
Ross's goose (''Anser rossii''), formerly ''Chen rossii'', is a white goose with black wingtips and a relatively short neck. It is the smallest of the three
white geese that breed in North America. It is similar in appearance to a white-phase
snow goose
The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
, but about 40% smaller. Other differences from the
snow goose
The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
are that the bill is smaller in proportion to its body and lacks "black lips". Like snow geese, Ross's geese may exhibit a darker "blue" phase or morph, though this is extremely rare (<0.01% of adult birds).
Before the early 1900s, this goose was considered a rare species, possibly as a consequence of open hunting, but numbers have increased dramatically as a result of conservation measures.
It is now listed as a
species of Least Concern by the
IUCN
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
,
and is protected by the
Migratory Bird Treaty Act
The Migratory Bird Treaty Act of 1918 (MBTA), codified at (although §709 is omitted), is a United States federal law, first enacted in 1918 to implement the convention for the protection of migratory birds between the United States and Canada. ...
.
Ross's goose is named in honor of Bernard R. Ross (1827–1874), who was associated with the
Hudson's Bay Company
The Hudson's Bay Company (HBC), originally the Governor and Company of Adventurers of England Trading Into Hudson’s Bay, is a Canadian holding company of department stores, and the oldest corporation in North America. It was the owner of the ...
in Canada's
Northwest Territories
The Northwest Territories is a federal Provinces and territories of Canada, territory of Canada. At a land area of approximately and a 2021 census population of 41,070, it is the second-largest and the most populous of Provinces and territorie ...
. Members of the Hudson's Bay Company were the first Europeans to discover the arctic nesting grounds of Ross's geese in 1940.
The first recognizable description of Ross's geese, under the name "horned wavey", was given by explorer
Samuel Hearne
Samuel Hearne (February 1745 – November 1792) was an English explorer, fur-trader, author and naturalist.
He was the first European to make an overland excursion across northern Canada to the Arctic Ocean, specifically to Coronation Gulf, vi ...
eighty years before
John Cassin
John Cassin (September 6, 1813 – January 10, 1869) was an American ornithology, ornithologist from Pennsylvania. He worked as curator and vice president at the Philadelphia Academy of Natural Sciences and focused on the systemic classification ...
named it after Ross.
Description
Ross's goose have a rounded head above a short neck. The bill is short and triangular, and has a bluish base with warty structures that increase in prominence with age. Adults are identified by all-white
secondary feathers
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the Bird wing, wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those ...
, while juveniles' will be dark centered. Females average 6% smaller than males.
Legs will begin as olive gray on goslings and turn deep red as they mature.
There is no geographic variation or identified subspecies. Related species include other
''Anser'' geese, particularly the lesser
snow goose
The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
,
where the two mtDNA lineages imply frequent hybridization. Two hypotheses about the evolution of Ross's goose are that they arose from a population of snow geese that were isolated by glacial advance or in a refugium that remained ice free.
Measurements:
* Male
** Length: 23.2–25.2 in (59–64 cm)
** Weight: 42.3–55.3 oz (1198–1567 g)
** Wingspan: 44.5-45.7 in (113–116 cm)
* Female
** Length: 22.6–24.4 in (57.3–62 cm)
** Weight: 37.6–51.3 oz (1066–1454 g)
Taxonomy
Ross's geese, along with other "white geese" (i.e., snow goose,
emperor goose
The emperor goose (''Anser canagicus''), also known as the beach goose or the painted goose, is a waterfowl species in the family Anatidae, which contains the ducks, geese, and swans. In summer, the emperor goose is found in remote coastal areas ...
) previously belonged to the genus ''
Chen'', however, recent genetic sequencing has concluded that this genus was polyphyletic with the ''Anser'' genus, where most taxonomists now place Ross's goose and its allies.
Members of the ''Chen'' genus were officially transferred to ''Anser'' in the International Ornithological Committee's World Bird List version 6.3 in 2016.
Habitat
Landscape in the central
Arctic
The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...
is dominated by flat plains with some
rock outcrops and
drumlin
A drumlin, from the Irish word ("little ridge"), first recorded in 1833, in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or groun ...
s,
wet meadow
A wet meadow is a type of wetland with soils that are Solubility, saturated for part or all of the growing season which prevents the growth of trees and brush. Debate exists whether a wet meadow is a type of marsh or a completely separate type of ...
s, and marshy
tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...
. Vegetation includes patches of
dwarf birch,
willow
Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions.
Most species are known ...
, grasses, sedges, and low-growing vascular plants including
crowberry,
lapland rosebay, and
lousewort.
Large colonies of nesting birds can cause extensive damage to plants by
overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature ...
.
Behavior
Ross's geese form large nesting colonies on islands in shallow lakes and adjacent mainland, building nests on the ground made of twigs, leaves, grass, moss, and down.
Females lay an average of 4 eggs per clutch and incubate the nest for 21–23 days.
A study of ground-based sampling along the
McConnell River on the west coast of
Hudson Bay
Hudson Bay, sometimes called Hudson's Bay (usually historically), is a large body of Saline water, saltwater in northeastern Canada with a surface area of . It is located north of Ontario, west of Quebec, northeast of Manitoba, and southeast o ...
reported a population of about 81,000 nesting Ross's geese.
These birds migrate from their Canadian nesting grounds by mid-October, probably in response to limited food before freezing temperatures set in, and begin their return in mid-April to May.
Like most geese, they are grazers that feed on grasses, sedges, and small grains. They often forage in large mixed flocks with snow geese.
Conservation and management
The number of nesting birds in the Queen Maud Gulf hit a record low of 2,000-3,000 in the early 1950s due to extensive shooting and trapping and their subsequent sale in California markets. Hunting of Ross's geese was made illegal in the U.S. in 1931. When populations on wintering grounds began to increase again, restricted hunting was introduced.
Today, Ross's goose is protected under the
Migratory Bird Treaty Act
The Migratory Bird Treaty Act of 1918 (MBTA), codified at (although §709 is omitted), is a United States federal law, first enacted in 1918 to implement the convention for the protection of migratory birds between the United States and Canada. ...
.
References
External links
Ross's Goose - ''Chen rossii''- USGS Patuxent Bird Identification Infocenter
- Cornell Lab of Ornithology
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{{Authority control
Ross's goose
Ross's goose (''Anser rossii''), formerly ''Chen rossii'', is a white goose with black wingtips and a relatively short neck. It is the smallest of the three Anser (genus), white geese that breed in North America. It is similar in appearance to a ...
Ross's goose
Ross's goose (''Anser rossii''), formerly ''Chen rossii'', is a white goose with black wingtips and a relatively short neck. It is the smallest of the three Anser (genus), white geese that breed in North America. It is similar in appearance to a ...
Birds of the Arctic
Birds of Canada
Migratory birds (Western Hemisphere)
Ross's goose
Ross's goose (''Anser rossii''), formerly ''Chen rossii'', is a white goose with black wingtips and a relatively short neck. It is the smallest of the three Anser (genus), white geese that breed in North America. It is similar in appearance to a ...
Ross's goose
Ross's goose (''Anser rossii''), formerly ''Chen rossii'', is a white goose with black wingtips and a relatively short neck. It is the smallest of the three Anser (genus), white geese that breed in North America. It is similar in appearance to a ...