- Snow Goose
Snow Goose C. c. caerulescens white morph Conservation status Scientific classification Kingdom: Animalia Phylum: Chordata Class: Aves Order: Anseriformes Family: Anatidae Subfamily: Anserinae Tribe: Anserini Genus: Chen Species: C. caerulescens Binomial name Chen caerulescens
- C. c. caerulescens (Lesser Snow Goose) (Linnaeus, 1758)
- C. c. atlanticus (Greater Snow Goose) (Kennard, 1927)
Blue: breeding ground. Ochre: wintering ground. Synonyms
Anser caerulescens (but see text)
The Snow Goose (Chen caerulescens), also known as the Blue Goose, is a North American species of goose. Its name derives from the typically white plumage. The genus of this bird is disputed. The American Ornithologists' Union and BirdLife International place this species and the other "white geese" in the Chen genus, while other authorities follow the traditional treatment of placing these species in the "gray goose" genus Anser.[unreliable source?]
This goose breeds north of the timberline in Greenland, Canada, Alaska, and the northeastern tip of Siberia, and winters in warm parts of North America from southwestern British Columbia through parts of the United States to Mexico. It is a rare vagrant to Europe, but a frequent escape from collections and an occasional feral breeder. Snow Geese are visitors to the British Isles where they are seen regularly among flocks of Barnacle, Brent and Greenland White-fronted geese. There is also a feral population in Scotland from which many vagrant birds in Britain seem to derive.
The Snow Goose has two color plumage morphs, white (snow) or gray/blue (blue), thus the common description as "snows" and "blues." White-morph birds are white except for black wing tips, but blue-morph geese have bluish-grey plumage replacing the white except on the head, neck and tail tip. The immature blue phase is drab or slate-gray with little to no white on the head, neck, or belly. Both snow and blue phases have rose-red feet and legs, and pink bills with black tomia ("cutting edges"), giving them a black "grin patch." The colors are not as bright on the feet, legs, and bill of immature birds. The head can be stained rusty-brown from minerals in the soil where they feed. They are very vocal and can often be heard from more than a mile away.
White- and blue-morph birds interbreed and the offspring may be of either morph. These two colors of geese were once thought to be separate species; since they interbreed and are found together throughout their ranges, they are now considered two color phases of the same species. The color phases are genetically controlled. The dark phase results from a single dominant gene and the white phase is homozygous recessive. When choosing a mate, young birds will most often select a mate that resembles their parents' coloring. If the birds were hatched into a mixed pair, they will mate with either color phase.
The species is divided into two subspecies on the basis of size and geography. Size overlap has caused some to question the division. The smaller subspecies, the Lesser Snow Goose (C. c. caerulescens), lives from central northern Canada to the Bering Straits area. The Lesser Snow Goose stands 25 to 31 inches (63 to 79 cm) tall and weighs 4.5 to 6.0 pounds (2.0 to 2.7 kg). The larger subspecies, the Greater Snow Goose (C. c. atlanticus), nests in northeastern Canada. It averages about 3.2 kg (7.1 lb) and 79 cm (31 in), but can weigh up to 4.5 kg (9.9 lb). The wingspan for both subspecies ranges from 135 to 165 cm (53 to 65 in). Blue-morph birds are rare among the Greater Snow Geese and among eastern populations of the Lesser.
Long-term pair bonds (they mate for life) are usually formed in the second year, although breeding does not usually start until the third year. Females are strongly philopatric, meaning they will return to the place they hatched to breed.
Snow Geese often nest in colonies. Nesting usually begins at the end of May or during the first few days of June, depending on snow conditions. The female selects a nest site and builds the nest on an area of high ground. The nest is a shallow depression lined with plant material and may be reused from year to year. After the female lays the first of 3 to 5 eggs, she lines the nest with down. The female incubates for 22 to 25 days, and the young leave the nest within a few hours of hatching.
The young feed themselves, but are protected by both parents. After 42 to 50 days they can fly, but they remain with their family until they are 2 to 3 years old.
Where Snow Geese and Ross's Geese breed together, as at La Pérouse, they hybridize at times, and hybrids are fertile. Rare hybrids with the Greater White-fronted Goose, Canada Goose, and Cackling Goose have been observed.
The breeding population of the Lesser Snow Goose exceeds 5 million birds, an increase of more than 300 percent since the mid-1970s. The population is increasing at a rate of more than 5 percent per year. Non-breeding geese (juveniles or adults that fail to nest successfully) are not included in this estimate, so the total number of geese is even higher. Lesser Snow Goose population indices are the highest they have been since population records have been kept, and evidence suggests that large breeding populations are spreading to previously untouched sections of the Hudson Bay coastline.
Snow geese breed from late May to mid August, but they leave their nesting areas and spend more than half the year on their migration to-and-from warmer wintering areas. During spring migration, large flocks of snow geese fly very high along narrow corridors, more than 3000 miles from traditional wintering areas to the tundra.
The Lesser Snow Goose travels through the Central Flyway, across some of the richest farmland in America. Traditionally, the geese wintered in coastal marsh areas where they used those short but very strong bills to dig the roots of marsh grasses for dinner. The first transition was to rice fields, where the geese could graze on weeds and eat the grain left behind by the combine. A decade later the geese had mastered field feeding and had diversified into wheat, corn, sorghum and practically any other field grain they encountered. The geese had also begun to graze in fall-seeded grain fields, especially winter wheat. Snow Geese now feed in grain fields as soon as they reach the prairies in September, and they continue to use agricultural fields until they leave the prairies in April and May on their way to Arctic breeding areas.
Many biologists think the shift in winter feeding has led to the over-abundance of geese. Winter may be the time of year that sets the upper limit to goose populations. Now, the abundance of waste agricultural grain has provided Snow Geese with excellent forage and has improved the survival of wintering geese. The national wildlife refuges bought to protect habitat also help to increase survival. Therefore, more geese are returning to the Arctic to breed each spring. Those returning geese are in much better physical condition than was the case when geese did not use agricultural grain but foraged in marshland.
Outside of the nesting season, they usually feed in flocks. In winter, snow geese feed on left-over grain in fields. They migrate in large flocks, often visiting traditional stopover habitats in spectacular numbers. Snow geese often travel and feed alongside white-fronted geese; in contrast, the two tend to avoid travelling and feeding alongside Canada grey geese, who are often heavier birds.
The population of Greater Snow Geese was in decline at the beginning of the 20th century, but has now recovered to sustainable levels. Snow Geese in North America have increased to the point where the tundra breeding areas in the Arctic and the saltmarsh wintering grounds are both becoming severely degraded, and this affects other species using the same habitat.
Major nest predators include Arctic Foxes and Skuas. The biggest threat occurs during the first couple of weeks after the eggs are laid and then after hatching. The eggs and young chicks are vulnerable to these predators, but adults are generally safe. They have been seen nesting near Snowy Owl nests, which is likely a solution to predation. Their nesting success was much lower when snowy owls were absent, which leads scientists to believe that the owls, since they are predatory, were capable of keeping predators away from the nests.[unreliable source?] Few predators take snow geese away from the nests, but Bald Eagles do take them given the chance.
- ^ Chen caerulescens, ITIS report
- ^ a b Anser caerulescens, Animal Diversity
- ^ a b c Mowbray et al. (2000)
- ^ Herrera et al. (2006)
- BirdLife International (2004). Chen caerulescens. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern.
- Herrera, Néstor; Rivera, Roberto; Ibarra Portillo, Ricardo & Rodríguez, Wilfredo (2006): Nuevos registros para la avifauna de El Salvador. ["New records for the avifauna of El Salvador"]. Boletín de la Sociedad Antioqueña de Ornitología 16(2): 1–19. [Spanish with English abstract] PDF fulltext
- Johnson, Mike. 1997. The snow goose population problem. Northern Prairie Wildlife Research Center Online.  (Version 16JUL97).
- Mowbray, Thomas B., Fred Cooke and Barbara Ganter. 2000. Snow Goose (Chen caerulescens), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved 2009-04-10. Subscription required.
- US Fish & Wildlife Service
- Snow Goose Species Account – Cornell Lab of Ornithology
- The Nature Conservancy's Species profile: Snow Goose Learn more about the conservation of these geese
- Picture Link: Snow Geese taking flight in Addison, VT
- Snow Goose Information and Photos – South Dakota Birds and Birding
- Snow Goose Chen caerulescens – USGS Patuxent Bird Identification InfoCenter
- Avibase Links to Flickr Handguide
- Song of the North Wind: A Story of the Snow Goose by Paul A. Johnsgard (1974, rev. 2009)
- Snow Goose videos, photos, and sounds on the Internet Bird Collection
Game animals and shooting in North America Game birds Waterfowl Big game Other quarry See also
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Look at other dictionaries:
Snow goose — Snow Snow, n. [OE. snow, snaw, AS. sn[=a]w; akin to D. sneeuw, OS. & OHG. sn[=e]o, G. schnee, Icel. sn[ae]r, snj[=o]r, snaj[=a]r, Sw. sn[ o], Dan. snee, Goth. snaiws, Lith. sn[ e]gas, Russ. snieg , Ir. & Gael. sneachd, W. nyf, L. nix, nivis, Gr.… … The Collaborative International Dictionary of English
Snow Goose — (Myoko,Япония) Категория отеля: 2 звездочный отель Адрес: 949 2112 Ниигата, Myoko, Sekika … Каталог отелей
snow goose — snow′ goose n. orn a white North American goose, Chen caerulescens, with black primary feathers • Etymology: 1765–75, amer … From formal English to slang
snow goose — n. a wild, medium sized, white goose (Anser caerulescens) with a reddish bill and black wing tips, that breeds in the Arctic and has a bluish gray color phase if it migrates farther south … English World dictionary
snow goose — a white North American wild goose, previously classified as the species Chen hyperborea but now considered the light color phase of the blue goose, C. caerulescens. [1765 75, Amer.] * * * ▪ bird a species of North American goose that may be… … Universalium
snow goose — noun blue goose in the white color phase • Hypernyms: ↑blue goose, ↑Chen caerulescens * * * noun : a wild goose of the genus Chen (C. caerulescens) that is usually white with blackish primaries and a reddish or pinkish bill but exists in a… … Useful english dictionary
Snow Goose — snieginė žąsis statusas T sritis zoologija | vardynas atitikmenys: lot. Anser caerulesceus angl. Snow Goose vok. Schneegans … Paukščių anatomijos terminai
snow goose — snieginė žąsis statusas T sritis zoologija | vardynas atitikmenys: lot. Anser caerulescens; Chen caerulescens angl. snow goose vok. Schneegans, f rus. белый гусь, m pranc. oie des neiges, f ryšiai: platesnis terminas – tikrosios žąsys … Paukščių pavadinimų žodynas
snow goose — noun Date: 1771 a North American goose (Chen caerulescens syn. Anser caerulescens) that has a pinkish bill and exists either as a white form with black primaries or as a grayish black form with a white head … New Collegiate Dictionary
snow goose — noun a gregarious goose that breeds in Arctic Canada and Greenland, typically having white plumage with black wing tips. [Anser caerulescens.] … English new terms dictionary