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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
Perception Channels: visual ; tactile ; acoustic ; chemical
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
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
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.
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 )
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 )
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
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.
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
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:
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 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: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
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
The emperor goose (Anser canagicus), also known as the beach goose[6] or the painted goose,[7] is a waterfowl species in the family Anatidae, which contains the ducks, geese, and swans. In the winter, the emperor goose lives in mudflats and coasts in Alaska and occasionally Canada and the contiguous United States. In the summer, it migrates northerly several hundred miles to arctic and sub-arctic climates, where older individuals breed monogamously. Listed as near threatened by the International Union for Conservation of Nature, the species' population is declining due to threats such as pollution, hunting, and climate change.
The emperor goose was described in 1802 as Anas canagica. Its type locality is Kanaga Island, which is located in the Aleutian Islands, Alaska. The species has sometimes been classified in the genus Chen and less commonly in its own genus, Philacte.[8]
The emperor goose has a stout blue-gray body,[6] with spots of black and white, which cause it to have a "scaled appearance".[9] Its head and the back of its neck are white and tinged with amber-yellow;[7] unlike the snow goose, the white does not extend to the front of the neck.
The goose is also characterized by a black chin and throat, a white tail, a pink bill, which is tipped with white, and yellow-orange legs and feet.[7][10] The underside of the emperor goose's wings is gray, unlike the snow goose, which has black and white on the underside of its wings. The head of adults frequently turns to a reddish-brown color in summer, due to its feeding in tidal pools with iron oxide.[10]
Goslings (i.e. young shortly after hatching) are grayish-white colored; unlike adults, their bill is black. Goslings are also distinguished from adults by having gray, brown, or black feet and an area of white surrounding the bill for the first three weeks after hatching.
Juveniles (i.e. immature specimens older than goslings) are mostly gray colored, with a small amount of white on their feathers. Younger juveniles have a dark head and neck,[10] with their head being dusty-colored with patches of white.[7] However, after October, their head and upper neck turn to mostly white, although they still have scattered darker feathers. By the first winter, juveniles have the same coloring and features as adults.[10]
Adult males grow to a total length of 26–28 inches (66–71 cm) and females 25.6–27.5 inches (65–70 cm).
Other measurements in males, sampled from four specimens in Alaska and California, include a 2.5–2.98-inch (6.4–7.6 cm) tarsus (lower leg), a 1.42–1.6-inch (3.6–4.1 cm) bill, and a 13.5–15.5-inch (34–39 cm) folded wing. These measurements are similar in females, but females have a slightly shorter folded wing of 14.75–15.45 inches (37.5–39.2 cm) based on two Alaskan individuals.[11] The goose has a wingspan of 119 centimetres (47 in).[8] Because of its short wings, it flies slowly, requiring quick strokes.[10]
Males weigh between 2.766 kilograms (6.10 lb) and 3.129 kilograms (6.90 lb). They have a mean weight of 2.316 kilograms (5.11 lb), while females have a mean weight of 1.945 kilograms (4.29 lb).[8] The average weight of juveniles is 1.165 kilograms (2.57 lb) in males and 1.107 kilograms (2.44 lb) in females. Roughly 5–7.5 weeks after hatching, the goose averages a weight of 2.370 kilograms (5.22 lb) and 1.926 kilograms (4.25 lb) in males and females, respectively.[10] It has a heavy body and short neck compared to other geese.[12] Although the species can live to age 25 in captivity, it reaches age 12 in the wild.[13]
The emperor goose is migratory, traveling north in the summer to breed and south for the winter.[14] Unlike many goose species, which migrate thousands of miles, the emperor goose travels a few hundred miles for migration,[15] usually about 370 miles (600 km) to 470 miles (760 km).[8] Breeding birds molt near the breeding colonies, but geese unsuccessful with breeding move to either St. Lawrence Island or the Chukchi Peninsula to molt prior to the main southerly migration for winter.[16]
The breeding season starts in late June in Russia, but begins a few weeks earlier in Alaska, generally between 20 May and 3 June.[8] Only individuals three years or older will mate. A monogamous species, female emperor geese have a single mate throughout their life and only mate with any other male if their mate dies.[13] The species molts from late July to early August and leaves its breeding grounds later than any other species.[11]
The emperor goose breeds on tundra, building its nests in areas 10 miles (16 km) or closer to the coast.[14] The nests are typically constructed in marshes.[11] They are built as holes in the ground without containing nesting material, but are later built up with vegetation, such as leaves,[7] and feathers, which the female plucks from herself.[11]
The species usually lays 4–6 eggs, but it can lay anywhere from 2 to 8; eggs are often laid in the nests of other emperor geese families.[14] Eggs measure 7.86 centimetres (3.09 in) by 5.21 centimetres (2.05 in) on average, with an elliptical shape and a smooth shell. They are initially white colored, but become speckled with stains from their nest.[12] Egg incubation, usually lasting 24 days, is performed only by females.[14]
According to The Game Birds of California, a 1918 book, surveys of the species' nests showed that the male did not stay with the nest. However, the Beardsley Zoo says that although the male does not help build the nest, it defends it. The eggs hatch in late June and early July.[11] Exhibiting precociality, young are able to walk and swim hours after hatching,[14] as well as feed themselves. They typically vacate the nest the same day as their hatching, although they do not wander far from their parents until after two months.[13] Young can fly once 50−60 days old.[14] 10% of emperor geese remain alive after their first year.[13]
Individuals of the species usually only interact with their family; however, larger flocks collect during the breeding season and the molting season.[13] It is one of the most unsocial goose species; the only goose less social than it is the black brant.[11] It stays low when flying, usually keeping below 90 feet (27 m) above the ground and often coming close to touching the ground with its wings.[12]
In the summer, the species' diet consists of vegetation, such as shoots, roots, and berries, while in the winter it primarily eats bivalve molluscs (which it uses its sense of touch to catch)[13] and algae.[14]
Unlike other goose species,[10] its diet mostly consists of animals,[12] causing its flesh to have a strong flavor.[12] When living near water, it eats at the edge of water bodies, which has given it the name "Beach Goose".[6] If the species feels threatened, it goes into a body of water and swims away until the threat is a safe distance from it.[13]
Its vocalizations, according to Edward William Nelson, sound like "kla-ha, kla-ha, kla-ha",[12] and can be differentiated from those of other geese by having a more "nasal" sound.[8] It vocalizes less often than other geese, such as the white-fronted goose.[12]
During the summer, the emperor goose lives in Arctic and subarctic climates in the Bering Sea, around Alaska and a small part of northeast Russia.[17] Its habitats in this season include freshwater pools, inland lakes, and coastal lagoons.[13] 90% of specimens nest on the Yukon-Kuskokwim Delta.[15] In the winter, after its southerly migration, it lives primarily among the Aleutian Islands,[1] as well as on the Alaska Peninsula and the Kodiak Island.[15] It sometimes spends winters in Canada[1] and rarely as far south as northwestern California. Some areas in California the species has been found living in, as of 1918, include Humboldt Bay, Gridley, Davis, Rio Vista, Colusa County, Ingomar, Modesto, and Dixon.[11] Its habitats are mudflats and rocky shores in the winter,[14] in areas free of ice,[17] and tundra wetlands in the summer.[9] Its extent of occurrence is estimated to be 775,000 square kilometres (299,000 sq mi).[1]
As of August 2017, the emperor goose's population is increasing slowly.[18] In 1879, the emperor goose was found by Edward William Nelson to be abundant along the Yukon-Kuskokwim Delta.
In 1923, however, Arthur Cleveland Bent observed much fewer specimens, and reported that the population had decreased over the past 30 years prior to that. Bent said that "large numbers are killed each year and their eggs taken by the natives, even within the limits of what is supposed to be a reservation", which was a major reason for the goose's decrease in population.[12] In 1964, the goose's population was 139,000, which decreased to 42,000 in 1986.
The population subsequently increased,[6] with its population having been 85,000 in 2002 and over 98,000 in 2015;[19] According to the emperor goose's entry on the Red List of the International Union for Conservation of Nature (IUCN), which was entered on 1 October 2016, the total population of the emperor goose is decreasing.
However, it also said that the trend is not clear and it is increasing in parts of North America.[1] Julian Fischer, a wildlife biologist, said in a news article published in August 2017, that the population has been experiencing a slow, steady increase.
He stated that the population had over doubled in size from the early 1980s, and that it may be as large as 170,000.[18]
Although the reasons for the emperor goose's population decline are not well known, it is believed to be threatened by oil pollution, hunting, and climate change.[1]
Other factors contributing to the species' population decline include competing with the cackling goose for food and the preying of goslings.[10] The emperor goose is listed as near threatened on the IUCN Red List[1] and rated 14 out of 20 on the Continental Concern Score. The 2016 State of North America's Birds' Watch List, a list of threatened birds that have no major conservation actions taking place for them, includes the emperor goose.[19]
Due to its low population in the 1980s, recreational and subsistence hunts closed for the goose in 1986 and 1987, respectively. However, 30 years later, hunts became legal again after the population grew significantly. In 2015, the Alaska Migratory Bird Co-Management Council suggested for hunting of the bird to be allowed if the population were to grow to a certain number. On 2 April 2017, subsistence hunting was allowed for the emperor goose, with hunters able to kill an unlimited number of geese. In fall 2017, emperor geese were allowed to be hunted for recreational purposes by locals of Alaska with a permit, with a limit of one bird per person.
In 2018, hunters who were not residing in Alaska were permitted to hunt the geese with a permit. However, the species cannot be hunted anywhere in the contiguous United States.[15][18]
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 the winter, the emperor goose lives in mudflats and coasts in Alaska and occasionally Canada and the contiguous United States. In the summer, it migrates northerly several hundred miles to arctic and sub-arctic climates, where older individuals breed monogamously. Listed as near threatened by the International Union for Conservation of Nature, the species' population is declining due to threats such as pollution, hunting, and climate change.
