Canada Goose

For the outerwear manufacturer, see Canada Goose (clothing).

Canada Goose
Conservation status
Least Concern (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Subfamily:	Anserinae
Tribe:	Anserini
Genus:	Branta
Species:	B. canadensis
Binomial name
Branta canadensis (Linnaeus, 1758)
Subspecies
B. c. occidentalis – Dusky Canada Goose, (Baird, 1858) B. c. fulva – Vancouver Canada Goose, (Delacour, 1951) B. c. parvipes – Lesser Canada Goose, (Cassin, 1852) B. c. moffitti – Moffitt's Canada Goose, (Aldrich, 1946) B. c. maxima – Giant Canada Goose, (Delacour, 1951) B. c. interior – Interior Canada Goose, (Todd, 1938) B. c. canadensis – Atlantic Canada Goose, (Linnaeus, 1758)
Canada Goose distribution, including native (dark tones) and introduced (light tones) populations Canada Goose summer: yellow Canada Goose all year: green Canada Goose winter: blue Cackling Goose summer: pink

The Canada Goose (Branta canadensis) is a wild goose belonging to the genus Branta, which is native to arctic and temperate regions of North America, having a black head and neck, white patches on the face, and a brownish-gray body.

Taxonomy and etymology

The Canada Goose was one of the many species described by Carl Linnaeus in his 18th-century work Systema Naturae.^[2] It belongs to the Branta genus of geese, which contains species with largely black plumage, distinguishing them from the grey species of the Anser genus. The specific epithet canadensis is a New Latin word meaning "from Canada". According to the Oxford English Dictionary, the first citation for the 'Canada Goose' dates back to 1772. The Cackling Goose was formerly considered to be a set of subspecies of the Canada Goose. The Canada Goose is also referred to as the Canadian Goose.^[3]

The Cackling Goose was originally considered to be the same species or a subspecies of the Canada Goose, but in July 2004 the American Ornithologists' Union's Committee on Classification and Nomenclature split the two into two species, making Cackling Goose into a full species with the scientific name Branta hutchinsii. The British Ornithologists' Union followed suit in June 2005.^[4]

The AOU has divided the many subspecies between the two animals. To the present species were assigned:

• Atlantic Canada Goose, Branta canadensis canadensis
• Interior Canada Goose, Branta canadensis interior
• Giant Canada Goose, Branta canadensis maxima
• Moffitt's Canada Goose, Branta canadensis moffitti
• Vancouver Canada Goose, Branta canadensis fulva
• Dusky Canada Goose, Branta canadensis occidentalis
• part of "Lesser complex", Branta canadensis parvipes

The distinctions between the two geese have led to confusion and debate among ornithologists. This has been aggravated by the overlap between the small types of Canada Goose and larger types of Cackling Goose. The old "Lesser Canada Goose" was believed to be a partly hybrid population, with the birds named taverneri considered a mixture of minima, occidentalis and parvipes. In addition, it has been determined that the Barnacle Goose is a derivative of the Cackling Goose lineage, whereas the Hawaiian Goose is an insular representative of the Canada Goose.

Description

Yellow plumage of gosling

The black head and neck with white "chinstrap" distinguish the Canada Goose from all other goose species, with the exception of the Barnacle Goose, but the latter has a black breast, and also grey, rather than brownish, body plumage.^[5] There are seven subspecies of this bird, of varying sizes and plumage details, but all are recognizable as Canada Geese. Some of the smaller races can be hard to distinguish from the newly-separated Cackling Goose.

This species ranges from 75 to 110 cm (30 to 43 in) in length and has a 127–185 cm (50–73 in) wingspan.^[6] The male usually weighs 3.2–6.5 kg (7.1–14 lb), and can be very aggressive in defending territory. The female looks virtually identical but is slightly lighter at 2.5–5.5 kg (5.5–12 lb), generally 10% smaller than its male counterpart, and has a different honk. An exceptionally large male of the race B. c. maxima, the "giant Canada goose" (which rarely exceed 8 kilograms (18 lb)), weighed 10.9 kilograms (24 lb) and had a wingspan of 2.24 metres (7.3 ft). This specimen is the largest wild goose ever recorded of any species. The life span in the wild of geese that survive to adulthood ranges 10–24 years.^[7]

Distribution and habitat

This species is native to North America. It breeds in Canada and the northern United States in a variety of habitats. Its nest is usually located in an elevated area near water such as streams, lakes, ponds and sometimes on a beaver lodge. Its eggs are laid in a shallow depression lined with plant material and down. The Great Lakes region maintains a very large population of Canada Geese.

By the early 20th century, over-hunting and loss of habitat in the late 19th century and early 20th century had resulted in a serious decline in the numbers of this bird in its native range. The Giant Canada Goose subspecies was believed to be extinct in the 1950s until, in 1962, a small flock was discovered wintering in Rochester, Minnesota, by Harold Hanson of the Illinois Natural History Survey.^[8] With improved game laws and habitat recreation and preservation programs, their populations have recovered in most of their range, although some local populations, especially of the subspecies occidentalis, may still be declining.

In recent years, Canada Geese populations in some areas have grown substantially, so much so that many consider them pests (for their droppings, the bacteria in their droppings, noise and confrontational behavior). This problem is partially due to the removal of natural predators and an abundance of safe, man-made bodies of water (such as on golf courses, public parks and beaches, and in planned communities).

Contrary to its normal migration routine, large flocks of Canada Geese have established permanent residence in the Chesapeake Bay and in Virginia's James River regions, and in the Triangle area of North Carolina (Raleigh, Durham, Chapel Hill), and nearby Hillsborough. Some Canada Geese have taken up permanent residence as far south as Florida, in places such as retention ponds in apartment complexes, etc. Some flocks in Canada may even choose not to migrate, even during the winter, if food (such as human leftovers) is constantly available throughout the season.

Outside North America

Canada Geese have reached northern Europe naturally, as has been proved by ringing recoveries. The birds are of at least the subspecies parvipes, and possibly others. Canada Geese are also found naturally on the Kamchatka Peninsula in eastern Siberia, eastern China, and throughout Japan.

Greater Canada Geese have also been introduced in Europe, and have established populations in Great Britain, the Netherlands, Belgium, Germany, and Scandinavia. Semi-tame feral birds are common in parks, and have become a pest in some areas. In the early 17th century, explorer Samuel de Champlain sent several pairs of geese to France as a present for King Louis XIII. The geese were first introduced in Britain in the late 17th century as an addition to King James II's waterfowl collection in St. James's Park.

Canada Geese were introduced as a game bird into New Zealand and have also become a problem in some areas, fouling pastures and damaging crops. They were protected under the Wildlife Act 1953 and the population was managed by Fish and Game New Zealand who culled excessive bird numbers. In 2011 the government removed the protection status allowing anyone to kill the birds.^[9] It was feared that farmers would resort to poisoning the birds although this was denied by Federated Farmers.^[10]

Behavior

In flight

Like most geese, the Canada Goose is naturally migratory with the wintering range being most of the United States. The calls overhead from large groups of Canada Geese flying in V-shaped formation signal the transitions into spring and autumn. In some areas, migration routes have changed due to changes in habitat and food sources. In mild climates from California to the Great Lakes, some of the population has become non-migratory due to adequate winter food supply and a lack of former predators.^{[citation needed]}

Diet

Canada Geese are primarily herbivores,^[11] although they sometimes eat small insects and fish.^[12] Their diet includes green vegetation and grains. The Canada Goose eats a variety of grasses when on land. It feeds by grasping a blade of grass with the bill, then tearing it with a jerk of the head. The Canada Goose also eats grains such as wheat, beans, rice, and corn when they are available. In the water, it feeds from silt at the bottom of the body of water. It also feeds on aquatic plants, such as seaweeds.^[7] In urban cities, they are also known to pick food out of garbage bins.

Reproduction

During the second year of their lives, Canada Geese find a mate. They are monogamous, and most couples stay together all of their lives.^[7] If one dies, the other may find a new mate. The female lays 3–8 eggs and both parents protect the nest while the eggs incubate, but the female spends more time at the nest than the male.^{[citation needed]}

Known egg predators include coyotes,^[13] Arctic Foxes, Northern Raccoons, Red Foxes, large gulls, Common Raven, American Crows and bears.^[14]

The incubation period, in which the female incubates while the male remains nearby, lasts for 24–28 days after laying. As the annual summer molt also takes place during the breeding season, the adults lose their flight feathers for 20–40 days, regaining flight at about the same time as their goslings start to fly.^[15]

Adult geese are often seen leading their goslings in a line, usually with one parent at the front, and the other at the back. While protecting their goslings, parents often violently chase away nearby creatures, from small blackbirds to lone humans that approach, after warning them by giving off a hissing sound and will then attack with bites and slaps of the wings if the threat does not retreat or has seized a gosling. Most of the species that prey on eggs will also take a gosling. Although parents are hostile to unfamiliar geese, they may form groups of a number of goslings and a few adults, called crèches.^{[citation needed]}

The offspring enter the fledging stage any time from 6 to 9 weeks of age. They do not leave their parents until after the spring migration, when they return to their birthplace. Once they reach adulthood, Canada Geese are rarely preyed on, but (beyond humans) can be taken by Coyotes, Red Foxes, Gray Wolves, Snowy Owls, Great Horned Owls, Golden Eagles and, most often, Bald Eagles.^[14]

Relationship with humans

USDA Wildlife Services agents trap and gas geese in Seattle, 2002

In North America, non-migratory Canada Goose populations have been on the rise. The species is frequently found on golf courses, parking lots and urban parks, which would have previously hosted only migratory geese on rare occasions. Owing to its adaptability to human-altered areas, it has become the most common waterfowl species in North America. In many areas, non-migratory Canada Geese are now regarded as pests by humans. They are suspected of being a cause of an increase in high fecal coliforms at beaches.^[16] An extended hunting season, deploying noise makers, and hazing by dogs have been used in an attempt to disrupt suspect flocks.^[17]

Since 1999, The United States Department of Agriculture Wildlife Services agency has been engaged in lethal culls of Canada Geese primarily in urban or densely populated areas. The agency responds to municipalities or private land owners, such as golf courses, who find the geese obtrusive or object to their waste.^[18] Addling goose eggs and destroying nests are promoted as humane population control methods.^[19]

In 1995, a US Air Force E-3 Sentry aircraft at Elmendorf AFB, Alaska struck a flock of Canada Geese on takeoff and crashed, killing all 24 crew. The accident sparked efforts to avoid such events, including habitat modification, aversion tactics, herding and relocation, and culling of flocks.^[20] A collision with a flock of migratory Canada Geese resulted in US Airways Flight 1549 suffering a total power loss after takeoff from LaGuardia Airport, New York City, New York on 15 January 2009. The pilot brought the plane to an emergency 'splash'-landing in the Hudson River causing only minor injuries to the 155 passengers and crew.^[21][22]

Geese have a tendency to attack humans when they feel themselves or their goslings to be threatened. First the geese will stand erect, spread their wings and produce a hissing sound. Next, the geese will charge. They may then bite or attack with their wings.^[23]

Migration

Resting in a pond during spring migration, Ottawa, Ontario

Canada geese are known for their seasonal migrations. Most Canada Geese have staging or resting areas where they join up with others. Their autumn migration can be seen from September to the beginning of November. The early migrants have a tendency to spend less time at rest stops and go through the migration a lot faster. The later birds usually spend more time at rest stops. These geese are also renowned for their V-shaped flight formation. The front position is rotated since flying in front consumes the most energy. Canada Geese leave the winter grounds more quickly than the summer grounds. Elevated thyroid hormones, such as T₃ and T₄, have been measured in geese just after a big migration. This is believed because of the long days of flying in migration the thyroid gland sends out more T₄ which will help the body cope with the longer journey. The increased T₄ levels are also associated with increased muscle mass (hypertrophy) of the breast muscle, also because of the longer time spent flying. It is believed that the body sends out more T₄ to help the goose's body with this long task by speeding up the metabolism and temperature at which the body works.^[24] Also, other studies done show corticosterone levels to rise dramatically in these birds after and during a migration. Corticosterone is known a stress hormone, so it only makes sense that when these birds are stressed by flying long distances everyday, that more corticosterone is released into their system. It is believed that a higher level of corticosterone will help the birds better manage this task.^[25]

References

1. ^ "Branta canadensis". IUCN Red List of Threatened Species. Version 2010.4. International Union for Conservation of Nature. 2009. http://www.iucnredlist.org/apps/redlist/details/141453. Retrieved 23 February 2011. 
2. ^ Linnaeus, C (1758) (in Latin). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Holmiae. (Laurentii Salvii). 
3. ^ "Canadian goose". Dictionary.com. InterActiveCorp. http://dictionary.reference.com/browse/Canadian+goose. Retrieved 3 January 2011. 
4. ^ Stackhouse, Mark. The New Goose.
5. ^ Audubon Society
6. ^ Ogilvie & Young, Wildfowl of the World. New Holland Publishers (2004), ISBN 978-1843303282
7. ^ ^{a b c} Dewey, T.; Lutz, H. (2002). "Branta canadensis". Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Branta_canadensis.html. Retrieved 2007-11-18. 
8. ^ Hanson, Harold C. (1997). The Giant Canada Goose (2nd. ed.). Southern Illinois University Press. ISBN 978-0809319244. 
9. ^ "Canada geese protection status changed". Beehive - New Zealand Government. 17 March 2011. http://beehive.govt.nz/release/canada-geese-protection-status-changed. Retrieved 24 March 2011. 
10. ^ Cronshaw, Tim (25 March 2011). "Farmers deny poison plans". The Press. 
11. ^ Mowbray, Thomas B.; Ely, Craig R.; Sedinger, James S. and Trost, Robert E. (2002). "Canada Goose (Branta canadensis)". In Poole, A.. The Birds of North America. Ithaca: Cornell Lab of Ornithology. doi:10.2173/bna.682. 
12. ^ Angus, Wilson. "Identification and range of subspecies within the Canada and Cackling Goose Complex (Branta canadensis & B. hutchinsii)". http://www.oceanwanderers.com/CAGO.Subspecies.html. 
13. ^ "Chicago Area Is Home to Growing Numbers of Coyotes". Illinois Department of Natural Resources. http://dnr.state.il.us/orc/wildlife/virtual_news/releases/070104_coyotes.htm. Retrieved 2011-04-23. 
14. ^ ^{a b} [bna.birds.cornell.edu/bna/species/682/articles/behavior|Canada Goose behavior] (2011).
15. ^ Johnsgard, Paul A. (2010) [1978]. Ducks, Geese, and Swans of the World (revised online ed.). Lincoln, Nebraska: University of Nebraska Press. p. 79. http://digitalcommons.unl.edu/biosciducksgeeseswans/5/. 
16. ^ Pennsylvania Department of Conservation and Natural Resources. Retrieved December 15, 2007, http://www.dcnr.state.pa.us/
17. ^ Woodruff, Roger A.; Green, Jeffrey S. (1995). "Livestock Herding Dogs: A Unique Application for Wildlife Damage Management". Great Plains Wildlife Damage Control Workshop Proceedings (April 10–13, Ardmore, OK: Noble Foundation) 12: 43–45 
18. ^ Board of Park Commissioners (Seattle) Meeting Minutes July 12, 2001
19. ^ Gregg MacDonald, Fairfax County Times (May 6, 2008). "Goose egg addling stirs concern in Reston". http://www.restontimes.com/news/2008/may/06/goose-egg-addling-stirs-concern-reston/. Retrieved 2009-06-10. 
20. ^ http://www.af.mil/news/airman/1297/bash.htm Air Force News article on Yukla 27
21. ^ Barbara Barrett (2009-06-08). "DNA shows jet that landed in Hudson struck migrating geese". http://www.mcclatchydc.com/homepage/story/69645.html. Retrieved 2009-06-08. 
22. ^ Maynard, Micheline (15 January 2009). "Bird Hazard Is Persistent for Planes". The New York Times. http://www.nytimes.com/2009/01/16/nyregion/16strike.html?hp. Retrieved 23 February 2010. 
23. ^ Division of Wildlife (Ohio) Goose Attacks
24. ^ T. M. John & J. C. George (1978). "Circulatory levels of thyroxine (T₄) and triiodothyronine (T₃) in the migratory Canada goose". Physiological Zoology 51 (4): 361–370. JSTOR 30160961. 
25. ^ Mėta M. Landys, John C. Wingfield & Marilyn Ramenofsky (2004). "Plasma corticosterone increases during migratory restlessness in the captive white-crowned sparrow Zonotrichia leucophrys gambelli" (PDF). Hormones and Behavior 46 (5): 574–581. doi:10.1016/j.yhbeh.2004.06.006. PMID 15555499. http://folk.uio.no/larsejo/tits/documents/Landys%20et%20al.%202004c.pdf. 

External links

• ARKive - images and movies of the Canada goose
• RSPB A to Z of UK birds
• Canada Goose at All About Birds
• Canada Goose videos, photos & sounds on the Internet Bird Collection
• BTO BirdFacts - Canada Goose