Emperor goose (Chen canagica)
| Synonyms: | Anser canagica |
|---|---|
| Spanish: | Ansar Emperador |
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Aves |
| Order | Anseriformes |
| Family | Anatidae |
| Genus | Chen (1) |
| Size | Length: 66 - 89 cm (2) |
| Weight | 2.7 - 3.2 kg (2) |
The emperor goose is classified as Near Threatened (NT) on the IUCN Red List (1).
One of the rarest geese in North America (3), the emperor goose (Chen canagica) is a small, stocky goose that has dark bluish-grey plumage with black barring on the upperparts (2) (4). The legs and feet of the emperor goose are yellow-orange in colour and the bill is pink. The head and hindneck are striking white, but are often stained an orange-red colour from feeding in tidal ponds where iron oxide is present in sufficient concentration. Juvenile emperor geese have a slightly duller appearance than the adults, with brown barring on the upperparts, grey mottling on the head and foreneck, a black bill and olive-brown legs (2).
The range of the emperor goose centres on the Bering Sea in the North Pacific Ocean. It breeds in Arctic and sub-Arctic Alaska and along the north-eastern coast of Russia. The majority of the population spends winter along the coasts of the Aleutian Islands, but it may also winter in Canada and the Alaskan Peninsula (5). Occasionally, individuals have been recorded as far south as California and Japan (2).
The emperor goose inhabits open sites in the arctic tundra during the breeding season, either near costal lagoons, inland lakes or freshwater pools (2). In winter, it is mainly found along ice-free coasts (5).
The emperor goose feeds on grasses, berries and sedge leaves while at its inland breeding grounds, but feeds on algae, seaweeds, clams and mussels while on the coast during winter (2) (6), when it can be seen foraging in shallow water or on mudflats exposed by the retreating tide (6).
During the breeding season, the female emperor goose selects a nest site (4), situated on a small island in a pond or along the shoreline, where there is low, dead vegetation and good visibility (6). One to eight eggs are laid in a shallow depression in the ground lined with down, feathers and dead vegetation (2). While the female builds the nest and lays the eggs the male stays nearby and chases any intruders away (4), and confronts predators with an aggressive posture and threatening cries (2). The female is solely responsible for incubating the eggs, which hatch after 24 to 25 days (2). The chicks are capable of walking and swimming within hours after hatching and usually leave the nest in the first day, and fledge at 50 to 60 days of age (6). The emperor goose reaches sexual maturity at about three years of age (2).
In 2003 it was estimated that the Alaskan population of emperor geese was 84,500, which is a significant decrease on the 139,000 birds that were recorded in 1964 (5). The factors affecting this population decline are not well known but subsistence hunting over the years and oil spills are thought to have contributed (5). In the future, the emperor goose is likely to be impacted by climate change and the resulting alterations to its habitat. It has been predicted that 54 percent of the emperor goose’s habitat could be lost by 2070 (5).
In Alaska, the Yukon Delta Goose Management Plan provides voluntary restrictions on emperor goose subsistence hunting levels, although the extent to which people comply with the plan is not known (3). In addition, the Pacific Flyway Management Plan calls for the closure of all hunting of the emperor goose when the population falls below a three-year running average of 60,000, although closure has apparently not yet been enforceable (3) (7). A number of additional conservation measures have been recommended, including strengthening regulations to prevent oil pollution and tackling the causes of projected climate change through international agreements (4), both of which are measures that will also benefit numerous other species.
To learn more about the conservation of the emperor goose and other birds see:
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BirdLife International:
http://www.birdlife.org/ -
National Audubon Society:
http://audubon2.org/watchlist/viewSpecies.jsp?id=79
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk
- Algae: simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.
- Incubating: keeping eggs warm so that development is possible.
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IUCN Red List (October, 2010)
http://www.iucnredlist.org/ - del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
- Wells, J.V. (2007) Birder’s Conservation Handbook. Princeton University Press, Princeton, New Jersey.
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National Audubon Society (October, 2010)
http://audubon2.org/watchlist/viewSpecies.jsp?id=79 -
Birdlife International (October, 2010)
http://www.birdlife.org/ - Kaufman, K. (1996) Lives of North American Birds. Houghton Mifflin, New York.
- Pacific Flyway Council (2006) Pacific Flyway Management Plan for the Emperor Goose. Emperor Goose Subcommittee, Pacific Flyway Study Committee, Portland.