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Seabird Species

Sabine's Gull

Sabine's Gull Larus sabini

Les Underhill and John Cooper
Animal Demography Unit

  Sabine's Gull
Photo Les Underhill
Adult Sabine's Gull on its nest in an area of polygon tundra about 40 inland near Lake Pronchishcheva, eastern Taimyr Peninsula, Siberia, Russia, July 1991. There were four nests in a loose colony

Breeding distribution

Sabine's Gull Larus sabini has a fragmented breeding distribution on the tundra. It breeds in Asia, North America and Greenland. In Europe, it occurs only on Svalbard, where about five pairs breed.

One of the breeding areas of Sabine's Gulls in Asia is in the Taimyr Peninsula in Siberia, where it nests in small colonies along the coast and along lakes and river floodplains, mainly on the eastern and northern parts of Taimyr. The largest colony found in Taimyr numbered about 30 pairs.

Migrations

The migratory movements of Sabine's Gulls are relatively well understood. This information is derived from observations, rather than from bird ringing studies. Very few have been ringed, and there are no ring recoveries.

The Sabine's Gulls that breed in Siberia migrate eastwards along the Arctic Ocean, with failed breeders starting in July, and all birds having left their breeding areas by August. They pass into the Pacific Ocean through the Bering Strait and migrate offshore of the west coast of North America. Peak passage past California is in September. Records off Columbia and Ecuador are mainly in September-November. Sabine's Gulls breeding in Alaska follow this route too. The main non-breeding area is off South America, in the cold water upwellings of the Peru Current, mainly between 5S and 20S, off Peru and northern Chile. One observer reported counting 1000 gulls in two hours in mid-December while travelling about 20 km offshore at about 16S. Northwards migration starts in about April, and breeding starts on the tundra in mid-June.

  Nest of Sabine's Gull
Photo Les Underhill
Nest of Sabine's Gull, Lake Pronchishcheva, Siberia, 26 June 1991. By 2 July, the nest contained three eggs

Sabine's Gulls breeding in eastern Canada and Greenland leave in August and early September, fly southeastward across the Atlantic Ocean in the direction of the Iberian Peninsula, and then head south offshore of the west coast of Africa. Southward passage past West Africa occurs from late August into November. The non-breeding area of most of these birds lies in the Benguela Upwelling System, between 18S and 35S, off the coast of Namibia and South Africa. East of Cape Agulhas it becomes increasingly scarce, and is a vagrant off Mozambique. Vagrants occur as far south as the Prince Edward Islands. It occurs in continental waters out to the shelf edge, from 2 km to 150 km offshore. Numbers build up here from late September onwards. Departure is mainly by the end of April, with smaller numbers in May, and a few stragglers overwintering. The main northward passage past West Africa is in the first half of May. Arrival on the breeding grounds in Greenland and eastern Canada is in June.

One aspect of the migration of Sabine's Gulls which is not clear is the position of the migratory divide in North America. Alaskan birds migrate to South America, eastern Canadian birds to southern Africa. Some where in northern Canada there must be a line between birds which fly west after breeding, join the Siberian-Alaskan birds and migrate to South America and those which fly east, join the birds breeding in western Canadian and Greenland, and migrate to southern Africa.

Status in southern Africa

The first record of Sabine's Gulls off southern Africa was made on 29 November 1936, when five were seen in Algoa Bay. From then until 1963, there were seven records: three in Algoa Bay, 20 March 1941; one off St Helena Bay, 2 February 1953; about 20 between Cape Town and Dassen Island, January 1954; Cape Town Harbour, 29 December 1957; one specimen collected near Slang Bay, Port Elizabeth, 26 February 1958; two specimens collected off Port Alfred, 6 February 1959; one specimen colelcted near Bird Island (Algoa Bay), 7 December 1960; four south of Cape Agulhas, 26 March 1961; six 8 km from Cape Point, 3 February 1962; about 50 about 30 km north of Luderitz and 1.5 km offshore, 13 February 1962; two between Cape Town Harbour and Robben Island, 7 February 1963.

From 1964 onwards, the number of records proliferated, and several sightings were made each year. Peter Zoutendyk was an oceanographer who documented the occurrence of the populations of Sabine's Gulls off the Cape Peninsula during regular cruises between 1962 and 1967. Peak counts in successive summers were 31 in 1963/64, 78 in 1964/65, 300 in 1965/66, and 140 in 1966/67.

Kurt Lambert, a German ornithologist, had several long periods at sea off Namibia between 1966 and 1968. He saw Sabine's Gulls in small flocks from Cape Frio southwards; this is roughly the northern limit of the Benguela Upwelling System, at 18S. The largest flocks he saw were at the southern limit of his travels, near Luderitz; he counted 222 gulls offshore on 9 February 1967, 47 on 23 February 1967, and 92 the next day. He estimated that 5-10% of the birds he saw were first-years.

  Washed up Sabine's Gull
Photo Beau Rowlands
This Sabine's Gull was found by Beau Rowlands on Milnerton beach
on 13 January 1999.

By the late 1970s, flocks exceeding 1000 birds were occasionally being recorded. The following report was published in Promerops, the newsletter of the Cape Bird Club. During four visits watching seabirds at the Moullie Point sewage outlet in December 1977, Brian Cochrane observed a remarkable increase in the numbers of Sabine's Gulls. On 4 December one was seen; by 10 December there were about 50, and on the next day there were about 500. On 16 December he counted 2 500 along a short stretch of the shore. He reported that they "were feeding right up to the sea wall and not only the beautiful plumage and forked tail were visible but also the yellow tip to the otherwise short black bill. Less than 1% of the birds were in juvenile plumage." When he returned on 28 January 1978, no Sabine's Gulls were present, and on 12 February there were 16 birds floating near the sewage outlet. (Promerops (1978) 133: 4) This sewage outlet close to the shore no longer exists; processed effluent is now discharged far offshore.

In January and February 1996, exceptionally large flocks of Sabine's Gulls were present around Dassen Island, especially in House Bay, on the island's northern shore. The peak count was made on 14 February, when 4400 Sabine's Gulls were counted; the flock extended along the eastern and southern shores of the island.

During March 2001, thousands of Sabine's Gulls were present in Table Bay, and especially offshore of the eastern shore of Robben Island. A large proportion of these birds were conspicuously first-year birds. This seems to be the first occasion on which first-year birds were present in large numbers; previous observations suggested that less than 1% of the populations off the Cape Peninsula were first years.

Key references

  • Calf KM, Underhill LG 2002. Robben Island - highlights of 2001. Promerops 250: 17-18.
  • Cochrane B 1978. Sabine's Gull. Promerops 133: 4.
  • Lambert K 1967. [Observations on the migration and winter quarters of Sabine's Gull (Xema sabini) in the eastern Atlantic.] Vogelwarte 24: 99-106. (in German)
  • Lambert K 1969. [Sabine's Gull (Xema sabini) seen along the coasts of Namibia and South Africa in April-May 1968.] Vogelwarte 25: 49-52. (in German)
  • Liversidge R, Courtinay-Latimer M 1963. Sabine's Gull in South Africa. Annals of the Cape Provincial Museums (Natural History) 3; 57-60.
  • Morgan K, Wheeler P 1958. Sabine's Gull Xema sabini in Cape Town docks. Ostrich 29: 90.
  • Scharffetter F 1982. [Observations on winter quarters of Sabine's Gull (Xema sabini).] Vogelwarte 31: 463-465.
  • Whittington PA, Wolfaardt AC 1999. The avifauna of Dassen Island. Bird Numbers 8(2): 8-11.
  • Zoutendyk P 1965. The occurrence of Xema sabini off the coast of southern Africa. Ostrich 36: 15-16.
  • Zoutendyk P 1968. The occurrence of Sabine's Gull Xema sabini off the Cape Peninsula. Ostrich 39: 9-11.