet conditions with frequent rain, rainy and cool summers with winter snow, rainy and warm summers with winter snow, and winters with abundant snow and cold temperatures; they are found at elevations up to 2.5 kilometers above sea level.

隠れ家

Canadian Geeses are found on the ground near water or on small islands; the species builds or utilizes a nest structure for laying eggs and raising young. The nest is constructed from grass, twigs, and down.

地理

Canada geese inhabit the Nearctic biogeographical realm, freshwater realm, Palearctic realm, and marine realm; the species occupies ecosystems including the Piedmont Appalachian forests, Canadian aspen parklands, low-lying forests of Eastern Great Lakes, low-lying forests of the St. Lawrence Bay, low-lying forests of the Mississippi River, and mixed mesophytic forests of the Appalachians.

餌

The Canadian goose feeds exclusively on plants, nibbling grass on banks and fields and collecting algae and grains, using a pecking and shearing method to obtain food. The species' diet includes grass, aquatic plants, cereals, seeds, leaves, algae, coniferous cones, grain, and plant matter, with a daily food requirement ranging from 400 g to 1.2 kg. Canadian goose chicks feed on invertebrates such as beetles, diptera, hymenoptera, butterflies, amphipods, ribbon worms, polychetes, and oligochetes. Food is sought and obtained through grazing, but the species is threatened by golden eagles.

繁殖

The female canada goose lays eggs in a ground nest, and pairs live together for many years; embryonic development takes 3 weeks and 5 days. The size of a clutch is 4 to 7 goslings, and the female has from 4 to 7 offspring. Both parents guard the nest and lead the young to water. The species reaches maturity from 2 to 3 years of age, and reproduction occurs every 1 year.