Justification This species has declined rapidly in parts of its range, but its status in other areas is poorly known. A number of factors are likely to be contributing to declines, including climate change, pollution and increasing human intrusion or hunting within breeding areas. It is currently considered Near Threatened; but further surveys are required in order to clarify the true magnitude of declines.

Family/Sub-family Laridae

Species name author (Phipps, 1774)

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Cramp and Simmons (1977-1994), Sibley and Monroe (1990, 1993)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

15,000 - 25,000

decreasing

397,000 km²

No

Range & population Pagophila eburnea has a near-circumpolar distribution in the Arctic seas and pack-ice, breeding from north Canada through Greenland (to Denmark), Svalbard (Svalbard and Jan Meyan Islands (to Norway)) and islands off northern Russia. The Russian population is estimated to number in the range of 14,500-22,000 individuals, with recent surveys giving estimates of including 1,500-3,000 breeding pairs on Franz-Josef Land (European Russia), 5,000-6,000 pairs on Severnaya Zemlya; and 1,500-3,000 pairs in the rest of the Kara Sea Islands²³. Other populations include 500-700 individuals in northeast Canada^13,19, 500-1,000 in Greenland¹³, and 350-500 pairs in Svalbard^13,24. Given these totals, the global population is perhaps best placed in the band 15,000-25,000 individuals. The population is possibly larger: extrapolations based on aerial estimates suggested up to 35,000+ between Canada and Greenland in 1978-1979 ¹⁶. The Spitsbergen population is probably decreasing¹¹, and breeding has apparently recently ceased on Victoria Island in Russia²³. Other Russian populations are apparently stable, although interannual fluctuations complicate the calculation of trend estimates. Recent surveys have revealed a drastic decline in Canadian populations, falling from 2,400 birds in 1987 to 500-700 birds in 2002-2003¹³, representing an 80% decline in that period across the Canadian breeding range in all three known nesting habitat types¹⁴. Birds have disappeared from 13 known and three suspected breeding colony sites.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: This species is migratory¹⁸. It breeds between late-June and August (although most pairs do not lay until early-July, and some pairs may not breed if food conditions are unfavourable) in colonies of 5-60 pairs (rarely more than 100 pairs)⁶. It departs from the breeding grounds between August and October, returning late-February to early-June¹⁸. Outside of the breeding season the species is weakly gregarious, occurring singly or in flocks of up to 20 individuals¹⁷. Larger numbers also gather in the spring at hooded seal Pagophilus groenlandicus whelping sites, where they feed on carrion and discarded placentae⁶. The species also regularly follows polar bears Thalarctos maritimus to feed on scraps from their kill⁶. Habitat Breeding It breeds in the high Arctic north of the July 5^oC isotherm¹⁷ on coastal or inland cliffs^{6, 17} up to 300 m high¹⁷, on broken ice-fields or on bare, level shorelines with low rocks^{6, 17}. Non-breeding Outside of the breeding season it associates with the edges of pack-ice, showing a preference for areas with 70-90% ice cover⁶. Diet Its diet consists predominantly of fish, shrimps, shellfish, algae and carrion (e.g. seal placentae)⁶. Breeding site The nest is constructed of moss, straw and other debris on a snow-free area of rock⁶. Nest sites include broad upper ledges of steep, inaccessible coastal or inland cliffs^{6, 17} up to 300 m high¹⁷, broken ice-fields and bare, level shorelines with low rocks^{6, 17}. On cliffs, pairs usually nest within 10 m of the top in small colonies with inter-nest distances of 1-20 m⁶.

Threats The species is thought to be declining due to changes in conditions on its staging or wintering grounds (e.g. more severe winters, changing sea-ice distribution and thickness)¹⁹. The species is hunted¹⁹. Potential causes of the decline identified in Canada include illegal hunting²⁰, oiling at sea, disturbance of colonies due to escalating diamond exploration and/or increased nest predation, and toxic pollutants that bioaccumulate at high trophic levels²¹. For example, concentrations of total mercury in eggs of Ivory Gulls collected from Seymour Island, Canada, have steadily increased since 1976 to levels which are now among the highest measured in seabirds²¹, which may have had a long-term effect on breeding productivity²².

Conservation measures proposed Monitor population trends throughout the range, with particular emphasis on determining rates of decline in main breeding areas. Research the magnitude of threats facing all populations. Protect colonies from mining action.

References 1. Volkov and de Korte (1996). 2. Dement'ev (1951). 3. Bangjord et al. (1994). 4. Thomas and MacDonald (1987). 5. Evans (1984). 6. del Hoyo et al. (1996). 7. Tucker and Heath (1994). 8. Krajick (2003). 9. Mehlum and Bakken (1994). 10. Mehlum and Fjeld (1987). 11. A. Volkov in litt. (2003). 12. Vuilleumier (1995). 13. Hess (2004). 14. Gilchrist and Mallory (2005). 15. BirdLife International (2004). 16. Orr and Parsons (1982). 17. Snow and Perrins (1998). 18. Olsen and Larsson (2003). 19. Gilchrist and Mallory (2005). 20. Stenhouse et al. (2004). 21. Braune et al. (2006). 22. C. Miljeteig in litt. (2007). 23. M. Gavrilo in litt. (2007). 24. H. Strom in litt. (2007).

Further web sources of information

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Text account compilers Stuart Butchart (BirdLife International), Jonathan Ekstrom (BirdLife International), Sally Fisher (BirdLife International), Matt Harding (BirdLife International), Lucy Malpas (BirdLife International)

Contributors Maria Gavrilo (Arctic and Antarctic Research Institute), C Miljeteig, Iain Stenhouse (Alaska Audubon Society), Hallvard Strom (Norwegian Polar Institute), A. Volkov

IUCN Red List evaluators Ian Burfield (BirdLife International - European Division), Stuart Butchart (BirdLife International), James Gilroy (BirdLife International), Rob Pople (BirdLife International - European Division), Alison Stattersfield (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Pagophila eburnea. Downloaded from http://www.birdlife.org on 9/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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