Phalaropus lobatusnorthern phalarope(Also: red-necked phalarope)

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Geographic Range

The red-necked phalarope (Phalaropus lobatus) is the most abundant and widely distributed species of the genus Phalaropus. It has a circumpolar distribution and is found in both boreal and tundra zones between 60 and 70 degrees latitude. These phalaropes can be found in coastal regions of the Arctic Ocean, south to the Aleutians and Northwest to Britain. In the winter, the red-necked phalarope spends most of its time on the ocean. During this non-breeding season, phalaropes can be found off central-west South America, in the Arabian Sea and from central Indonesia to western Melanesia.

(del Hoyo et al 1996) (Cameron and Harrison 1978)

Habitat

During the breeding season, the red-necked phalaropes inhabit the tundra/forest tundra areas near lakes or wetlands with marshy riparian zones that include an abundance of grasses, moss, and sedges. They have also been found in sparsely vegetated lava deserts in Iceland, coastal moorlands, on floodplains of large rivers, as well as bogs. During migration these birds will find saline lakes to use, and the winter season is spent at sea in upwelling zones and ocean slicks.

(del Hoyo et al 1996)

  • Aquatic Biomes
  • lakes and ponds

Physical Description

This species of phalarope is the smallest of the genus Phalaropus, with a length of 18-19 cm, and a wingspan of 31-34 cm. The red-necked phalarope exhibits reverse sexual dimorphism, meaning the females are more brightly colored in their breeding plumage than the males. The female has a grey head, neck, and sides of the breast, with a chestnut colored collar and a white throat; the wings are buff colored, there is a small white band above the eye, and the stomach is completely white. The males are much duller in color as they have a brown head, neck, and upperparts. The non-breeding plumage of the phalarope includes dull grey upperparts, and the head is mainly white with a black patch through and behind the eye. The juveniles have brown head, neck, upperparts and eyepatches. Their breast appears to be "washed" buff color, and the rest of the underparts are white.

(del Hoyo et al 1996)

  • Range mass
    20 to 48 g
    0.70 to 1.69 oz

Reproduction

In general, the red-necked phalarope employs a monogamous mating system. However, when males are in excess, the female will mate with many males (polyandrous mating system). The P. lobatus females will arrive at the Artic breeding grounds in May to mid-June before the males and will compete among themselves and display in small parties. The females will often seek and defend a male mate. Once they have copulated, both will build one or more nests, and the female will lay the eggs. Their nest consists of a scrape on the ground that is lined with stems and leaves, often in close proximity to water.

The female will lay 4 (occasionally 3) eggs at intervals of 24-30 hours. If the relationship is monogamous the eggs are singly brooded, but if the mating system is polyandrous, the eggs are double-brooded. The male incubates the eggs himself, starting with the fourth egg laid, and tends to the chicks once hatched. Just before his incubation begins, the male will molt the feathers from his abdomen to produce two brood patches. These patches will become engorged with blood, and act to keep the eggs warm while he sits on them.

Once the chicks hatch, the females will leave for their winter breeding grounds, which is as early as the end of June. The males will remain for another two weeks, after which they too will leave. The chicks fledge at 18-21 days and will start their migration in August. The 1 year old chick will breed in its first season, and can live up to 5 years.

(del Hoyo et al 1996, Terres 1980)

Lifespan/Longevity

Behavior

The red-necked phalarope is generally solitary on its summer breeding grounds unless habitat is restricted, and then it will remain loosely colonial. During migration to and from the breeding grounds, these birds are highly gregarious, as well as in the winter, where phalaropes can be found in massive groups. This may include saline lakes, areas of oceanic upwelling where high stocks of zooplankton can be found, as well as areas at sea with surface swarms of euphausiid shrimps.

The female phalarope is generally non-territorial, with the exception of defending the actual nest or mate. The females will also engage in aerial chases, usually involving numerous females chasing a male. When copulation occurs in P. lobatus, the female will indicate her readiness by uttering a low note while she is swimming on the water. Upon hearing this, the male will rise out of the water and hover above the female momentarily. When he descends to her back to copulate, he actually pushes her part way under the water.

(del Hoyo et al 1996, Campbell and Lack 1985)

Communication and Perception

Food Habits

In freshwater environments during the breeding season, the red-necked phalarope eats aquatic insect larvae (primarily mosquitoes), as well as dipteran flies, beetles, caddisflies, ants, annelid worms, snails, as well as some seeds. When at sea during the non-breeding period, the birds will feed on zooplankton, including euphausiids and calanoid copepods as well as crustaceans, tiny fish, and even jellyfish. Red-necked phalaropes particularily like ocean slicks and areas where there is an accumulation of organisms because it usually means an abundance of food.

Birds in the Phalaropus genus forage by wading, walking, and swimming. They use their needle-like bill and slender neck to peck at the prey on the surface or below the water as well as pluck flying insects out of the air. In picking the food items out of the water, the phalarope will use the water surface tension to transport the prey from the bill to their mouth.

One of the most unique features of members of this genus of birds is the method by which they capture their food. The red-necked phalarope will stir up its food using the rapid swimming movements of its feet, all the while spinning their bodies round and round on the water at many revolutions per minute. As they turn, they make quick jabbing motions to pick up the food they have brought to the surface. Occasionally you may see the phalarope up-end (like a dabbling duck) to retrieve food beneath the water, but this is not as common.

(del Hoyo et al 1996, Campbell and Lack 1985, Cameron and Harrison 1978)

Economic Importance for Humans: Positive

The red-necked phalarope is of little economic importance to humans. Probably the most economically significant feature of the phalarope is that it will eat the larvae of mosquitoes. As mosquitoes are a serious pest in certain locations around the world, the presence of the red-necked phalarope may have a small impact on these populations. However, because their diet is much more diverse than just mosquitoes, and they spend only a short time on wetlands and lakes in close proximity to people, they have little impact.

Conservation Status

The red-necked phalarope is not globally threatened. The total breeding populations of Eurasia and the Nearctic exceed one million birds. The numbers in the Bay of Fundy are decreasing, but the cause is unknown and it has yet to affect their status overall.

(del Hoyo et al 1996)

Other Comments

The red-necked phalarope was formerly known as the Northern phalarope.

Phalaropes have short webs between the bases of their front toes (semi-palmated) and all four toes are expanded and have a fringe of scales, much like the lobed feet of a coot. In fact, the name 'phalarope' comes from the Greek phalaris, meaning coot, and pous, meaning foot, hence "coot foot".

Red-necked phalaropes are the only true oceanic shorebirds. Phalaropus lobatus form close-knit flocks that congregate at sea, chiefly in coastal or off-shore waters, and quickly lose their nuptial plumage. Due to the fact that they spend much of the year on the ocean, they have salt glands and a dense layer of down that provides a raft of trapped air. This provides waterproofing, and also allows them to float high (cork-like) on the water. However, this additional buoyancy makes submerging difficult, so these birds do not dive. The phalarope is also able to rest and sleep while they are in this floating position. Because the phalarope is so light, these birds are at risk of being caught in gales while water-borne, so they tend to be driven leeward.

The male alone broods and tends the chicks because their development depends on the typically female hormone prolactin, of which the male secretes more than the female. In addition, the bright plumage of the females is regulated by the hormone testosterone, which is normally a male hormone.

Graul et al (1977) formulated a reason for the evolution of polyandry in the red-necked phalaropes. They believe that because the food resources are often sparse, and the breeding season is so short, the female will not have enough energy to both produce and incubate the eggs. Because the male can independently incubate and hatch the eggs, the female will likely survive, and the population will remain viable. Graul also states that in a spring where food resources are abundant, the female is able to produce two batches of eggs and recruit two males to incubate them, thereby increasing her reproductive success.

(del Hoyo et al 1996, Campbell and Lack 1985, Terres 1980, Cameron and Harrison 1978, Graul et al. 1977)

Contributors

Delaney Anderson (author), University of Alberta, Cindy Paszkowski (editor), University of Alberta.

Glossary

Arctic Ocean

the body of water between Europe, Asia, and North America which occurs mostly north of the Arctic circle.

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

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Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

holarctic

a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.

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Found in northern North America and northern Europe or Asia.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

visual

uses sight to communicate

References

Cameron, A., C. Harrison. 1978. Bird Families of the World. Oxford, England: Elsevier-Phaidon.

Campbell, B., E. Lack. 1985. A Dictionary of Birds. Vermillion, S.D.: Butco Books.

Fisher, C., J. Acorn. 1998. Birds of Alberta. Edmonton: Lone Pine Publishing.

Graul, W.D, D., Mock, D.W.. 1977. The evolution of avian polyandry. American Naturalist, 111: 812-816.

Terres, J. 1980. The Audubon Society Encyclopedia of North American Birds. New York: Knopf.

del Hoyo, J., A. Elliott, J. Sargatal. 1996. Handbook of the Birds of the World vol 3. Barcelona: Lynx Edicions.