Ivory Gull


Ivory Gull
Ivory Gull
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
Genus: Pagophila
Kaup, 1829
Species: P. eburnea
Binomial name
Pagophila eburnea
(Phipps, 1774)
Synonyms
  • Larus eburneus Phipps, 1774
  • Pagophila alba Gunnerus

The Ivory Gull Pagophila eburnea is a small gull, the only species in its genus. It breeds in the high arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia.

Contents

Taxonomy

The Ivory Gull was initially described by Constantine Phipps, 2nd Baron Mulgrave in 1774 as Larus eburneus from a specimen collected on Spitsbergen.[1] Johann Jakob Kaup later recognized the unique traits of the Ivory Gull and gave it a monotypic genus, Pagophila, in 1829.[1] Johan Ernst Gunnerus later gave the species a new specific name, Pagophila alba.[1] Today some authors consider the Ivory Gull not deserving of its monotypic genus, instead to choosing to merge it, along with the other monotypic gulls, back into Larus.[1] However, most authors have not chosen to do so. The Ivory Gull has no subspecies.[1] No fossil members of this genus are known.[2]

This gull is traditionally believed to be most closely related to either the kittiwakes, Sabine's Gull, or Ross's Gull.[1] It differs anatomically from the other genera by having a relatively short tarsometatarsus, a narrower os pubis, and potentially more flexibility in skull kinetic structure.[1] Structurally, it is most similar to the kittiwakes; however, recent genetic analysis based on mtDNA sequences shows that Sabine's Gull is the Ivory Gull's closest relative, followed by the kittiwakes, with Ross's Gull and Swallow-tailed Gull sharing a clade with these species.[1] "Pagophila" is maintained as a unique genus because of the bird’s morphological, behavioral and ecological differences from these species.[1]

Description

This species is easy to identify. At 43 cm (17 in), it has a different, more pigeon-like shape than the Larus gulls, but the adult has completely white plumage, lacking the grey back of other gulls. The thick bill is blue with a yellow tip, and the legs are black. Its cry is a harsh eeeer. Young birds have a dusky face and variable amounts of black flecking in the wings and tail. The juveniles take two years to attain full adult plumage. There are no differences in appearance across the species’ geographic range.[1]

Distribution and habitat

A pure white Ivory Gull looks left over an icy sea.
An Ivory Gull wintering in the Bering Sea

In North America, it only breeds in the Canadian Arctic.[2] Seymour Island, Nunavut is home to the largest known breeding colony, while Ellesmere, Devon, Cornwallis, and north Baffin Islands are known locations of breeding colonies.[2] It is believed that there are other small breeding colonies of less than six birds that are still undiscovered.[2] There are no records of the Ivory Gull breeding in Alaska.[2]

During the winter, Ivory Gulls live near polynyas, or a large area of open water surrounded by sea ice.[2] North American birds, along with some from Greenland and Europe, winter along the 2000 km of ice edge stretching between 50° and 64° N from the Labrador Sea to Davis Strait that is bordered by Labrador and southwestern Greenland.[2] Wintering gulls are often seen on the eastern coasts of Newfoundland and Labrador and occasionally appear on the north shore of the Gulf of St. Lawrence and the interior of Labrador.[2] It also winters from October through June in the Bering Sea and Chukchi Seas.[2] It is most widespread throughout the polynyas and pack ice of the Bering Sea.[2] It is also vagrant throughout coastal Canada and the northeastern United States, though records of individuals as far south as California and Georgia have been reported, with most records from late November through early March.[2] Juveniles tend to wander further from the Arctic than adults.[2]

Ecology and behavior

It migrates only short distances south in autumn, most of the population wintering in northern latitudes at the edge of the pack ice, although some birds reach more temperate areas.

Diet

It takes fish and crustaceans, rodents, eggs and small chicks but is also an opportunist scavenger, often found on seal or porpoise corpses. It has been known to follow polar bears and other predators to feed on the remains of their kills.

Reproduction

Ivory Gull breeds on Arctic coasts and cliffs, laying one to three olive eggs in a ground nest lined with moss, lichens, or seaweed.

Gallery

References

  1. ^ a b c d e f g h i j Mallory, Mark L.; Iain J. Stenhouse, Grant Gilchrist, Gregory Robertson, J. Christopher Haney and Stewart D. Macdonald (2008). "Ivory Gull-Systematics". The Birds of North America Online. Cornell Lab of Ornithology. http://bna.birds.cornell.edu/bna/species/175/articles/systematics. Retrieved 2010-11-16. (subscription required)
  2. ^ a b c d e f g h i j k l Mallory, Mark L.; Iain J. Stenhouse, Grant Gilchrist, Gregory Robertson, J. Christopher Haney and Stewart D. Macdonald (2008). "Ivory Gull-Distribution". The Birds of North America Online. Cornell Lab of Ornithology. http://bna.birds.cornell.edu/bna/species/175/articles/distribution. Retrieved 2010-11-18.  (subscription required)
  • BirdLife International (2006). Pagophila eburnea. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 6 May 2006. Database entry includes a brief justification of why this species is near threatened
  • Seabirds by Harrison, ISBN 0-7470-1410-8
  • Bull, John; Farrand, Jr., John (April 1984). The Audubon Society Field Guide to North American Birds, Eastern Region. New York: Alfred A. Knopf. ISBN 0-394-41405-5. 

External links


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Look at other dictionaries:

  • Ivory gull — Ivory I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance… …   The Collaborative International Dictionary of English

  • ivory gull — noun white Arctic gull; migrates as far south as England and New Brunswick • Syn: ↑Pagophila eburnea • Hypernyms: ↑gull, ↑seagull, ↑sea gull • Member Holonyms: ↑Pagophila, ↑genu …   Useful english dictionary

  • ivory gull — snieginis kiras statusas T sritis zoologija | vardynas atitikmenys: lot. Larus eburnea; Pagophila eburnea angl. ivory gull vok. Elfenbeinmöwe, f rus. белая чайка, f pranc. mouette blanche, f ryšiai: platesnis terminas – snieginiai kirai …   Paukščių pavadinimų žodynas

  • ivory gull — a white, arctic gull, Pagophila eburnea. [1915 20] * * * …   Universalium

  • ivory gull — /aɪvəri ˈgʌl/ (say uyvuhree gul) noun a white arctic gull, Pagophila eburnea …   Australian English dictionary

  • Ivory — I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance constituting …   The Collaborative International Dictionary of English

  • Ivory black — Ivory I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance… …   The Collaborative International Dictionary of English

  • Ivory nut — Ivory I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance… …   The Collaborative International Dictionary of English

  • Ivory palm — Ivory I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance… …   The Collaborative International Dictionary of English

  • Ivory shell — Ivory I vo*ry ([imac] v[ o]*r[y^]), n.; pl. {Ivories}. [OE. ivori, F. ivoire, fr. L. eboreus made of ivory, fr. ebur, eboris, ivory, cf. Skr. ibha elephant. Cf. {Eburnean}.] [1913 Webster] 1. The hard, white, opaque, fine grained substance… …   The Collaborative International Dictionary of English