The Canada goose ( Branta canadensis) is a large species of goose with a black head and neck, white cheeks, white under its chin, and a brown body. It is native to the arctic and of North America, and it is occasionally found during bird migration across the Atlantic in northern Europe. It has been introduced to France, the United Kingdom, Ireland, Scandinavia, New Zealand, Japan, Chile, Argentina, and the Falkland Islands. Like most geese, the Canada goose is primarily herbivorous and normally migratory; often found on or close to fresh water, the Canada goose is also common in Brackish water marshes, estuaries, and lagoons.
Extremely adept at urban wildlife, Canada geese have established breeding colonies in urban and cultivated habitats, which provide food and few natural predators. The success of this common park species has led to it often being considered a pest species because of its excrement, its depredation of crops, its noise, its aggressive territorial behavior toward both humans and other animals, and its habit of stalking and begging for food, the latter a result of humans disobeying artificial feeding policies toward wild animals.
Branta was a Latinized form of Old Norse Brandgás, "burnt (black) goose" and the specific epithet canadensis is a Neo-Latin word meaning "from Canada". According to the Oxford English Dictionary, the first citation for the 'Canada goose' dates back to 1772. The Canada goose is also colloquially referred to as the "Canadian goose". This name may annoy some Birdwatching.
The cackling goose was originally considered to be the same species or several subspecies of the Canada goose, but in July 2004, the American Ornithologists' Union's Committee on Classification and Nomenclature split them into two species, making the cackling goose into a full species with the scientific name Branta hutchinsii. The British Ornithologists' Union followed suit in June 2005.
The AOU has divided the many subspecies between the two species. The subspecies of the Canada goose were listed as:
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 geese" were believed to be a partly hybrid population, with the birds named B. c. taverneri considered a mixture of B. c. minima, B. c. occidentalis, and B. c. parvipes. The holotype specimen of taverneri is a straightforward large pale cackling goose however, and hence the taxon is still valid today and was renamed "Taverner's cackling goose".
In addition, the barnacle goose ( B. leucopsis) was determined to be a derivative of the cackling goose lineage, whereas the Hawaiian goose ( B. sandvicensis) originated from ancestral Canada geese. Thus, the species' distinctness is well evidenced. Ornithologist Harold C. Hanson, who had rediscovered wild populations of the Giant Canada Goose, proposed splitting Canada and cackling goose into six species and 200 subspecies.
The seven subspecies of this bird vary widely in size and plumage details, but all are recognizable as Canada geese. Some of the smaller races can be hard to distinguish from the cackling goose, which slightly overlap in mass. However, most subspecies of the cackling goose (exclusive of Richardson's cackling goose, B. h. hutchinsii) are considerably smaller. The smallest cackling goose, B. h. minima, is scarcely larger than a mallard. In addition to the size difference, cackling geese also have a shorter neck and smaller bill, which can be useful when small Canada geese comingle with relatively large cackling geese. Of the "true geese" (i.e., the genera Anser and Branta), the Canada goose is on average the largest living species, although some other species that are geese in name, if not of close relation to these genera, are on average heavier, such as the spur-winged goose and Cape Barren goose.
Canada geese range from in length and have a wingspan.
The male Canada goose usually weighs , averaging amongst all subspecies . The female looks virtually identical, but is slightly lighter at , averaging amongst all subspecies , and generally 10% smaller in linear dimensions than the male counterparts.Mowbray, Thomas B., Craig R. Ely, James S. Sedinger and Robert E. Trost. (2002). "Canada Goose ( Branta canadensis)", The Birds of North America Online (A. Poole, ed.). Ithaca: Cornell Lab of Ornithology The honk refers to the call of the male Canada goose, while the call refers to the female goose. The calls are similar, however, the is shorter and more high-pitched than the honk of males. When agitated or aggressively defending territory, Canada geese will typically initiate an encounter with a high-pitched hiss. Canada geese communicate with ten different vocalizations, each in response to a different situation confronting them.
By the early 20th century, overhunting and loss of habitat in the late 19th and early 20th centuries 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.
In 1964, the Northern Prairie Wildlife Research Center was built near Jamestown, North Dakota. Its first director, Harvey K. Nelson, talked Forrest Lee into leaving Minnesota to head the center's Canada goose production and restoration program. Forrest soon had 64 pens with 64 breeding pairs of screened, high-quality birds. The project involved private, state, and federal resources and relied on the expertise and cooperation of many individuals. By the end of 1981, more than 6,000 giant Canada geese had been released at 83 sites in 26 counties in North Dakota.
In recent years, Canada goose populations in some areas have grown substantially, so much so that many consider them pests for their droppings, bacteria in their droppings, noise, and confrontational behavior. This problem is partially due to the removal of natural Predation and an abundance of safe, human-made bodies of water near food sources, such as those found on golf courses, in public parks and beaches, on sports fields, and in planned communities. Due in part to the interbreeding of various migratory subspecies with the introduced non-migratory giant subspecies, Canada geese are frequently a year-round feature of such urban environments.
Contrary to its normal migration routine, large flocks of Canada geese have established permanent residence along the Pacific coast of North America from British Columbia's Lower Mainland and Vancouver Island area south to the San Francisco Bay area of Northern California. There are also resident Atlantic coast populations, such as on Chesapeake Bay, 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 in apartment complexes. In 2015, the Ohio population of Canada geese was reported as roughly 130,000, with the number likely to continue increasing. Many of the geese, previously migratory, reportedly had become native, remaining in the state even in the summer. The increase was attributed to a lack of natural predators, an abundance of water, and plentiful grass in manicured lawns in urban areas.
Canada geese were eliminated in Ohio following the American Civil War but were reintroduced in 1956 with 10 pairs. The population was estimated at 18,000 in 1979. The geese are considered protected, though a hunting season is allowed from September 1–15, with a daily bag limit of five. The Ohio Department of Natural Resources recommends several non-lethal scare and hazing tactics for nuisance geese, but if such methods have been used without success, they may issue a permit which can be used from March 11 through August 31 to destroy nests, conduct a goose roundup or exterminate geese.
Canada geese were also introduced in Europe in the early 17th century by explorer Samuel de Champlain who sent several pairs of geese to France as a present for King Louis XIII. The geese were first introduced in Great Britain in the late 17th century as an addition to King James II's waterfowl collection in St. James's Park. By the middle of the 18th century, Canada geese had established populations in France and Great Britain,Attenborough, D. 1998. The Life of Birds. p.299 BBC. but also in Ireland. They were also introduced in the Netherlands, Belgium, Germany, Scandinavia, and Finland in the 20th Century, starting in Sweden in 1929. Most European populations are not migratory, but those in more northerly parts of Sweden and Finland migrate to the North Sea and Baltic Sea coasts.
Semi-tame Feral animal birds are common in parks, and have become a pest in some areas. In Great Britain, Canada geese were originally introduced as a decorative and game bird in the 17th century on numerous country estates, but remained uncommon until the mid-20th century. In 1953, the population in the British Isles was estimated between 2,670-3,482 by the British Trust for Ornithology and at a minimum of 10,090 by the Wildfowl Trust. At this time, colonies occurred mainly in the parks and lakes of individual estates; over the 1970s, however, the geese began to spread into bodies of water and wetlands throughout the countryside. Their population grew to an estimated 60-64,000 in 1990 and 82,000 in 1999, as changing agricultural practices and urban growth provided new habitat, with an estimated 165,000 wintering individuals in 2017. An attempt to translocate breeding pairs away from agricultural zones in the 50s and 60s backfired, causing establishment of new subpopulations and an overall population explosion. The British populations are most concentrated in South East England and the Midlands, but have spread from there into moorlands, upland waters, and human-occupied areas. The species' spread and naturalization are due to the lack of competing animals in its ecological niche as a large aquatic bird that favors parks and open woodlands, as the only significant competitor to it is the mute swan, alongside the creation of favorable breeding areas through the establishment of reservoirs and flooded gravel pits and the introduced populations losing their instinct to migrate.
Ecologically, Canada geese have been observed to drive away native ducks and swans from nesting areas due to the press of their greater numbers, and to overgraze the shoots and rhizomes of aquatic plants. Their droppings also contribute to eutrophication in water. They are also considered to be a potential agricultural and park pest due to their heavy grazing of vegetation. While adult birds lack predators outside of humans, goslings and eggs are taken by European mink, Eurasian otter, and mute swans.
European birds are mostly descended from the nominate subspecies B. c. canadensis, likely with some contributions from the subspecies B. c. maxima.
Males exhibit agonistic behavior both on and off breeding and nesting grounds. This behavior rarely involves interspecific killing. One documented case involved a male defending his nest from a Brant goose that wandered into the area; the following attack lasted for one hour until the death of the brant. The cause of death was suffocation or drowning in mud as a direct result of the Canada goose's pecking the head of the brant into the mud. Researchers attributed it to high hormone levels and the brant's inability to leave the nesting area.
In urban areas, it is also known to pick food out of garbage bins. They are also sometimes hand-fed a variety of grains and other foods by humans in parks. Canada geese prefer lawn grass in urban areas. They usually graze in open areas with wide clearance to avoid potential predators.
Its nest is usually located in an elevated area near water such as streams, lakes, ponds, and sometimes on a American beaver lodge. Its eggs are laid in a shallow depression lined with plant material and down.
The incubation period, in which the female incubates while the male remains nearby, lasts for 24–32 days after laying. Canada geese can respond to external climatic factors by adjusting their laying date to spring maximum temperatures, which may benefit their nesting success. As the annual summer molt also takes place during the breeding season, the adults lose their for 20–40 days, regaining flight about the same time as their goslings start to fly.
As soon as the goslings hatch, they are immediately capable of walking, swimming, and finding their own food (a diet similar to that of adult geese). Parents are often seen leading their goslings in a line, usually with one adult 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 who approach: first giving a warning hiss, and then attacking with bites and slaps of the wings. Although parents are hostile to unfamiliar geese, they may form groups of a number of goslings and a few adults, called crèches.
The offspring enter the Fledge stage any time from six to nine weeks of age. They do not leave their parents until after the spring migration, when they return to their birthplace.
Canada geese fly in a distinctive V-shaped flight formation, with an altitude of 1 km (3,000 feet) for migration flight. The maximum flight ceiling of Canada geese is unknown, but they have been reported at 9 km (29,000 feet).
Flying in the V formation has been the subject of study by researchers. 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 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 lowering the temperature at which the muscles work. Also, other studies show levels of stress hormones such as corticosterone rise dramatically in these birds during and after a migration.
Once they reach adulthood, due to their large size and often aggressive behavior, Canada geese are rarely preyed on, although prior injury may make them more vulnerable to natural predators.Sargeant, A. B. and D. G. Raveling. (1992) "Mortality during the breeding season", pp. 396–422 in Ecology and management of breeding waterfowl. Batt, B. D. J., A. D. Afton, M. G. Anderson, C. D. Ankney, D. H. Johnson, et al. (eds.) Univ. of Minnesota Press, Minneapolis. Beyond humans, adults can be taken by coyotes and Wolf ( Canis lupus).Raveling, D. G. and H. G. Lumsden. (1977). "Nesting ecology of Canada Geese in the Hudson Bay Lowlands of Ontario: Evolution and population regulation". Fish Wildl. Res. Rep. No. 98. Ontario Min. Nat. Resour. Avian predators that are known to kill adults, as well as young geese, include ( Bubo scandiacus), ( Aquila chrysaetos) and ( Haliaeetus leucocephalus) and, though rarely on large adult geese, great horned owls ( Bubo virginianus), ( Accipiter gentilis),Veldkamp R. (2008). Cormorants. De Takkeling 16: 85–91.Madsen, J. (1988). Goshawk, Accipiter gentilis, harassing and killing brent geese Branta bernicla. Meddelelse fra Vildtbiologisk Station (Denmark). ( Falco peregrinus), and ( Falco rusticolus).
Adult geese are quite vigorous at displacing potential predators from the nest site, with predator prevention usually falling to the larger male of the pair.Bent, A. C. (1925). Life histories of North American wild fowl, Pt. 2. U.S. Natl. Mus. Bull. 130.Palmer, R. S. (1976). Handbook of North American birds, Vol. 2: Waterfowl. Pt. 1. Yale Univ. Press, New Haven, CT. Males usually attempt to draw attention of approaching predators and toll (mob terrestrial predators without physical contact) often in accompaniment with males of other goose species. Eagles frequently cause geese to fly off en masse from some distance, though in other instances, geese may seem unconcerned at perched bald eagles nearby, seemingly only reacting if the eagle is displaying active hunting behavior. Canada geese are quite wary of humans where they are regularly hunted and killed, but can otherwise become habituated to fearlessness toward humans, especially where they are fed by them. This often leads to the geese becoming overly aggressive toward humans, and large groups of the birds may be considered a nuisance if they are causing persistent problems to humans and other animals in the surrounding area.
In North America, nonmigratory 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 one of the most common waterfowl species in North America. In many areas, nonmigratory 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. State Parks Again Offering Early Canada Goose Hunting. Pennsylvania Department of Conservation and Natural Resources (August 26, 2011) An extended hunting season, deploying noise makers, and hazing by dogs have been used in an attempt to disrupt suspect flocks. A goal of conservationists has been to focus hunting on the nonmigratory populations (which tend to be larger and more of a nuisance) as opposed to migratory flocks showing natural behavior, which may be rarer.
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, which find the geese obtrusive or object to their waste. Board of Park Commissioners (Seattle) Meeting Minutes . July 12, 2001 Addling goose eggs and destroying nests are promoted as humane population control methods. Flocks of Canada geese can also be captured during molt and this method of culling is used to control invasive populations.
Canada geese are protected from hunting and capture outside of designated hunting seasons in the United States by the Migratory Bird Treaty Act, and in Canada under the Migratory Birds Convention Act. Frequently Asked Questions – Canada Geese . Canadian Wildlife Service In both countries, commercial transactions such as buying or trading are mostly prohibited and the possession, hunting, and interfering with the activity of the animals are subject to restrictions. In the UK, as with native bird species, the nests and eggs of Canada geese are fully protected by law, except when their removal has been specifically licensed, and shooting is generally permitted only during the defined open season. Geese have a tendency to attack humans when they feel themselves or their goslings to be threatened. First, the geese stand erect, spread their wings, and produce a hissing sound. Next, the geese charge. They may then peck or attack with their wings. Goose Attacks . Division of Wildlife (Ohio)
In 1995, a U.S. Air Force E-3 Sentry aircraft at Elmendorf AFB, Alaska, struck a flock of Canada geese on takeoff, losing power in both port side engines. It crashed from the runway, killing all 24 crew members. The accident sparked efforts to avoid such events, including habitat modification, aversion tactics, herding and relocation, and culling of flocks.Barela, Timothy P. (September 22, 1995) Fowl Play. U.S. Air Force News In 2009, a collision with a flock of migratory Canada geese resulted in US Airways Flight 1549 suffering a total loss of power from both engines after takeoff, forcing the crew of the aircraft to ditch the plane in the Hudson River with no loss of human life.
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