Rosss Gull

Rosss Gull

Summary:

Profile Rosss Gull     Literature page Rosss

[order] Charadriiformes | [family] Laridae | [latin] Rhodostethia rosea | [UK] Rosss Gull | [FR] Mouette de Ross | [DE] Rosenmöwe | [ES] Gaviota de Ross | [IT] Gabbiano di Ross | [NL] Ross-Meeuw

Ross-Meeuw determination

copyright: I. Fulton

A small gull, with a tiny, dark bill, pale gray upperparts, and underparts washed with pink in adults. In flight, the long, wedge-shaped tail and prominent white trailing edge of the wing are evident; the underwing usually appears darker than the upperwing.
In alternate plumage, the pinkish cast to the plumage and black ring around the head are diagnostic. In basic plumage, note the evenly gray wings on both the upper and under surfaces and the wedge-shaped tail. In first-winter plumage the wedge-shaped tail is diagostic as is the small bill.

Breeding mainly on borderline between low Arctic and subarctic, extending even into boreal taiga zone in northern Siberia. Melting snow on tundra underlain by permafrost creates a muddy boggy terrain interspersed with countless shallow pools, which are dotted with sedge and moss, and with small low islets, partly within zone of thickets of grey alder and willows, but partly on open tundra, lying some way in from principal river channels. Nests placed on wet spots near water, in association with Arctic Tern, Spotted Redshank, Ruff, and other not exclusively arctic species.

Rhodostethia rosea breeds mostly in the tundra of Siberia and north-eastern Canada,
with one or two pairs breeding within Europe in Greenland. This tiny European
breeding population was stable between 1970-1990, but its trend during 1990-2000
was unknown. Although the size of the European population renders it susceptible
to the risks affecting small populations, it is marginal to a much a larger non-European
population.

Their diet mostly consists of marine crustacea, other plankton animals and small fish. Inland, during nesting season, they become mostly insectivorous.


This species has a large range, with an estimated global breeding Extent of Occurrence of 50,000-100,000 km². It has a large global population estimated to be 25,000-100,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]


Breeding sites discovered in Siberia were surrounded by vegetation that included bushes and hardwood trees and occasionally
coniferous trees and resembled the habitat near the Canadian mainland breeding site of Churchill, Manitoba. The habitat on Prince Charles Island is more truly arctic and probably more closely resembles the other breeding localities found in the High Arctic, elsewhere referred to as marshy wetlands in subalpine and boreal tracts. Pairs of Ross’s gulls arrive
together at breeding sites. Hence, paired Ross’s gulls may remain together during the non-breeding season, or pair bonds could also be established on the winter quarters. Ross’s Gulls nest is in loose colonies, on low islets or marshes near extensive open water in early spring. It may be a well-formed scrape or a barely perceptible depression in gravel or moss or other vegetation, often only a few inches above the water. One to three eggs are laid and incubated by both parents.

Migratory. Main wintering areas northern Bering Sea and Sea of Okhotsk; some birds move south as far as Kuril islands. Most high-latitude marine records north of Europe date from early period of polar exploration by ship, and therefore relate to late summer and autumn only. Breeding grounds in north-east Siberia reoccupied late May to early June, according to time of thaw; mass departures occur in second half of July.

Specification

  1. Measurements
  2. spanwidth min.: 90 cm
  3. spanwidth max.: 100 cm
  4. size min.: 29 cm
  5. size max.: 31 cm
  6. Breeding
  7. incubation min.: 0 days
  8. incubation max.: 0 days
  9. fledging min.: 0 days
  10. fledging max.: 0 days
  11. broods 0
  12. eggs min.: 0
  13. eggs max.: 0
  14. Conservation Status
  15. Ross-Meeuw status Least Concern

Subspecies

  1. Leucophaeus rosea
  2. Rhodostethia rosea
  3. EU, NA n coasts
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