Last updated 4 May 2023

The ivory gull (Pagophila eburnea) is a high-Arctic species that is associated with ice-filled waters throughout the year. The species is found in north-eastern Canada, Greenland, Svalbard and Russia. The global breeding population is estimated at approximately 14,000 pairs. The species finds its food at the edges of drift ice, but it can also exploit the remains of polar bear prey. In Svalbard, the ivory gull nests in relatively small, scattered colonies, mainly in the east of Spitsbergen, on Barentsøya and on Nordaustlandet. Monitoring of the breeding population in Svalbard shows an annual decline of about 4% a year since monitoring started in 2009.

Ivory gulls breeding at Barentsøya, Svalbard. Photo: Vidar Bakken / Norwegian Polar Institute

What is being monitored?


The number of breeding pairs of ivory gulls in Svalbard

Development of the ivory gull population in 32 selected colonies, stated as a percentage of the average for the entire monitoring period. Monitoring of ivory gulls in Svalbard shows a decline in the breeding population of approximately 4% per year. The decline is seen in the context of the decline in the species’ primary habitat – sea ice.
(Cite these data: Norwegian Polar Institute (2023). The number of breeding pairs of ivory gulls in Svalbard. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: https://mosj.no/en/fauna/marine/ismaake.html)

Details on these data

Last updated4 May2023
Update intervalYearly
Next updateMay 2024
Commissioning organizationMinistry of Climate and Environment
Executive organizationNorwegian Polar Institute
Contact personHallvard Strøm

Method

A selection of 32 nesting colonies is visited late in the breeding season and early in the juvenile period, on foot or by snowmobile or helicopter. The number of occupied nests is recorded by two observers, as well as being documented with photographs. If work is done from a helicopter, the necessary distance from the colony is kept so that the birds do not leave the nests. The species can change nesting sites from year to year and it is therefore necessary to monitor a large number of colonies in order to discover whether the changes in numbers that are observed are due to movements between colonies.

Quality

The method is used in the four countries that have breeding populations of ivory gulls (Canada, Greenland, Norway and Russia).

Other metadata

All data is stored in the Norwegian Polar Institute’s seabird database. Aggregated data is also stored in the SEAPOP databases.

Status and trend

Monitoring of ivory gulls in Svalbard shows a decline in the breeding population of approximately 4% per year since 2009. This trend is considered to be serious, given the population size of the species and its limited global distribution. However, the time series is short (13 years) and we lack basic knowledge about the species’ biology. Caution should therefore be exercised in interpreting the data series. The decline in Svalbard is in line with similar trends in Canada and Greenland, where the species is also in decline.

Causal factors

The decline in the breeding population is seen in the context of an ongoing reduction in the species’ primary habitat – sea ice – and high levels of environmental toxins. However, the direct links are unclear. A decline of 70% has been documented in the Canadian breeding population. The species has also disappeared from the southernmost breeding grounds in Greenland.

Consequences

The ivory gull is, as the glaucous gull and the great skua, on of the top predators on Svalbard, and it has an important role in the ecosystem as a scavenger. The ivory gull contributes to the transport of nutrients from the marine environment to the terrestrial environment, they are fertilizing the areas under the breeding colonies with guano and remain of their prey. A decrease in the breeding population will therefore reduce this nutrient pump, which in turn will affect the terrestrial environment. The ivory gull is endemic to the Arctic, meaning it only occurs here (similar to, for example, polar bears and ringed seals).

About the monitoring

The ivory gull is monitored because the species is vulnerable to climate change and because such high levels of environmental toxins have been found that they could have an effect on the population size. The species is also classified as vulnerable in the Red List for Svalbard. The ivory gull is considered an ice-dependent species because it finds most of its food in the drift ice and remains in ice-filled waters throughout the year and throughout their life.

Places and areas

Monitoring is performed in 32 selected nesting colonies spread along the eastern side of Spitsbergen from Hornsund to Sorgfjorden, on Barentsøya  and on Nordaustlandet.

Relations to other monitoring

Monitoring programme

International environmental agreements

Voluntary international cooperation

Related monitoring

  • None

Further reading

Publications

  1. Descamps, S., Strøm, H. 2021. As the Arctic becomes boreal: ongoing shifts in a high‐Arctic seabird community. Ecology. DOI:10.1002/ecy.3485
  2. Strøm, H., Bakken, V., Skoglund, A., Descamps, S., Fjeldheim, V.B., Steen, H. 2020. Population status and trend of the threatened ivory gull Pagophila eburnea in Svalbard. Endangered Species Research 43: 435–445. DOI:10.3354/esr01081
  3. Strøm, H., Boertmann, D., Gavrilo, M.V, Gilchrist, G., Gilg, O., Mallory, M., Mosbech, A. and Yannic, G. 2019. Ivory Gull: Status, Trends and New Knowledge. Arctic Report Card 2019. https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/836/Ivory-Gull-Status-Trends-and-New-Knowledge.