Chen canagica

NE Siberia to w Alaska; winters s Alaska to n California.

Chen canagica is restricted to the Bering Sea, breeding in Arctic and subarctic Alaska, USA and extreme north-east coastal Russia, and wintering principally along ice-free coasts of the Aleutian Islands and, in smaller numbers, in Canada and the Alaska Peninsula, with very few reaching as far south as California. Its population in Alaska declined precipitously from 139,000 in 1964 to 42,000 in 1986, but was recently estimated at c.84,500 in 2002³.

Anser canagicus is most commonly found along the Bering Sea. Main breeding populations are found in Arctic and subarctic Alaska, parts of Canada, as well as northeast Russia. They breed mainly around the Yukon-Kuskokwim Delta in Alaska. Most populations of emperor geese migrate to the Aleutian Islands during the winter.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (20,000-200,000 square km (about 8000-80,000 square miles)) More than 90 percent total breeding population is concentrated In the eastern Bering Sea region along the coast of western Alaska (Kuskokwim Bay to Kotzebue Sound), with additional nesting on St. Lawrence and Nunivak islands, and small numbers in eastern Asia, principally in the Anaydr lowlands and southern Chukotka (Eisenhauer and Kirkpatrick 1977; E. Syroechkovskiy Jr., pers. comm.). In winter, most of the population is in the Aleutian Islands, but the range extends eastward along the southern side of the Alaskan Peninsula and to the Kodiak Island Archipelago, and small numbers winter in eastern Asia, primarily in the Commander Islands. The species winters irregularly southward along the North American Pacific coast to California and in eastern Asia to Kamchatka, casually in Hawaii. Geese breeding in Siberia evidently winter and migrate with Alaskan breeding birds (Schmutz and Kondratyev 1995). Most of the global population spends spring and fall staging periods on the Alaska Peninsula (Nelson Lagoon having the greatest number). Major staging areas include the northern sides of the Alaska Peninsula and Bristol Bay, and shallow bays and lagoons near Cape Newenham and Kuskokwim Bay (AOU 1983, Eisenhauer and Kirkpatrick 1977).

Coded range extent refers to breeding range.

Adult emperor geese are small waterfowl averaging less than 3 kg and around 69 cm in length. They are sexually monomorphic with males averaging only slightly heavier than females. Emperor geese exhibit an entirely white head and nape of neck that often becomes stained a rust color by iron oxide present in a number of tidal ponds. Chin and throat are black with the rest of the body covered in gray plumage barred with black and white. Their beaks are short and light pink while their webbed feet are a bright orange. Tail feathers are white with black undertail coverts. Anser canagicus goslings are covered in downy gray feathers and usually have a black beak.

Average mass: 2.8 kg.

Average length: 68.5 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike; male larger

Length: 66 cm

Weight: 2750 grams

Habitat and Ecology

Systems

• Terrestrial
• Freshwater
• Marine

Emperor geese roost along the coast during the non-breeding season. These areas include beaches, cliffs, and dunes as well as along reefs. Emperor geese select breeding grounds that are slightly further inland into lowland marshes and meadows near a water source such as a lake or riverbed. A nearby water source is crucial to survival as geese use them to flee from land predators. Nest sites are also found on vegetated mudflats and salt marshes. Within a week of hatching, A. canagicus goslings move into tidal marsh areas closer to the coast to grow.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: tundra

Aquatic Biomes: coastal ; brackish water

Wetlands: marsh

Other Habitat Features: riparian

Comments: Nonbreeding habitat includes salt-water areas along reefs, rocky beaches, and cliff shores. Roosting may occur on beaches and dunes adjacent to intertidal areas (Petrinovich and Patterson 1983). Ice-free coasts are used in winter.

Nesting occurs in lowland marsh areas of Arctic tundra, generally not far from the coast, on edges of ponds, lakes, and potholes (AOU 1983), also on shore (e.g., among driftwood) or on low coastal or estuarine islands (Harrison 1978). Some nest sites are used in successive years, occasionally by the same female (Eisenhauer and Kirkpatrick 1977). Typical brood rearing areas in Alaska (Kokechik River area) included insides of bends of major sloughs and rivers that supported stands of Carex rariflora (Eisenhauer and Kirkpatrick 1977). On the Yukon-Kuskokwim Delta, Alaska, goslings left inland sites within one week of hatching and selected vegetated mudflats in coastal salt marsh (Laing and Raveling 1993).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Geese in the western Aleutians start spring migration in early March. A month later most have arrived at the northern side of the Alaska Peninsula. As bays clear of ice, birds move eastward; by mid-April, they have crossed Bristol Bay and begin to arrive on southern shore of Kuskokwim Bay, arriving on the Yukon-Kuskokwim Delta in early and mid-May. Geese remain at food-rich spring staging areas until nest sites are available. In nesting areas on the Seward Peninsula and in Siberia, this species may not arrive until late May or early June.

Migrating nonbreeders leave or pass through nesting grounds in late June or early July, presumably on their way to St. Lawrence Island (molting area). Fall migration begins in late August or September depending on the part of summer range occupied; nonbreeders probably depart before family groups; by September or October, geese arrive on bays on the northern side of the Alaska Peninsula and move westward and southward into islands from then until late November (Eisenhauer and Kirkpatrick 1977).

Most Emperor Geese that fail to incubate migrate in early June from the YKD to northern Chukotka in eastern Russia where they then molt their flight feathers. In some years, the number of geese undergoing this migration likely exceeds 50,000, and perhaps substantially more (Hupp et al., unpublished). The flight trajectory of geese migrating to Chukotka is directly through or over St. Lawrence Island. Data to document the timing and route of a return migration in late summer or early fall do not exist, but preliminary subsistence harvest figures from St. Lawrence Island suggest they likely fly through again at that time (T. Rothe, pers. comm.).

Very limited banding data suggests that Russian breeders migrate to fall staging and wintering areas in western Alaska (Schmutz and Kondratyev 1995).

Whereas all telemetry data for breeders on the YKD indicate that geese fly east to west to get to wintering areas, incidental observations from the Kamchatka Peninsula and the western Aleutian Islands indicate that some geese move west to east at the beginning of winter (V. Byrd and E. Syroechkovskiy, pers. comm.).

Emperor geese may form large flocks during migration.

Emperor geese feed mainly on intertidal vegetation and marine invertebrates. Vegetation includes beach rye, crowberries, beach pea, and sandwort. They are also known to eat seaweed, eelgrass, and sea lettuce. While emperor geese may eat crustaceans, they mainly consume bivalves. During the spring and autumn months their diet consists primarily of blue mussels and macoma clams. They forage for these invertebrates by submerging their head underwater to find their prey. Another method of searching for prey called “puddling” occurs on mud flats. A goose creates pools in the flats by stamping its feet and then consuming the disrupted clams. Grasses, sedges and bulbs are eaten when these birds move inland during the nesting season.

Feeding is particularly important for goslings, which are one of very few vertebrates that obtain their protein necessary for growth almost entirely from plant matter. Studies have suggested that goslings may attempt to choose more protein rich plants and specifically prefer marsh arrowgrass (Triglochin palustris) when it is available and safe to access.

Animal Foods: mollusks; aquatic crustaceans

Plant Foods: leaves; roots and tubers; algae

Primary Diet: herbivore (Folivore )

Comments: Diet includes eelgrass, marine algae, grasses, and sedges; berries when available; animal food includes mollusks and crustaceans. Foraging occurs on beaches, mud flats, in marshes, and tundra. In fall on the Alaska Peninsula, geese foraged on intertidal invertebrates in blue mussel beds or on beach pea or seabeach sandwort in vegetated habitats, the latter when mussel beds were unavailable due to tidal inundation; sometimes they foraged on clams in mud/sand habitats (Schmutz 1994).

Emperor geese are mainly herbivores, but also feed on mollusks and likely have a significant impact on their populations. It has been suggested that grazing actually increases growth of vegetation in the habitat, therefore likely benefiting many local organisms that utilize vegetation for food or cover. Nitrogen rich goose feces may also aid in vegetation growth. Adult, juvenile, and eggs of emperor geese are prey for local predators.

While some adult geese are predated by foxes and eagles, juveniles are at a much higher risk of predation. Red foxes, arctic foxes, glaucous gulls, parasitic jaegers, golden eagles, snowy owls, mink, and sandhill cranes are all potential predators of both goslings and eggs. Local humans have also been known to hunt both young and adults as well as collect eggs for subsistence.

When a predator approaches the nest, brooding females hiss, raise their wings and take on a threatening posture. Males also guard the brooding female and nest by hissing, taking on a threatening posture or charging the predator. Adults without offspring also act as a decoy and lead predators away from the nesting sites. When not with eggs or very young juveniles, emperor geese usually flee to water when approached by predators.

Known Predators:

• Glaucous gulls (Larus glaucescens)
• Red foxes (Vulpes vulpes)
• Jaegers (Stercorarius parasiticus)
• Mink (Neovison vison)
• Snowy owls (Nyctea scandiaca)
• Sandhill cranes (Grus canadensis)
• Golden eagles (Aquila chrysaetos)
• Bald eagles (Haliaeetus leucocephalus)
• Arctic foxes (Vulpes lagopus)

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 6 - 20

Comments: Occurrences have not been defined using standardized criteria, but this species appears to be represented by several distinct subpopulations.

10,000 - 100,000 individuals

Comments: In some years as many as 35,000 nesting pairs occur on the Yukon-Kuskokwim Delta, Alaska (Fischer et al. 2005).

Since 1981, emperor geese have been surveyed annually on spring staging areas in southwestern Alaska. The 2008 emperor goose survey estimate was 64,900 (USFWS 2008).

Recent aerial surveys along the eastern coast of Russia indicated a minimum of 3,000-5,000 individuals, with very few of these breeding (only 127 broods were seen) (J. I. Hodges, cited by Schmutz and Kondratyev 1995).

Emperor geese may form large flocks during molt (Soothill and Whitehead 1978).

Goslings are subject to predation by glaucous gulls until families amalgamate and increased numbers provide greater safety (Soothill and Whitehead 1978, Eisenhauer and Kirkpatrick 1977). Human harvest near villages is a locally significant mortality factor; predation and adverse weather are important mortality factors in fall staging and wintering areas (Eisenhauer and Kirkpatrick 1977). Annual survival rate of adult females varied from 44 to 69% over four years (Condor 94:398-406).

Emperor geese have two types of calls. The first (sounding like "kla-ha kla-ha") is mainly heard during migration when birds are grouped together in large numbers. The second type of call (sounding like "u-lugh u-lugh") occurs when birds are startled or threatened. These geese may also hiss when predators or other geese attempting to approach the nest. This hissing is often paired with a defensive posture or charging the threatening individual. This species of goose is known to be much less vocal than most other goose species.

Emperor geese rely mainly on their sense of sight to recognize predators or competitors. They also rely on sight to find food on land. When searching for mollusks, particularly underwater or in the mud, they primarily utilize their sense of touch. Like all birds, emperor geese perceive their environment through auditory, tactile, visual and chemical stimuli.

Communication Channels: visual ; acoustic

Comments: In fall on the Alaska Peninsula, most fed during low tides and roosted during high tides, but flocks with disproportionately more juveniles continued to feed during high tides (Schmutz 1994).

Conditions in the summer months determine whether or not juveniles will survive their first winter and migration. While the average lifespan of emperor geese has been recorded to be about 6 years with a maximum life expectancy of 12 years, many scientists believe that this is a gross underestimate. This is especially so because their longevity seems much lower than similar species. Estimated annual mortality rates range from 63 to 94% for adults.

Range lifespan
Status: wild: 12 (high) years.

Typical lifespan
Status: wild: 11 (high) years.

Average lifespan
Status: wild: 6 years.

Maximum longevity: 12 years (wild) Observations: Considering the longevity of similar species, it is likely that the longevity of these animals is somewhat underestimated.

Emperor geese exhibit a monogamous mating system, and will bond with a different goose only if the previous mate dies. Little is known about the formation of pair bonds but they are formed by the time breeding grounds are reached. Because copulation is rarely seen, it is assumed that mating occurs either just prior to or during migration to breeding grounds.

Mating System: monogamous

Upon arriving at the nesting grounds, females begin building nests. Eggs are normally laid within the first 10 days after arrival. Clutch size ranges from 3 to 8 eggs with an average of 5. Females incubate the eggs for 24 or 25 days, after which the goslings hatch over a 10 day period. Goslings hatched earlier in the breeding season have a much higher likelihood of surviving the following winter. Most goslings are fully feathered 30 to 47 days after hatching and are able to fly at 50 to 60 days old. Goslings remain close to their parents through the first winter and have even been noted to return to breeding ground with parents the following spring. Though young geese may return to breeding grounds early in life, most females do not lay eggs of their own until 3 to 4 years of age.

Emperor geese nests are commonly parasitized by other birds. A study conducted in the Yukon Delta breeding ground found that an average of 62% of nests had parasitic eggs. The majority of these eggs had been laid not by other species, but by other emperor geese. Females and males actively guard their nests but if a parasitic egg is successfully laid in or very close to a nest, the pair is highly likely to accept the egg.

Breeding interval: Emperor geese breed once yearly.

Breeding season: The breeding season occurs from late May to August.

Range eggs per season: 3 to 8.

Average eggs per season: 5.

Average time to hatching: 24 to 25 days.

Range birth mass: 74 to 81 g.

Average birth mass: 87 g.

Range fledging age: 50 to 60 days.

Average time to independence: 50 to 60 days.

Range age at sexual or reproductive maturity (female): 3 to 4 years.

Range age at sexual or reproductive maturity (male): 3 to 4 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Females are solely responsible for selecting a nest site, building a nest, and incubating the eggs. The same nest site may be used multiple years. Pairs chase rival goose species, members of their own species, as well as juveniles from previous seasons, away from their nesting sites. While both males and females defend the nesting area, males are much more aggressive than females. While the female is incubating, males remain close to the nest to fend off predators and other geese. By the end of the incubation period, females lose an average of 20.7% of their body mass due to energy being focused solely on incubating and protecting the eggs.

Once goslings hatch, they are brooded by females for the first 2 to 3 weeks. Goslings are able to forage within 24 hours of hatching. While the young feed, they stand between their parents who are both highly protective. If terrestrial predators approach and a body of water is nearby, the entire group flees to water. But if water is not close, parents surround their offspring while hissing and flapping their wings at the approaching predator. When an aerial predator strikes, juveniles hide beneath their mother’s wings as the father jumps at and attacks the predator. Males are even known to act as decoys, allowing the goslings and their mother to escape. Juveniles leave breeding grounds around the end of August but remain with their parents until the following spring, when they are chased away from the breeding grounds.

Parental Investment: precocial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Male, Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents

Clutch size is 3-8 (usually 5-6) eggs, laid generally by the second week of June, as early as late May if weather mild; median date for nest initiation is late May-early June (Petersen 1992). Incubation, by female with male nearby, lasts 24-25 days. Young first fly in early August, remain with parents until following spring. Severe weather and snow may delay nesting activity. Length of nesting season was 46-59 days over 3-year period in Alaska (Eisenhauer and Kirkpatrick 1977). Large proportion of adult females do not nest each year (Petersen 1992). Nesting is dispersed or semicolonial. In Alaska, nesting density in one study area varied from 18-27 per sq km over 2 years; highests density was 59 nests per sq, km in lowland pingo tundra (Eisenhauer and Kirkpatrick 1977).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There is 1 barcode sequence available from BOLD and GenBank.   Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen.  Other sequences that do not yet meet barcode criteria may also be available.

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Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2006
  Near Threatened
• 2004
  Near Threatened

Between 1964 and 1986 the emperor goose population in Alaska dropped from around 139,000 to 42,000 individuals. The IUCN Red list states that reasons for this decline are poorly understood. While the population has more than doubled since 1986 and current populations remain stable to slightly decreasing, emperor geese are still at risk due to hunting practices and coastal oil pollution. It is also expected that climate change may limit breeding grounds, leading to a decline in populations as well. Due to climate change, emperor geese habitat may decrease by as much as 54% by 2070.

Management plans, such as the one suggested by the Pacific Flyway Council, stress that enforcing crackdowns in illegal hunting and egg collection as well as preserving habitat and educating the public about these birds, are essential steps in protecting emperor goose populations in Alaska.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: near threatened

United States

Rounded National Status Rank: N3B,N3N : N3B: Vulnerable - Breeding, N3N: Vulnerable - Nonbreeding

Rounded Global Status Rank: G3 - Vulnerable

Reasons: Restricted range mostly in Alaska; significant decline in population 1964-1986, followed by stabilization or slight recovery; vulnerable to oil polluition; population may be limited by subsistence harvest; climate change could result in major loss of nesting habitat.

Population

Population Trend

Global Short Term Trend: Relatively stable (=10% change)

Comments: Since 1981, emperor geese have been surveyed annually on spring staging areas in southwestern Alaska (USFWS 2008). These estimates increased an average of 1% per year during 1999-2008 (P = 0.607), but this relatively stable trend masks considerable year-to-year variation. Aerial surveys during the YKD coastal survey in 2008 indicated slight decreases in the number of pairs and total birds from 2007 levels but a long-term increasing trend in both indices is still apparent. Nesting surveys conducted on the YKD during 2008 indicated clutch sizes were near average (USFWS 2008).

Global Long Term Trend: Decline of 30-70%

Comments: In Alaska, the population declined from about 139,000 in 1964 to 101,000 in 1982, with subsequent fluctuations between around 40,000-85,000 (USFWS 2008).

Degree of Threat: Medium

Comments: Subsistence hunting takes 5% of birds (1993 ICBP meeting) and spring hunting may be a limiting factor: "It is possible that subsistence harvest has been reduced enough to stop the population decline, but not enough to allow a population increase" (Petersen et al. 1994).

Emperor geese nesting in Alaska appear not to be greatly affected by increased fox predation observed on brant and cackling geese (USFWS 2008).

The species is vulnerable to oil pollution due to its restricted range and relatively small population size; major breeding and wintering areas are within sedimentary basins having high potential for oil development; probably these geese are most vulnerable when concentrated on wintering areas on the southern side of the Alaska Peninsula (Eisenhauer and Kirkpatrick 1977).

Modeling indicates that 54% of the habitat for this species could be lost by 2070 (Zöckler and Lysenko 2000).

Eisenhauer and Kirkpatrick (1977) stated that human disturbance of nests probably leads to significant egg losses to predators, but Petersen et al. (1994) state that "during pre-egg laying and incubation, pairs are little disturbed by people walking through the area or airplanes flying overhead."

Major Threats

Conservation Actions

Needs: Eisenhauer and Kirkpatrick (1977) listed the following management steps that should be considered: (1) give wildlife refuges jurisdiction over their offshore areas to regulate use for oil operations, (2) discourage tanker traffic within the range of this species, (3) develop methods to contain oil spills, (4) encourage hunters to honor regulations through increased law enforcement and education, (5) encourage and assist native corporations to secure wildlife resources for posterity by appropriate management.

There are no known adverse effects of emperor geese on humans.

Emperor geese were hunted by subsistence hunters primarily in Alaska. Historically, eggs were collected during the laying season, while juveniles and adults were hunted in the spring. Emperor geese continue to be harvested today, but many recent hunting seasons have been closed due to low population numbers. Emperor geese are also sold as pets around the world.

Positive Impacts: pet trade ; food