Canada goose |
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History and biology: The Canada goose is the large goose commonly seen in suburban and farming areas. Once near extinction in the 1800s, due to unregulated market hunting, the Canada goose has responded well to wetlands preservation, wildlife refuges, and restocking projects conducted by wildlife agencies. The species has come back in such numbers and population densities that it is now causing problems for humans. A Canada goose is a plump, sturdy bird with a long neck, short wings, and short legs. It can easily walk on land because its legs are set more forward under its breast than with other waterfowl. The feet are webbed between the three front toes. Both sexes look alike except for size. The adult male is about three feet long and weighs about 9 pounds, while the female is smaller. The bill, head, neck, legs, feet, and tail are black: there is a broad, white "chinstrap" marking on the throat and cheeks; and the upper body is a mottled brownish gray. There is a thick down under the feathers as insulation for protection from cold weather. Its migratory habits have changed with its adaptation to human related changes in the environment. Once it was a migratory species but now it over winters wherever there is a plentiful supply of food, often associated with human agricultural activities. The Canada goose diet consists almost exclusively of plants. It eats roots, stems, shoots, and seeds both in water and on land. In water, the Canada goose will tip forward, submerge its head, and pull up aquatic vegetation with its rounded beak. It will eat wigeon grass, eelgrass, pondweed, spike rush, American bulrush, cordgrass, glasswort, and algae. On land, a goose will graze on grasses, turf, and clover, and it will clean up grain, such as wheat, millet, corn, barely, rye, and rice, that is not harvested by farm equipment. It will also invade and feed on cultivated crops, whereupon it becomes a pest, such as rice, turf, soybeans, and wheat. The young will feed on crustaceans, insects, and snails. Feeding is generally twice a day for 2 or 3 hours in the morning and again in the afternoon. A Canada goose will fly up to 20 miles from its aquatic resting refuge to feed. At least one sentinel in a flock of geese will always have its head up and be alert for danger. A Canada goose is quite vocal. In flight, it makes a honking sound, when feeding, it makes a gabbling sound, and when angry, it hisses. A pair of geese will breed at 2 to 3 years of age in early spring, usually among the first waterfowl to breed. A pair mates for life. If one of them dies, the other finds a new mate. Nesting is done in open view such as islands in rivers and lakes, the tops of muskrat and beaver houses in marshes, rocky cliffs, and grassy fields near water. The male stands guard while the female selects a site and builds the nest. The nest is made of sticks lined with down in a depression in the soil. The female will lay 4 to 10 eggs (average 5 or six). The female incubates while the gander protects her, the nest, and a 5 acre territory. Incubation takes an average of 28 days. Gooslings are precocial; their eyes open, covered with fuzz, and they can walk and swim after hatching. The family abandons the nest within one day. Both parents stay with the young. The female broods the goslings at night for about one week. About 70% of nests are successful in rearing young. The remaining 30% succumb to predation by possums, skunks, raccoons, and abandonment by parents. Gosling fall prey to foxes, coyotes, hawks, owls, and snapping turtles. Molting begins when the young are about half grown. After adults loose their feathers, the parents and young grow feathers at about the same time so they are all able to fly together. As the days shorten, families aggregate into large flocks in preparation for migration. As a migratory species, a Canada goose is protected by the United States Fish and Wildlife Service. Public Health Damage: Canada geese and their droppings create a serious and constant health problem. They may be a reservoir for the transmission of diseases to humans (zoonotic diseases) such as ornithosis, salmonellosis, several forms of encephalitis (West Nile Virus), histoplasmosis, cryptococcosis, toxoplasmosis, and coccidiosis. Canada geese are also a concern to farmers because they may carry and transmit many diseases, such as hog cholera, for livestock. In additional to the numerous infectious zoonotic diseases, geese also harbor and transmit a number of ectoparasites associated with the bird and its nests such as lice, mites, fleas, ticks, and bugs. Structural Damage: Geese feed in large flocks thereby defacing grounds and parking lots of office buildings with excretory droppings. They also cause damage to agricultural barn yards and silage areas. They foul areas where people may walk and/or work. They can damage landscape turf and ponds. Agricultural Damage: Canada geese threaten the health of livestock in United States agriculture because they may be a reservoir for the potential transmission of many livestock diseases such as salmonella and hog cholera, especially around concentrated poultry and swine production facilities. They also do damage through the consumption and contamination of agricultural seed, grain, and turf products in the field, storage facilities, and wholesale and retail outlets. Environmental Damage: Because of their commensal relationship with humans and their potential for producing large flocks, geese are a serious and constant public health and property damage problem. Economic Damage: Economic damage from geesse is difficult to assess when you consider the intangible costs of the impact of zoonotic diseases on the public health of humans, livestock, and wildlife. Additionally, it is also difficult to determine the real cost of architectural and structural damages from defacement, landscape loss and accidents by the prolific feeding activities on and in anthropogenic landscapes and parks. Also there is a significant cost to American consumers and business from the consumption and contamination of turf, seed, grain, and crops damaged by geese. References: Coded Federal Registry, 50CFR17.Subpart D, Endangered and Threatened Wildlife and Plants Coded Federal Registry, 50CFR 20.43, Wildlife and Fisheries, Hunting and Migratory Bird Regulations Coded Federal Registry, 50 CFR 21.43 Subpart D, Control of Depredating Birds Fergus, C., 2000, Wildlife of Pennsylvania and the Northeast, Stackpole Books, Mechanicsburg , PA 17055 Mallis, A. 1997. Handbook of Pest Control: The behavior, Life History, and Control of Household Pests, Eighth Edition. Mallis Handbook and Technical Training Company. Oklahoma Wildlife Conservation Commission, 2004-2005, Oklahoma Hunting Guide, Protected Species. Page 9. Oklahoma Department of Wildlife Conservation, P.O. Box 53465 , Oklahoma City , OK 73152 . Sibley, D.A., 2001, The Sibley Guide to Bird Life and Behavior, National Audubon Society, Alfred A Knopf, N.Y. Texas Parks and Wildlife Department, 2004, Hunting and Fishing Regulations, Endangered, Threatened, and Other Protected Nongame Species, Protected and Unprotected Birds, Texas Parks and wildlife, 4200 Smith School Road, Austin, Texas 78744. Wernert, S. J., 1982. North American Wildlife, The Reader's Digest Association, Inc. Pleasantville , N.Y. |
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