Common goldeneyes are medium-sized diving ducks. Males are slightly larger than females, from 45 to 51 cm in length (40 to 50 cm in females) and about 1000 grams (800 grams in females) weight. Males also have more brightly colored plumage for most of the year. Breeding males have a brilliant, greenish-black head marked with an oval, white patch at the base of the bill. Their sides, breast, belly, and secondary feathers are bright white and their back, wings, and tail are black. Female plumage is more muted, with rich brown heads, greyish backs, wings, and tails, and white sides, breasts, and bellies. Immature or eclipse males resemble females. Mature adults of both sexes have bright, deep, yellow irises, giving them the common name "goldeneye." Immature individuals have brownish irises. In flight their wings produce a whistling sound, which is characteristic.
The North American subspecies of common goldeneyes (B. c. americana) is larger overall and has a thicker bill than the Eurasian subspecies (B. c. clangula). Common goldeneyes can be confused with Barrow's goldeneyes (Bucephala islandica). However, adult male common goldeneyes have an oval white patch on the head (crescent shaped in Barrow's goldeneyes) and more white on the secondary feathers. Females are more easily confused, but female common goldeneyes have longer, sloping heads and bills and more white on the secondary feathers than female Barrow's goldeneyes. In western North America, female Barrow's goldeneyes have all yellow bills, common goldeneyes do not. This character does not work in other regions. Hatchlings of both species are also similar in appearance.
Average mass: 800-1000 g.
Range length: 40 to 51 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful
Adult females have a mean annual survival rate of from 58 to 77%, varying with study and region. Banding records in Canada suggest that males can live to 11 years and females to 12 years, although an unsexed individual was recorded living to 15 years. Hunting, predation, and diseases are noted as the leading causes of mortality in adults. Hatchlings are susceptible to cold, wet weather, which may result in mortality. Young suffer heavy mortality within the first few weeks of hatching.
Range lifespan
Status: wild: 15 (high) years.
During the breeding season, common goldeneyes are found on northern lakes and rivers that are surrounded by mature forests where tree cavities can be found for nesting. They prefer lakes with clear water and little emergent vegetation, although areas adjacent to bulrushes (Scirpus) are sometimes used for foraging. Preferred lakes are those with abundant invertebrate prey. Lakes that lack predatory fish, such as yellow perch (Perca flavescens), typically have the highest abundance of invertebrate prey.
During the winter, non-breeding season, common goldeneyes are found mainly in coastal marine and estuarine habitats and large, interior lakes and rivers. They prefer areas with shallow water and sandy, gravel, or rocky substrates. They are strong swimmers and can forage well in areas with strong current, but seem to prefer slow-flowing water. Common goldeneyes stop to refuel at large, interior lakes and rivers during migration towards coastal areas.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water
Other Habitat Features: estuarine
Common goldeneyes are found throughout North America and Eurasia. They breed in higher latitudes, from Scotland, northern Europe, and Scandinavia across northern Eurasia to the Kamchatka Peninsula and throughout much of Canada from interior British Columbia to Newfoundland. They breed also in northernmost Michigan, northeastern Minnesota, northern Montana, and portions of northern New York, Vermont, and Maine. Winter ranges include coastal North America from Alaska to Baja California, Newfoundland to Florida, and the northern Gulf of Mexico, throughout inland United States except for portions of Texas, the southeast, and Arizona, and into the Sierra Madre range of Mexico and northernmost coastal Mexico. In Eurasia they are found in coastal waters from Scandinavia to the Mediterranean, Black, and Caspian Seas and from Kamchatka to Japan. They are also found in inland lakes that remain ice-free.
Biogeographic Regions: nearctic (Native ); palearctic (Native )
Other Geographic Terms: holarctic
Common goldeneyes eat mainly aquatic insects during breeding season in northern, boreal lakes. In their winter ranges they rely on fish, crustaceans, and mollusks. They may also take some seeds and tubers. A study of 395 common goldeneyes throughout the year suggested that the majority of their diet is made up of crustaceans, insects, and mollusks (70% altogether), with the remainder made up of fish, eggs, and plant material. Diet is likely to vary regionally, but important crustaceans include crabs (Hemigrapsus, Cancer, Pagurus, Cambarus, Astacus), amphipods (Ischyrocerus, Pseudalibrotus, Gammarellus, Hyalella), shrimp, isopods, and barnacles. Important insect prey include caddisfly larvae (Trichoptera), water boatmen (Corixidae), dragonfly and damselfly nymphs (Odonata), mayfly nymphs (Ephemeroptera), and beetles (Coleoptera). Mollusk prey includes Mytilus, Lymnea, Macoma, Littorina, Nucula, Goniobasis, Nassarius, Lacuna, Bittium, and Mitrella. Fish prey may be locally important. For example, in British Columbia salmon and their eggs can make up a large portion of the diet. Other fish taken include sticklebacks (Gasterosteidae), sculpins (Cottidae), minnows (Cyprinidae), topminnows (Poeciliidae), and whitefishes (Coregonus). Plant matter taken includes freshwater pond weeds (Potomogeton, Zostera, Ruppia, Najas, Zanichellia) and spatterdock (Nymphaea).
Common goldeneyes typically hunt for prey in water less than 4 meters deep. They seem to prefer foraging in open water, although they may hunt along the edges of aquatic vegetation. They dive to catch prey and dives can be from 10 to 55 seconds long. Downy hatchlings mainly feed at the surface for their first few days but then begin short dives. Hatchlings forage in the same ways as adults, although they seem to be more selective about prey taken. They take greater proportions of dragonfly and damselfly nymphs (Odonata), caddisfly larvae (Trichoptera), and water boatmen (Corixidae). Foraging flocks often dive synchronously. Prey items are typically consumed underwater.
Animal Foods: fish; eggs; insects; mollusks; aquatic crustaceans
Plant Foods: roots and tubers; seeds, grains, and nuts
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Molluscivore )
Common goldeneyes compete directly with fish for prey and tend to be found on fish-free lakes more often than on lakes with fish. Removal of river perch (Perca flavescens) and roach (Rutilus rutilus) from a lake in Sweden resulted in increased use of that lake by common goldeneyes.
Like many other species of ducks, intraspecific nest parasitism is common in Bucephala clangula. Females whose nests are parasitized accept introduced eggs as their own but will abandon nests when too many introduced eggs are added to the nest in a short period of time. Common goldeneye females lay fewer of their own eggs when other eggs are introduced early in the egg-laying phase because they tend to brood only clutches of an optimal size. Levels of intraspecific parasitism vary substantially among populations and may be influenced by how limited nest cavities are in that area. Levels of parasitism range from 0 to 77.8% in British Columbia - seeming to vary mostly by local area and less year to year. Clutches with introduced eggs can be as large as 24, but most parasitized nests in British Columbia had less than 13 eggs in them.
Common goldeneyes are susceptible to botulism (Clostridium botulinum), avian cholera (Pasteurella multocida), and duck viral enteritis. Known parasites include several species of protozoans, flukes, and nematodes.
Mutualist Species:
Commensal/Parasitic Species:
Common goldeneyes are hunted throughout much of their range.
Positive Impacts: food
There are no known adverse effects of common goldeneyes on humans.
Common goldeneye populations seem to be relatively stable despite threats to their aquatic habitats, such as acid rain, contamination, and habitat destruction. They are considered "least concern" by the IUCN because of their large range, large population size, and no documented population declines. They are protected as a migratory bird under the U.S. Migratory Bird Act. Population densities may be most affected by availability of nest cavities.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Common goldeneyes are mainly silent outside of the courtship and nest-finding period. Males make short, faint "peent" calls during courtship displays and grunting sounds after copulation. Females make "gack" sounds that are described as harsh croaks when looking for nest sites or when disturbed. Visual signals are used in courtship and aggression.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Common goldeneyes are sometimes called "whistlers" because of the whistling noise their wings make in flight.
Most predation occurs on females and young in nests. North American predators of incubating females and hatchlings include black bears (Ursus americanus), American martens (Martes americanus), mink (Neovison vison), raccoons (Procyon lotor), hawks (Accipitridae), owls (Strigiformes), bald eagles (Haliaeetus leucocephalus), and golden eagles (Aquila chrysaetos). Hatchlings are also taken by northern flickers (Colaptes auratus), red squirrels (Tamiasciurus hudsonicus), and northern pike (Esox lucius). Hatchlings are cryptically colored and females have subdued plumage as well. Females defend their nests and broods with broken-wing displays.
Known Predators:
Anti-predator Adaptations: cryptic
Common goldeneyes are monogamous. Pair bonds are formed in December and last until the male abandons the female at the beginning of incubation. It is unknown if pair bonds last over multiple years. Males use a complex set of courtship displays from December to March to establish and maintain the pair bond. Courtship displays occur in groups of several males and females, averaging 4.4 males and 1.2 females per group. There are variations on the displays. The most spectacular is the "head-throw-kick," in which a male repeatedly thrusts his head forward, then moves it back towards his rump and utters a call. He then flicks his head forward again while kicking the water with his feet.
Mating System: monogamous
Reproduction in common goldeneyes has been well-studied because they are relatively common in northern boreal areas and nest in boxes, making them easier to observe. Females lay from 4 to 12.3 greenish eggs in a clutch and lay a single clutch each season. Clutch size estimates are difficult to determine because of the frequency of intraspecific nest parasitism, which inflates clutch sizes. in one study average clutch size was 9.77, when parasitized nests were excluded, average clutch size was 7.13 eggs. Eggs are from 61.2 to 66.6 grams. Females lay 1 egg every other day.
Common goldeneyes nest in tree cavities, but will accept nest boxes and occasionally are found in rock cavities. Females find nest cavities and line them with a nest bowl constructed of other materials and downy feathers. Preferred nesting sites seem to be those used previously with success, rather than nesting sites closer to food resources for adults or young. Nests are generally within 1.3 km of water. Females who fail to breed successfully are more likely to change nest sites between years. Changing nest sites also seems to decrease reproductive success, producing smaller clutches. Females tend to nest in the general vicinity of their previous nest or natal nest. Younger females generally lay smaller clutches later in the season and have lower reproductive success than experienced breeders. After about 6 years old, clutch sizes begin to decline. Nest mortality is mainly due to predation. Clutches laid late in the year have higher mortality rates compared to early clutches.
Females incubate the eggs for 28 to 32 days. They leave the nest occasionally during the day to forage. Eggs hatch synchronously, within 12 hours of each other. Females first breed at over 2 years old, some researchers estimate breeding starts at about 3.2 years old on average and breeding continues annually for 3.9 years.
Breeding interval: Common goldeneyes breed yearly, although some individuals do skip occasional years.
Breeding season: Breeding occurs from December through May.
Range eggs per season: 4 to 12.3.
Average eggs per season: 8.7.
Range time to hatching: 28 to 32 days.
Range fledging age: 56 to 65 days.
Range time to independence: 7 to 42 days.
Range age at sexual or reproductive maturity (female): 2 to 6 years.
Average age at sexual or reproductive maturity (female): 3.2 years.
Range age at sexual or reproductive maturity (male): 2 (low) years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Young are precocial and leave the nest 24 to 36 hours after hatching. The mother attends the nest cavity entrance until all of the young jump to the ground. Females lead their brood away from the nest site to a brooding territory up to 10 km away. Only females defend the young and brood them at night and during cold weather. Females abandon their broods before they fledge, usually around 5 to 6 weeks old, but sometimes as early as 1 week after hatching.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Although the Common Goldeneye’s bright yellow eyes give this species its name, this field mark is only visible at close range. At a distance, male Common Goldeneyes may be identified by their size (20 inches), green head, white body, patchy black-and-white wings, and, most notably, their white cheek patch. Female Common Goldeneyes have brown heads, grayish-brown bodies, and white necks. Duck hunters often refer to this duck as the “whistler” in reference to the sound its wings make in flight. The Common Goldeneye is found across the Northern Hemisphere. In North America, this species breeds across Canada, Alaska, and extreme northern portions of the lower 48. In winter, Goldeneyes migrate to coastal Canada as well as south into the United States and northern Mexico. In the Old World, this species breeds locally in northern Europe, Scandinavia and Russia, wintering south along the coast to the Mediterranean Sea and coastal China. In summer, the Common Goldeneye breeds in freshwater wetlands near forests with tree cavities in which to nest. During the winter, Common Goldeneyes are found primarily in sheltered saltwater estuaries and bays, with smaller concentrations wintering inland on ice-free lakes and rivers. The Common Goldeneye’s diet consists primarily of insects during the summer, eating mollusks, crustaceans, and fish during the winter. One of several species of “diving ducks” in North America, Common Goldeneyes may be observed submerging themselves to feed in the water or on the bottom. In winter, they may also be observed in small flocks on large, slow-moving bodies of water. This species is primarily active during the day.
Although the Common Goldeneye’s bright yellow eyes give this species its name, this field mark is only visible at close range. At a distance, male Common Goldeneyes may be identified by their size (20 inches), green head, white body, patchy black-and-white wings, and, most notably, their white cheek patch. Female Common Goldeneyes have brown heads, grayish-brown bodies, and white necks. Duck hunters often refer to this duck as the “whistler” in reference to the sound its wings make in flight. The Common Goldeneye is found across the Northern Hemisphere. In North America, this species breeds across Canada, Alaska, and extreme northern portions of the lower 48. In winter, Goldeneyes migrate to coastal Canada as well as south into the United States and northern Mexico. In the Old World, this species breeds locally in northern Europe, Scandinavia and Russia, wintering south along the coast to the Mediterranean Sea and coastal China. In summer, the Common Goldeneye breeds in freshwater wetlands near forests with tree cavities in which to nest. During the winter, Common Goldeneyes are found primarily in sheltered saltwater estuaries and bays, with smaller concentrations wintering inland on ice-free lakes and rivers. The Common Goldeneye’s diet consists primarily of insects during the summer, eating mollusks, crustaceans, and fish during the winter. One of several species of “diving ducks” in North America, Common Goldeneyes may be observed submerging themselves to feed in the water or on the bottom. In winter, they may also be observed in small flocks on large, slow-moving bodies of water. This species is primarily active during the day.
The common goldeneye or simply goldeneye (Bucephala clangula) is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Its closest relative is the similar Barrow's goldeneye.[2] The genus name is derived from the Ancient Greek boukephalos ("bullheaded", from bous, "bull " and kephale, "head"), a reference to the bulbous head shape of the bufflehead. The species name is derived from the Latin clangere ("to resound").[3]
Common goldeneyes are aggressive and territorial ducks, and have elaborate courtship displays.[2]
Adult males ranges from 45–51 cm (18–20 in) and weigh approximately 1,000 g (2.2 lb), while females range from 40–50 cm (16–20 in) and weigh approximately 800 g (1.8 lb).[2] The common goldeneye has a wingspan of 30.3-32.7 in (77-83 cm).[4] The species is named for its golden-yellow eye. Adult males have a dark head with a greenish gloss and a circular white patch below the eye, a dark back and a white neck and belly. Adult females have a brown head and a mostly grey body. Their legs and feet are orange-yellow.
Two subspecies are generally recognized, the nominate Eurasian subspecies Bucephala clangula clangula and the North American B. c. americana. americana has a longer and thicker bill than clangula. [5]
Their breeding habitat is the taiga. They are found in the lakes and rivers of boreal forests across Canada and the northern United States, Scotland, Scandinavia, the Baltic States, and northern Russia. They are migratory and most winter in protected coastal waters or open inland waters at more temperate latitudes.[2] Naturally, they nest in cavities in large trees, where they return year after year,[6] though they will readily use nest boxes as well.[7]
Natural tree cavities chosen for nest sites include those made by broken limbs and those made by large woodpeckers, specifically pileated woodpeckers or black woodpeckers.[8] Average egg size is a breadth of 42.6–44.0 mm (1.68–1.73 in), a length of 58.1–60.6 mm (2.29–2.39 in) and a weight of 61.2–66.6 g (2.16–2.35 oz).[2] The incubation period ranges from 28 to 32 days. The female does all the incubating and is abandoned by the male about 1 to 2 weeks into incubation. The young remain in the nest for about 24–36 hours. Brood parasitism is quite common with other common goldeneyes,[9] and occurs less frequently with other duck species. The broods commonly start to mix with other females' broods as they become more independent or are abandoned by their mothers.[10] Goldeneye young have been known to be competitively killed by other goldeneye mothers, common loons and red-necked grebes.[2] The young are capable of flight at 55–65 days of age.
Common goldeneyes are diving birds that forage underwater. Year-round, about 32% of their prey is crustaceans, 28% is aquatic insects and 10% is molluscs.[11] Insects are the predominant prey while nesting and crustaceans are the predominant prey during migration and winter. Locally, fish eggs and aquatic plants can be important foods. They themselves may fall prey to various hawks, owls and eagles, while females and their broods have been preyed upon by bears (Ursus spp.), various weasels (Mustela spp.), mink (Mustela vison), raccoons (Procyon lotor) and even northern flickers (Colaptes auratus) and red squirrels (Tamiasciurus husonicus).
The common goldeneye is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. Approximately 188,300 common goldeneyes were killed annually by duck hunters in North America during the 1970s, representing slightly less than 4% of the total waterfowl killed in Canada during that period, and less than 1% of the total waterfowl killed in the US.[12] Both the breeding and winter habitat of these birds has been degraded by clearance and pollution. However, the common goldeneye in North America is known to derive short-term benefits from lake acidification.[13]
Male portrait
Female portrait
just after a dive - showing clear nictitating membrane
In flight over Rideau River, Ottawa, Ontario
.jpg)
With a northern crayfish (Orconectes virilis)
Bucephala clangula Pair .jpg)
Female goldeneye with chicks The common goldeneye or simply goldeneye (Bucephala clangula) is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Its closest relative is the similar Barrow's goldeneye. The genus name is derived from the Ancient Greek boukephalos ("bullheaded", from bous, "bull " and kephale, "head"), a reference to the bulbous head shape of the bufflehead. The species name is derived from the Latin clangere ("to resound").
Common goldeneyes are aggressive and territorial ducks, and have elaborate courtship displays.
