Ross's goose (Chen rossii)
|Size||Male body length: 53 - 66 cm (2) (3)|
Wingspan: 115 - 130 cm (3)
Male weight: 1,224 - 1,880 g (2)
Female weight: 1,270 - 1,660 g (2)
- The male Ross’s goose has wart-like swellings at the base of the bill, which are thought to be a status symbol.
- There is a very rare blue morph of Ross’s goose, which was only confirmed in 1971.
- Ross’s goose and the larger snow goose hybridise and create fertile offspring.
- Ross’s goose hatchlings are able to leave the nest after just 24 hours, and are able to feed themselves and swim.
Ross's goose is classified as Least Concern (LC) on the IUCN Red List (1).
Ross’s goose (Chen rossii) is a very small (4), all-white goose, with black tips to its wings (3) (4). The short, delicate bill is black-pink at the base, becoming brighter pink (3) towards the rounded tip (5). The male has small, wart-like growths on the base of its bill, which become more prominent as it ages (5). The distinctive legs are pink and the eyes are dark (2) (3).
The female Ross’s goose is around six percent smaller than the male (5), with very few wart-like growths on the base of its bill, a shorter neck and a flatter forehead. The juvenile is brown-grey on the head, back and breast, with darker flight feathers (2). The bill and feet are grey in the juvenile, gaining their pink colouration as the individual ages (4).
Ross’s goose has a rare blue colour morph, whose existence was not confirmed until as recently as 1971 (2).
The call of Ross’s goose is a sad, murmuring ‘mmmmm’ or ‘uuuhhhh’, which is used for contact, especially when groups are in danger (2).
The breeding range of Ross’s goose spreads throughout the Canadian Arctic. In winter, flocks mostly migrate to California, although congregations can also be found in Texas and northern Mexico (2) (3) (4) (5) (6). The range of this species is thought to be spreading east (4). There have been reports of vagrant Ross’s geese in the Netherlands (2) (6).
During the breeding season Ross’s goose is found in Arctic tundra (2) (3) (5), where it nests in open areas and on islands in shallow lakes (4). In winter, large aggregations are found in agricultural fields and shallow wetlands (2) (4) (5), using nearby reservoirs and lakes to roost (2).
Ross’s goose has an herbivorous diet, which consists of roots, leaves, stems, sedges, legumes and domestic grains (2) (4) (5). This species can be seen foraging on the ground individually, or may form larger groups (5).
A migratory species, Ross’s goose leaves its breeding ground in mid-October and arrives in its overwintering range in late October. Flocks begin to return to the breeding grounds in early March. While migrating, this species is highly gregarious and forms large flocks (5).
Between late May and June mated pairs arrive at the breeding grounds and immediately establish a nesting territory. Although Ross’s goose is thought to be monogamous, copulation with other individuals outside of the pair is also known to occur (2). The female builds the nest during and after the territory establishment (5). The nest is a shallow structure, with twigs, grass, moss and lichens in the outer layer and mostly down on the inner layer (2). The female lays an average clutch of between 4 and 5 eggs (2) at the beginning of June (5), which are laid at 36-hour intervals (2). The female incubates the eggs, while being guarded by the male (4), and the eggs hatch between late June and July (5). If the female leaves the nest, it will cover the eggs with a layer of down to keep the eggs warm and hide them from predators (4). The young are able to leave the nest 24 hours after hatching, and can swim and feed themselves (4) (5). For up to a year after birth, the young maintain an association with the adults (5) and may remain with them until the next breeding season. Ross’s goose reaches sexual maturity after 2 or 3 years, and lives for up to 14 years in the wild (2).
Historically, Ross’s goose was threatened by hunting in its winter range, and this market drastically reduced wild populations and may have threatened this species with extinction. Hunting became illegal in 1931 and the population has dramatically increased since (5), causing North American authorities to change the law and allow hunting to resume, with the aim of reducing the population size by half (2).
As it is such an abundant species, there do not seem to be many threats to the future survival of Ross’s goose, although habitat loss, disease (5) and hybridisation with the snow goose (Chen caerulescens) may affect population numbers in the future (2) (4).
The breeding range of Ross’s goose has been made a Federal Migratory Bird Sanctuary, which offers it a small amount of protection (5), although there are not currently known to be any other conservation measures in place for this abundant species.
More information on Ross’s goose:
Cornell Lab of Ornithology: All About Birds - Ross’s goose:
More information on bird conservation:
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- Flight feathers: the feathers at the end of the wing, involved in flight.
- Herbivorous: having a diet that comprises only vegetable matter.
- Hybridisation: cross-breeding between two different species or subspecies.
- Incubate: to keep eggs warm so that development is possible.
- Legume: a plant in the legume family (Leguminosae or Fabaceae), which includes peas, beans, clover and alfalfa. Leguminous plants produce seeds in pods (legumes), and typically have root nodules containing symbiotic bacteria which are able to convert nitrogen from the air into nitrogen-containing compounds that benefit the plant.
- Monogamous: having only one mate during a breeding season, or throughout the breeding life of a pair.
- Morph: one of two or more distinct types of a given species, often distinct colour forms, which occur in the same population at the same time (that is, are not geographical or seasonal variations).
- Territory: an area occupied and defended by an animal, a pair of animals or a group.
- Tundra: treeless, grassy plains characteristic of Arctic and sub-Arctic regions. They are very cold and have little rainfall.
- Vagrant: an individual found outside the normal range of the species.
IUCN Red List (November, 2013)
del Hoyo, J. and Carboneras, C. (1992) Handbook of the Birds of the World. Volume 1:Ostrich to Ducks. Lynx Edicions, Barcelona. Available at:
- Brazil, M. (2009) Birds of East Asia. Christopher Helm Publishers, London.
Cornell Lab of Ornithology: All About Birds - Ross’s goose (November, 2013)
Ryder, J.P. and Alisauskas, R.T. (2013) Ross’s goose (Chen rossii). In: Poole, A. (Ed.) Birds of North America Online. Cornell Lab of Ornithology, Ithaca. Available at:
BirdLife International (November, 2013)