LC
Sabine's Gull Xema sabini



Justification

Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
The global population is estimated to number over 340,000 mature individuals (Wetlands International 2015, Partners in Flight 2019). The European population is estimated at 1,100-2,100 pairs, which equates to 2,100-4,100 mature individuals (BirdLife International 2015).

Trend justification
The overall population trend is stable, although some populations have unknown trends (Wetlands International 2015, Partners in Flight 2019). The small European population (c.10% of global range) is estimated to be increasing (BirdLife International 2015). Increases of Sabine's Gull have also been observed in Alaska (Swaim 2017, Amundson et al. 2019).

Distribution and population

This species breeds in the Arctic and has a circumpolar distribution through northernmost North America and Eurasia. It migrates south during the autumn, wintering in the cold waters of the Humboldt current off the coast of Peru and Ecuador and off the south-west coast of Africa in the cold waters of the Benguela Current (del Hoyo et al. 1996).

Ecology

Behaviour This species is a long-distance migrant that migrates offshore between its breeding and wintering grounds (del Hoyo et al. 1996, Olsen and Larsson 2003). It returns to the breeding grounds from late-May to early-June when the Arctic tundra is still snow-covered, and breeds in colonies of 6 to 15 or occasionally up to 60 pairs (del Hoyo et al. 1996). The species may also nest solitarily or as single pairs amidst colonies of Arctic Tern Sterna paradisaea (del Hoyo et al. 1996). After breeding, the adults and juveniles depart the breeding grounds from late-July to August, migrating in flocks of up to a hundred individuals and spending the winter in small flocks or as solitary individuals (del Hoyo et al. 1996, Snow and Perrins 1998, Olsen and Larsson 2003).
Habitat Breeding The species breeds on coastal tundra wetlands in the Arctic, showing a preference for swampy, moss and sedge tundra with many lakes, floodlands and low-lying shallow brackish pools, especially where these contain islets or narrow peninsulas of grass or moss and have low, moist margins that provide feeding areas (Flint et al. 1984, del Hoyo et al. 1996, Snow and Perrins 1998). Non-breeding Outside of the breeding season the species is pelagic, occurring in cold water upwelling zones south of the Equator (del Hoyo et al. 1996, Snow and Perrins 1998).
Diet Breeding When breeding, its diet consists of adult and larval insects (e.g. springtails Collembola), arachnids, small fish and carrion, as well as small birds and the eggs of Arctic Tern Sterna paradisaea and conspecifics (Flint et al. 1984, del Hoyo et al. 1996). The species also takes seeds and plant matter on its arrival to the breeding grounds before the Arctic ice melts and other prey items become available (del Hoyo et al. 1996). Non-breeding Outside of the breeding season the species takes marine invertebrates and small fish (del Hoyo et al. 1996).
Breeding site The nest is a shallow scrape or more substantial cup of grass, moss, seaweed and feathers placed on rocky, barren or damp ground vegetated with moss or grass, usually near the edge of water (Flint et al. 1984, Richards 1990, del Hoyo et al. 1996).

Threats

No specific information on threats to this species has been recorded within Europe, however as an Arctic breeding species, it is likely to be vulnerable to the impacts of climate change including habitat change and ecosystem shifts (Ganter and Gaston 2013). Beyond Europe, the species is hunted in Russia, including egg harvesting (Merkel and Barry 2008). Neither of these threats are believed to be significant to the species as a whole.

Conservation actions

Conservation Actions Underway
The following information refers to the species's European range only: Listed under the African Eurasian Waterbird Agreement. Listed on Appendix II of the Bern Convention. It is listed within six marine Important Bird Areas across Europe. Within the EU it is listed in two Special Protection Areas in Spain. 

Conservation Actions Proposed
The following information refers to the species's European range only: Identify Important Bird Areas in the Arctic region, and subsequently designate them as protected areas, with particular emphasis on sites at sea.

Acknowledgements

Text account compilers
Hermes, C.

Contributors
Ashpole, J, Butchart, S., Calvert, R., Ekstrom, J., Elliott, N., Malpas, L. & Wheatley, H.


Recommended citation
BirdLife International (2022) Species factsheet: Xema sabini. Downloaded from http://www.birdlife.org on 09/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 09/08/2022.