Ivory Gull

The Ivory Gull (Pagophila eburnea) is a solely Arctic bird and rarely leaves the Arctic region to southern shores. This pure-white seabird is a characteristic species of the High Arctic Sea and it stays at the edge of the Arctic sea ice all year round. It is an uncommon bird, and it has a patchy distribution around the high Arctic. Interestingly, the breeding colonies are restricted to the Eastern High Arctic only and it does not nest east of Taimyr and west of Devon Island (Figure 1). Its total population is estimated at 12,000-14,000 pairs and possibly stable overall with locally severe declines. Severe declines of the highly specialised Arctic seabird have been observed in Canada, but possibly also in Svalbard. The population is stable or even increasing in Northern and Eastern Greenland and it remains strong without showing any clear trend in the remaining stronghold in Russia according to the latest surveys.

Inuit in Grise Fiord, Arctic Bay and Resolute Bay in Canada have first reported a decline in the Ivory Gull over the last 25 years. In 2003 biologists in Arctic Canada documented Inuit local ecological knowledge about the gulls and each year from 2002 to 2006 they conducted surveys over the breeding range in Canada. They concluded that the Canadian population of Ivory Gulls has declined by 80% since the early 1980s, with a total population count in 2006 of only 245 birds. The 2006 season appeared to be more favourable with a slight increase and almost 600 birds at newly discovered colonies.

This alarming drop in numbers has raised concerns in other parts of the Arctic. The colonies in Greenland are the least known. Recent observations of new colonies indicate huge shifts or even a potential increase. Surveys are planned for 2007 and the International Polar Year 2007/08. It is estimated that 80% of the remaining world population of Ivory Gulls now breed in the high Arctic islands of Svalbard, Frantz-Josef Land and Severnaya Zemlya in Russia. Alerted by the Canadian results a joint Russian and Norwegian initiative has been launched in the summer of 2006 to assess the Ivory Gull colonies in the Barents and Kara Seas. The results are surprising and promising at the same time. Based on the 2006 expedition and previous surveys the population in Svalbard is now estimated at 350–500 breeding pairs, which still indicates a continued decrease, although not all potential colonies were monitored. The survey in Russia, covering a third of the known range, counted a total of 3,000 breeding pairs at 7 colonies only, confirming the previous estimate of 10,000 pairs for Russia but also dramatic shifts between colonies.  The biggest colony ever surveyed numbered 1,500 pairs on Domashniy Island N of Taimyr. Many former sites were abandoned and new sites colonized, reflecting the shift between colonies and the fluctuations within years over a 70-year period.

The Ivory Gull lives at the edge of the sea ice, feeding on fish, small crustaceans and carcasses of marine mammals. Because of its nutritional choices and intimate association with sea ice the species is very sensitive to climatic changes and environmental pollutants. Breeding success has been closely related to the sea ice conditions and it has been noticed that entire colonies have suddenly been abandoned, possibly in response to changing feeding conditions. Changes in sea ice distribution might be responsible for the shifts in distribution and the interannual variation between the sites and years. Ivory Gulls are hunted in northwest Greenland during migration and this may be affecting Canadian populations. Disturbance from exploration for diamonds in part of the gulls’ range may also be contributing to the decline. Toxic substances could play a role, as high levels of mercury have been measured in Canadian Ivory Gull eggs. Russian eggs in 2006 showed extremely high levels of DDT and PCBs but low contents of mercury. The stable situation in the main colonies in Russia might simply reflect a favourable year among the highly fluctuating population. But it is for certain that the huge dependency on the sea ice and the high level exposure to different types of pollutants leaves the Arctic sea birds highly vulnerable to a rapidly changing environment. The recent effort in research and monitoring improved our understanding of this mysterious bird but still offers a lot of questions to be answered. The Inuit in Canada regard the species with great affection and consider its decline as an ominous indicator of a greater systematic ill in their Arctic environment. International efforts are required to continue to monitor the Ivory Gull as a sensitive indicator for Arctic ecosystem health.

Sources:

Bakken V., Tertitski, G. The Ivory Gull // Anker-Nielson, T., V. Bakken, H. Strøm, A.N. Golovkin, V.V. Bianki & I.P. Tatarinkova (2000): The status of marine breeding birds in the Barents Sea region. Norsk Polarinstitutt Rapportserie Nr. 113

Gavrilo, M.V. & Strøm, H. 2004. The ivory gull populations in the Russian and Norwegian Arctic: call for joint effort to evaluate current status. Complex investigations of Spitzbergen nature. Iss. 4. Apatity: Publ. KSC. RAS. Pp. 240 – 247. (In Russian with English summary).

Gavrilo M.V., Volkov A.E., Volkova E.V.,Lokhov A.Yu., Prodan O.L. Survey of Ivory Gull colonies in the Russian Arctic 2006 // Strøm H., Gavrilo M.V. (eds.) Survey of ivory gull colonies in the Norwegian and Russian Arctic 2006. - NP Report series. – Tromso, 2007 (in press)

Gavrilo M.V., Strøm H., Volkov A.E. Population status of Ivory Gull populations in Svalbard and Western Russian Arctic: first results of joint Russian-Norwegian research project // Complex investigations of Spitzbergen nature. Iss. 7. Apatity: Publ. KSC RAS, 2007. (submit.) In Russian with extended English summary

Gilchrist, H.G. and Mallory, M.L. 2005. Declines in abundance and distribution of the Ivory Gull
(Pagophila eburnea) in Arctic Canada. Biological Conservation 121: 303-309.

Mallory, M.L., Gilchrist, H.G., Fontaine, A.J. and Akearok, J.A. 2003. Local ecological knowledge
of Ivory Gull declines in Arctic Canada. Arctic 56: 293-298.

Mallory, M. & G. Gilchrist 2006. Ivory Gull surveys in the High Arctic. Report 2006

Norsk-Russiske Miljøvernsamarbeidet (2005). Factsheet: Russian-Norwegian Seabird Collaboration. http://doksenter.svanhovd.no/faktaark/2005/Faktaark_Sjofugl_2005_ENG.pdf. accessed 12.12.2005

Stenhouse and others (2005) Unpublished COSEWIC Status report for the Committee of the status of endangered wildlife in Canada. 44p.

Volkov A.E., J. de Korte 1996):  Distribution and numbers of breeding Ivory Gulls Pagophila eburnea in Severnaya Zemlya, Russian Arctic. Polar Research 15 (1)11-21.

Volkov A.E., J. de Korte 2000:  Breeding ecology of the Ivory Gull (Pagophila eburnea) in Sedov Archipelago, Severnaya Zemlya. Pp. In Ebbinge B.S., Mazourov Yu.L. and Tomkovich P.S. (eds.): Heritage of the Russian Arctic. Research, conservation and international cooperation. Moscow, Ecopros Publishers.

Figure 1: Distribution of circumpolar Ivory Gull colonies (black dots)
 

We acknowledge the kind provision of information for this factsheet by the CBMP network, in particular Maria Gavrilo, Russia.