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Branta canadensis
Canada goose


By Tanya Dewey and Heather Lutz

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Branta
Species: Branta canadensis
Members of this Species

Geographic Range

Canada Geese are found throughout North America. There are four subspecies (or populations); each is found in a different area of North America. These subspecies are the southern, northern, western and Aleutian-Canadian populations. The southern population ranges from 60 degrees north latitude to the Rockies and Atlantic Ocean. The northern population ranges north of 60 degrees north latitude in the Arctic and Subarctic. Canada geese travel to the southern parts of the United States during the winter. The western population is found along the coasts of Alaska and British Columbia. The Aleutian-Canadian population is rarely found. A general trend in all subspecies is that they they spend summers in the northern parts of North America, especially Canada, and migrate south to areas of the United States in the winter months. (Ogilvie, 1978; Owen, 1980)

Biogeographic Regions
nearctic (Native )

Habitat

Canada Geese are found near waterways in open, grassy habitats such as grasslands, chaparral, and arctic tundra. They also inhabit man-made habitats that are open and grassy, such as golf courses, agricultural land, airports, and parks.

Habitat Regions
temperate ; terrestrial ; freshwater

Terrestrial Biomes
tundra ; savanna or grassland

Aquatic Biomes
lakes and ponds; rivers and streams; coastal

Wetlands
marsh

Other Habitat Features
suburban ; agricultural ; riparian

Physical Description

Range mass
1100 to 8000 g
(38.77 to 281.94 oz)

Range length
90 to 200 cm
(35.43 to 78.74 in)

Range wingspan
127 to 173 cm
(50.00 to 68.11 in)

Branta canadensis individuals have a black neck, bill, and head with a white strap under the chin and occasional white patches elsewhere. 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. During flight the tail shows a white semi-circle just above the black tail. Females may be slightly smaller than 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. These geese have very large wings (127 to 173 cm wingspan) that can also be used as weapons. The weight of Branta canadensis varies depending on the subspecies.

Goslings (young Canada geese) are yellow with some greenish-gray colorings on top of their heads and backs. As with the adult color pattern, there is some variation among the different subspecies. Goslings of the darker subspecies have a brownish olive or blunt yellow coloring while those of the 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 that become darker as they age. (Kortright, 1942; Owen, 1980; Robbins, et al., 2001; Van Wormer, 1968)

Other Physical Features
endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism
male larger

Reproduction

Canada geese are monogamous. Pairs form during the winter, during migration or on their wintering grounds, for the next breeding season. Mated pairs may stay together for more than one year, sometimes staying together for life.

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. (Ehrlich, et al., 1988)

Mating System
monogamous

Breeding interval
Canada geese breed once yearly.

Breeding season
Females start laying eggs during the first weeks of March and continue as late as June in parts of the Arctic.

Range eggs per season
2 to 9

Average eggs per season
5

Average eggs per season
5
[External Source: AnAge]

Range time to hatching
23 to 30 days

Range fledging age
68 to 78 days

Average age at sexual or reproductive maturity (female)
1 years

Average age at sexual or reproductive maturity (male)
1 years

The average clutch size is five eggs, although this size ranges from 2 to 9 eggs. The incubation period lasts 23 to 30 days.

Females incubate the eggs, choose the location for nesting, and even build the nest without males. Males defend the territory, nest, and eggs from intruders, such as other geese. Female Canada geese pick nesting sites that are isolated but have good visibility. This allows them to readily see danger approaching and to be difficult to get at. The nesting area also must have open water with low banks so they can have access to water plants and places to get into or out of the water. Swamps, marshes, meadows, lakes, and other such areas are among some of their favorite nesting spots. The Canadian and Alaskan shorelines have expanses of tundra habitat that provide good nesting sites. Canada geese are often seen nesting on small islands that don't have very tall grasses or on 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, female geese round out a curve or depression with their bodies. They drop the materials around themselves and move the items to get the best fit. From time to time they round out the center with their chests or feet. If there are no items of vegetation the nest may only be a depression in the ground shaped by their chests 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.

Incubation must occur immediately after the last eggs are laid. The incubation period lasts 23 to 30 days. The female turns the eggs regularly to promote proper development and changes their position in the nest to maintain even incubation temperatures. 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 within 24 hours. Goslings within a clutch usually have a sex ratio of 1:1. Hatchlings fledge in 68 to 78 days after hatching. ("Canada Geese (*Branta canadensis*)", 1998; Van Wormer, 1968)

Key Reproductive Features
seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

After the eggs hatch, the family group (the offspring and parents) leave the nest and begin to travel together to feed and seek shelter. Both males and females feed and guard their young. Upon hatching, young Canada geese are able to follow their parents around and leave the nest.

Parental Investment
precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)

Lifespan/Longevity

Range lifespan
Status: wild

24 (high) years

Range lifespan
Status: captivity

42 (high) years

Average lifespan
Status: wild

364 months
[External Source: Bird Banding Laboratory]

It is not clear exactly how long the average Canada goose can live, but there have been two geese that were reported to have lived very long lives. One of them lived to be 24 years old and another reached 23. In captivity, two geese were reported to live to 42 years old. Probably most Canada geese die within their first year of life, as nestlings, fledglings, and during their first migration.

Behavior

Canada geese are highly social, being found in flocks at all times of the year except when they are nesting. Migration begins in the fall and takes place in large flocks. Large winter aggregations form while on lakes, coastal waters, and mudflats. In flight, flocks form large V's or diagonally straight lines. This is because each bird doesn't fly directly behind the others, but off to an angle. This minimizes drag on each individual bird, allowing them to take advantage of the slipstream created by the bird in front of them. They migrate at a slow pace, stopping along the way. Because of this, they arrive at their breeding grounds in good physical shape. Canada geese are active mainly during the day.

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 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.

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. These birds love to swim and bathe in the water, especially on warm days. Some subspecies have a yearly molt of flight feathers in the summer and become flightless during this time. ("Canada Geese (*Branta canadensis*)", 1998; Owen, 1980; Van Wormer, 1968)

Key Behaviors
flies; natatorial ; diurnal ; migratory ; social ; colonial

Communication and Perception

Canada geese have good eyesight, which is necessary for flight. They must move their heads in order to see all the way around themselves. 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. Canada geese have excellent hearing and the ears are located on the side of its head. Canada geese often use body movements to communicate with each other. These geese also have the ability to make at least 10 different calls

Communication Channels
visual ; tactile ; acoustic

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. ("Canada Geese (*Branta canadensis*)", 1998; Owen, 1980; Van Wormer, 1968)

Primary Diet
herbivore (Folivore )

Plant Foods
leaves; roots and tubers; seeds, grains, and nuts; algae

Predation

Known Predators


Unguarded nests and eggs are targets for predators such as gulls, common ravens, American crows, skunks, domestic dogs, and many others. Males send 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 stretch out their necks to camouflage the nest.

Canada geese are also a common game bird, hunted regularly by humans.

Ecosystem Roles

As well as dispersing the seeds of the plants they eat, Canada Geese are important prey for many predators in the ecosystems in which they live.

Ecosystem Impact
disperses seeds

Economic Importance for Humans: Positive

Canada Geese have been hunted by humans for hundreds of years. Native Americans hunted them in the spring migration. Eskimos hunted them by taking advantage of the molt that leaves them flightless. Even early white settlers took advantage of these birds and hunted them for food. These birds are still being hunted today in the United States and Canada. (Owen, 1980; Van Wormer, 1968)

Positive Impacts
food ; body parts are source of valuable material

Economic Importance for Humans: Negative

Canada geese can become a nuisance, especially when normally migratory birds become resident. They can overgraze lawns and crops, leading to erosion. On lawns, their feces can annoy humans. Build-up of fecal matter can lead to reduced water quality, by fostering bacteria and adding much nitrogen and phosphorus.

Canada geese can be an exceptional annoyance in Atlantic flyway states by crowding in on golf courses, beaches, parks, playing fields, and yards. In the eastern states, Canada Geese have been very harmful to local crops and have forced farmers to plant a lot more winter wheat to compensate for the damage done by these geese. (NJ Department of Environmental Protection, 2001)

Negative Impacts
crop pest

Conservation Status

IUCN Red List of Threatened Species [Link]
Least Concern
More Information

US Migratory Bird Act [Link]
Protected

US Federal List [Link]
Threatened

CITES [Link]
No special status

State of Michigan List [Link]
No special status

In 1918 when the Migratory Bird Treaty was passed, spring shooting was prohibited in the United States and Canada. This regulated the hunting season to three and a half months of the year. The hunting regulations currently in place are for shooting season limits and bag limits in relation to the amount of birds currently in the population. A quota system was put in place in 1960 to regulate the number of geese shot in a given year.

One subspecies, Aleutian-Canadian Geese, were listed as endangered by the U.S. Fish and Wildlife Service in 1967. This was due to the introduction of a non-native arctic fox species to their nesting islands. They became predatory on the naturally defenseless geese. This introduction caused the population to decline to approximately 800 individuals. However, in 1990, due to increasing numbers, the U.S. Fish and Wildlife Service changed the listing to threatened. The state of Alaska also changed the species listing from endangered to a species of special concern. Aleutian-Canadian Geese are now recorded around 15,000 individuals and nesting on eight islands.

On the other hand, some populations have grown so numerous, there are many organizations who are trying to regulate the populations of these geese. They see this as necessary because if the goose population continues to rise at its current rate, they will present a very serious problem to their surrounding environment in only a few years. Other organizations believe that the methods and ideas of these organizations are cruel and unnecessary. These groups believe that the growing population is not nearly as threatening as some believe and that they are actually at great risk because of the excessive hunting and death by pesticides that geese populations experience. (Owen, 1980)

Other Comments

A chemical called methiocarb is being used on grass to prevent geese from grazing on it in some areas. Methiocarb makes the geese feel sick, but thus far has not resulted in any deaths. The toxic effects of this chemical are still being researched. Over 200 geese have been killed by the chemical parathion in Texas. Golden eagles and bald eagles have been seen eating the bodies of geese that have been killed by parathion which means it could potentially be very dangerous for them as well.

For More Information

Find Branta canadensis information at

Contributors

Tanya Dewey (author, editor), Animal Diversity Web, University of Michigan Museum of Zoology.

Kari Kirschbaum (editor), Animal Diversity Web Staff.

Heather Lutz (author), University of Michigan, Phil Myers (editor), Museum of Zoology, University of Michigan.

References

1998. "Canada Geese (*Branta canadensis*)" (On-line). Accessed March 12, 2000 at http://www.rhrwildlife.com/cgee.htm.

Bruun, B. 1964. Ducks, Geese, and Swans. New York, NY: Odyssey Press.

Ehrlich, P., D. Dobkin, D. Wheye. 1988. The Birder's Handbook: A Field Guide to the Natural History of North American Birds. New York: Simon and Schuster.

Jaques, F. 1939. The Geese Fly High. Minneapolis, Minnesota: University of Minnesota Press.

Kortright, F. 1942. The Ducks, Geese and Swans of North America. Washington, DC: The American Wildlife Institute.

NJ Department of Environmental Protection, 2001. "Management of Canada geese in urban areas" (On-line). Accessed 14 May 2002 at http://www.state.nj.us/dep/watershedmgt/DOCS/BMP_DOCS/Goosedraft.pdf.

Ogilvie, M. 1978. Wild Geese. Vermillion, SD: Buteo Books.

Owen, M. 1980. Wild Geese of the World: Their Life History and Ecology. London: BT Batsford Ltd.

Robbins, C., B. Bruun, H. Zim. 2001. A guide to field identification: Birds of North America. New York: St. Martin's Press.

Van Wormer, J. 1968. The World of the Canadian Goose. Philadelphia: Lippincott.

To cite this page: Lutz, H. 2002. "Branta canadensis" (On-line), Animal Diversity Web. Accessed May 31, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Branta_canadensis.html

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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