Bucephala islandica

Geographic Range

Barrow’s goldeneyes ( Bucephala islandica ) have a discontinuous distribution that consists of three separate populations. Approximately 150,000 to 200,000 birds are distributed west of the North American Rocky Mountains in aquatic habitats, from Montana to southeastern Alaska. There are smaller separated populations consisting of approximately 4,500 birds found in northeastern North America, from the shores of the Gulf of St. Lawrence, extending downward into Maine. Smaller resident populations consisting of 2,000 can also be found in Greenland and Iceland. Oddly, the eastern and western populations show little variation and are seemingly identical on the Atlantic and Pacific coasts although the populations do not share similar boundaries.

Wintering areas for western populations extend from southeastern Alaska to central California, with most wintering birds found in the San Francisco Bay and other large open water areas of the northwestern states. Eastern populations can be localized in the Gulf of St. Lawrence and parts of the northeastern States.

• Biogeographic Regions
• nearctic nearctic
  • native native
• palearctic palearctic
  • native native

• Other Geographic Terms
• holarctic holarctic

Habitat

During the breeding season, Barrow’s goldeneyes are primarily associated with invertebrate-rich freshwater and alkaline lakes that are surrounded by mature boreal forests, where tree cavities can be found for nesting. Although uncommon, mating Barrow’s Goldeneyes can be associated with subalpine lakes, beaver ponds, and small sloughs in western intermountain areas. Eastern populations of Barrow’s goldeneyes prefer the same conditions, but can be more assorted with small fishless lakes.

Wintering Barrow’s goldeneyes migrate towards coastal areas and are mainly found in rocky coastal marine and estuarine habitats, including bays, inlets, harbors and large, interior lakes and rivers. Preferring shallower ice-free waters, strong swimming Barrow’s goldeneyes forage in areas with strong currents, but seem to prefer slow-flowing water.

• Habitat Regions
• polar polar
• saltwater or marine saltwater or marine
• freshwater freshwater

• Terrestrial Biomes
• forest forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• coastal coastal

• Other Habitat Features
• estuarine estuarine

Physical Description

Adult Barrow’s goldeneyes are similar in appearance to common goldeneyes . They are a chunky-bodied, medium-sized diving duck, with a large, puffy head and a short neck. Males are slightly larger than females, averaging 48 cm in length, compared to 43 cm among females, and weigh 1278 grams, compared to 818 grams for females. Breeding males have dazzling plumage, an iridescent purplish-black, crescent-shaped head, with a single white patch on each side of the face at the base of the bill and eyes. Their sides, breast, belly, and secondary feathers are bright white and their back, wings, and tail are a deep black. These birds also have a series of seven white squares running along the sides of their body. Females have dual-colored plumage: with a rich-brown head, greyish backs, wings, and tails, and white sides, breasts, and bellies. Immature or eclipse males resemble females. Both males and females have a short, triangular bill. Mature adults of both sexes have bright, deep yellow irises, hence the common name "goldeneye”. During flight, their high-speed wings produce a whistling sound.

Barrow’s goldeneyes can be confused with common goldeneyes . However, adult male Barrow’s goldeneyes have a crescent-shaped white patch on the sides of their head, which is oval-shaped in common goldeneyes, and fewer white secondary feathers. Females are more easily confused; but female Barrow’s goldeneyes have shorter, sloping heads and broader bills, which taper abruptly to a narrower tip. Hatchlings of both species are also similar in appearance.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful

Reproduction

They are generally monogamous and form pairs while on wintering grounds. However, male Barrow’s goldeneyes can be considered polygynous. Males, also known as drakes, can form simultaneous pair bonds with two females. It is suggested that polygyny in Barrow's goldeneyes is not a common breeding strategy, but is rather an unusual occurrence. Males conduct an assortment of physical displays and vocalizations during courtship. These displays are similar to the displays of common goldeneyes . Displays include turning their heads and pulling them back at varying speeds, holding their heads up and swinging them backwards with their bills pointed vertically, and lifting their head up and down with a straight neck.

It is unknown if pair bonds last over multiple years, although some researchers propose Barrow’s goldeneyes pair long-term. Forced copulation is common in waterfowl; however, it has never been documented in Barrow’s goldeneyes. Drake Barrow’s goldeneyes take several minutes before mounting a prone female; this delay implies a strong bond.

• Mating System
• monogamous monogamous

Barrow’s goldeneyes are secondary cavity nesters, they use abandoned nests constructed by other species, usually excavated by pileated woodpeckers and northern flickers . Their nests are hollowed out tree cavities, typically white birch . They also appear to rely on the availability of natural cavities formed in large, decaying trees for nesting. In recent decades, nesting females have benefited from man-made nest boxes. Many female Barrow's goldeneyes typical do not start breeding until the age of three years. When females become sexual mature, they begin to seek out and select suitable nest sites, accompanied by males. Once chosen, the nest is lined with downy feathers from the female’s breasts.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Female Barrow’s goldeneyes usually lay a clutch of around 6 to 12 blue-green or olive-green eggs, which are incubated for 29 to 31 days. Females may leave the nest occasionally during the day to forage. Young Barrow’s goldeneyes are well-developed at hatching, and are able to leave the nest within the first day. After using their long tails and sharp claws to climb the inner side of the nest cavity, young Barrow’s goldeneyes must make the long jump from the nest entrance to the ground, encouraged by the female calling to them from below. Young Barrow’s goldeneyes have been known to leap from great heights without injury because of their puffy down feathers, which cushion their fall.

• Parental Investment
• precocial precocial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Barrow’s goldeneyes are rather long-lived, with a single individual reaching 18 years of age. According to the USGS, an individual Barrow’s goldeneye was banded one year after hatching in Alaska in 1965 and killed later in 1979, reaching nearly 16 years in age. No extensive studies on lifespan in captivity have been conducted. Several studies suggest that longevity is linked to food availability, stable environment, and absence of disease and toxic materials such as lead and mercury.

Behavior

Barrow’s goldeneyes devote their time to preening, swimming, diving, perching, flying, and foraging, with most of their time allocated in the water. Their gross morphology is built for diving and swimming, however, this hinders their ability to become airborne quickly. Instead of springing straight up out of the water into flight, as puddle ducks do, Barrow’s goldeneyes must run across the water to build up speed before taking off. Their principal daytime activity is foraging, comprising of most of their time. They typically forage in small groups, diving synchronously to search for prey. Their remaining time consists of preening and bathing while on the surface of the water or on the shoreline. Moderately social outside of the breeding season, Barrow’s goldeneyes can be observed in flocks of 5 to 10 and rarely in flocks of more than 50. However, migrating flocks gather with other groups into large flocks at rest sites. It is not unusual for Barrow’s goldeneyes to forage with different waterfowl species. Flight is rapid, with strong wing beats.

• Key Behaviors
• flies
• natatorial natatorial
• diurnal diurnal
• motile motile
• migratory migratory
• social social

Home Range

Populations of Barrow’s goldeneyes migrate between their summer breeding ranges and wintering grounds. They are often one of the last ducks to leave their summer grounds and winter as far north as possible in ice-free areas. They can be aggressive and territorial in the spring. Males defend territory, and females defend the immediate area around the nest-site. Paired drakes defend territories on their breeding ponds until mid-incubation. The size of a breeding territory varies depending on the location but it ranges from 0.18 to 1.45 ha. Many female Barrow's goldeneyes return to the same breeding locations year after year. In some cases, these birds may also defend their winter territories.

Communication and Perception

Barrow’s goldeneyes are mainly silent, except in courtship when males gives a short "ka-KAA," and near nests, where female makes short soft "cuc" notes. In flight, their wings produce a whistling sound. Visual signals are also used in courtship and aggression.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Barrow’s goldeneyes consume a variety of aquatic organisms. Their diet consists of mussels , snails , limpets , crustaceans , isopods , fish eggs, algae , and vascular plants. Their diet likely varies regionally as well as seasonally. Blue mussels are an essential food source of Barrow’s goldeneyes in the coastal waters of British Columbia. During the spring, fish eggs, such as salmon and herring eggs, make up a large portion of their diet. Barrow’s goldeneyes typically hunt for prey in water less than 4 meters deep, although they may hunt in deeper water. They prefer to forage in open water, although they can be frequently found along rocky shorelines inhabited by mussels. Prey is swallowed while submerged under the water. Adults may dive for 10 to 50 seconds, while downy young only dabble in their first few weeks. Individuals in flocks tend to dive and surface in a highly synchronous fashion. Synchrony allows for groups to maintain cohesion and a watchful eye during foraging trips.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • eats non-insect arthropods
  • molluscivore molluscivore
• herbivore herbivore
  • granivore granivore
• omnivore omnivore

• Animal Foods
• fish
• eggs
• insects
• mollusks
• aquatic crustaceans

• Plant Foods
• roots and tubers

Predation

Barrow’s goldeneyes remain susceptible to an assortment of predators. Most predation occurs on nesting females and hatchlings. Predators include American black bears , raccoons , bald eagles , hawks , owls , and weasels such as American martens and fishers . Large predatory fish, like northern pike and muskellunges may also prey on more vulnerable, immature hatchlings. Non-native European starlings also destroy eggs in attempts to seize nest cavities. Young Barrow’s goldeneyes often escape predators by diving underwater.

Ecosystem Roles

Barrow’s goldeneyes compete for suitable nest sites with species like common goldeneyes , buffleheads , squirrels , northern flickers , and invasive species like European starlings . Barrow’s goldeneyes also compete directly with fish for prey and tend to breed and forage on fish-free lakes. Similar to many other duck species, intraspecific nest parasitism is common. Barrow’s goldeneyes are particularly noted as brood parasites. Being a brood parasite has several benefits. The parasitic parent does not have to build its own nest, incubate eggs, or care for chicks. The host female, whose nest is parasitized, accepts introduced eggs as her own and raises the parasite chicks alongside her own brood. Like many ducks, Barrow’s goldeneyes are prone to infections by a variety of parasites. External parasites like leeches , lice , biting mosquitoes and flies , fleas , mites , and ticks frequently infest Barrow’s goldeneyes. Barrow’s goldeneyes are also susceptible to botulism and avian cholera .

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Barrow’s goldeneyes help regulate populations of prey species including fish, insects , mollusks , and crustaceans . This species of duck is also actively targeted by sportsman during fall and winter hunting seasons.

• Positive Impacts
• food food

Economic Importance for Humans: Negative

There are no known adverse effects of Barrow’s goldeneyes on humans.

Conservation Status

Barrow’s goldeneyes are protected under the Canada-U.S. Migratory Birds Convention and are listed as “least concern” on the IUCN Red List. However, the Canadian Committee on the Status of Endangered Wildlife assessed eastern populations and considers this species as “Special concern.” The provinces of Newfoundland and Labrador list eastern populations of Barrow’s goldeneyes as “Vulnerable”.

Populations of Barrow’s goldeneyes seem to be relatively stable. There are several threats that are effecting Barrow’s goldeneyes' survival and reproductive success. Commercial forestry is likely a significant threat to Barrow’s goldeneyes but the most dramatic impact on their survival is a loss of habitat. Direct threats include destruction of nests during harvest operations and a reduced number of suitable potential nest sites. Hunting also poses a large threat to Barrow’s goldeneyes. Increased disturbance from hunters can have detrimental consequences if left unregulated. Additional threats include acid rain, oil spill contamination, human disturbance, and degradation of food resources from oil exploration.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Michael Kulinski (author), Northern Michigan University, Alec Lindsay (editor), Northern Michigan University, Leila Siciliano Martina (editor), Animal Diversity Web Staff.

References

Ballweber, L. 2014. Waterfowl parasites. Seminars in Avian and Exotic Pet Medicine , 13/4: 197–205.

Beauchamp, G. 1992. Diving Behavior in Surf Scoters and Barrow's Goldeneyes. The Auk , Vol. 109, No. 4: 819-827. Accessed January 21, 2014 at http://www.jstor.org/stable/4088156 .

Carney, S. 1992. Species, age and sex identification of ducks using wing plumage . Washington, DC Jamestown, ND: US Department of the Interior, US Fish and Wildlife Service. Accessed January 22, 2014 at http://www4.ncsu.edu/~csdepern/documents/WaterfowlWings.pdf .

Dunn, J., J. Alderfer. 2011. National Geographic field Guide to the birds of North America . Washington, DC: Random House Inc.

Eadie, J., J. Savard, M. Mallory. 2014. "Barrow's Goldeneye ( Bucephala islandica )" (On-line). The Birds of North America Online. Accessed January 22, 2014 at http://bna.birds.cornell.edu/bna/species/548/articles/introduction .

Evans, M., D. Lank, W. Boyd, C. Fred. 2002. A Comparison of the Characteristics and Fate of Barrow's Goldeneye and Bufflehead Nests in Nest Boxes and Natural Cavities. The Condor , 116/1: 610-619. Accessed March 16, 2014 at http://dx.doi.org/10.1650/0010-5422(2002)104[0610:ACOTCA]2.0.CO;2 .

Gardarsson, A. 1978. Distribution and numbers of the Barrow’s Goldeneye ( Bucephala islandica ) in Iceland. Natturufraedingurinn , 48: 162-191.

Garrot, d. 2003. "Sea Duck Information Series" (On-line). http://www.seaduckjv.org/ . Accessed January 22, 2014 at http://seaduckjv.org/infoseries/bago_sppfactsheet.pdf .

Lavers, J., J. Thompson, C. Paszkowski, . Ankney. 2006. Variation in Size and Composition of Bufflehead ( Bucephala albeola ) and Barrow's Goldeneye ( Bucephala islandica ) Eggs. The Wilson Journal of Ornithology , Vol. 118, No. 2: 173-177. Accessed January 22, 2014 at http://www.jstor.org/stable/20455856 .

Robert, M., R. Benoit, J. Savard. 2002. Relationship among Breeding, Molting, and Wintering Areas of Male Barrow's Goldeneyes ( Bucephala islandica ) in Eastern North America. The Auk , 119: 676-684.

Robert, M., B. Drolet, J. Savard. 2008. Habitat Features Associated with Barrow's Goldeneye Breeding in Eastern Canada. The Wilson Journal of Ornithology , Vol. 120, No. 2: 320-330. Accessed January 21, 2014 at http://www.jstor.org/stable/20456149 .

Robert, M., M. Vaillancourt, P. Drapeau. 2010. Characteristics of nest cavities of Barrow's Goldeneyes in eastern Canada. Journal of Field Ornithology , Vol. 81, No. 3: 287-293. Accessed January 21, 2014 at http://www.jstor.org/stable/3676460 .

Savard, J. 1986. Polygyny in Barrow's Goldeneye. The Condor , Vol. 88, No. 2: pp. 250-252. Accessed January 21, 2014 at http://www.jstor.org/stable/1368925 .

Savard, J. 1985. Evidence of Long-Term Pair Bonds in Barrow's Goldeneye ( Bucephala islandica ). The Auk , Vol. 102, No. 2: 389-391. Accessed January 21, 2014 at http://www.jstor.org/stable/4086785 .

Vermeer, K. 1982. Food and distribution of three Bucephala species in British Columbia waters. Wildfowl , 33/33: 22-30. Accessed March 18, 2014 at http://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/646 .

van de Wetering, D., F. Cooke. 2000. Body weight and feather growth of male Barrow's Goldeneye during wing molt. The Condor , Vol. 102, No. 1: 228-231. Accessed January 21, 2014 at http://www.bioone.org/doi/full/10.1650/0010-5422%282000%29102%5B0228%3ABWAFGO %5D2.0.CO%3B2 .

2014. "BirdLife International" (On-line). IUCN Red List of Threatened Species. Accessed April 21, 2014 at http://www.birdlife.org .

United States Geological Survey. Longevity Records Of North American Birds. 2013.3. Patuxent Wildlife Research Center: Jo Anna, Lutmerding. 2013. Accessed April 21, 2014 at http://www.pwrc.usgs.gov/ .