Little Gull

Distribution, movements and phenology

This gull breeds in Scandinavia, the Baltic states, Russia and Siberia, as well as in the Great Lakes region of the USA. Outside the breeding season, it migrates to the Mediterranean, Black and Caspian Seas and to the north-east coast of America (del Hoyo et al. 1996). In Mainland Portugal, the species occurs sporadically along the entire coastline, being observed mainly during periods of migratory passage and during winter (Catry et al. 2010a). Although the movements of the species are poorly documented, most individuals from Western European populations are thought to winter and migrate at sea, occurring over the continental shelf (Hutchinson & Neath 1978; del Hoyo et al. 1996). The occurrence of the species in greater numbers along the coast is linked to adverse weather conditions, particularly strong westerly winds (Catry et al. 2010a). The birds observed in Portugal are likely to originate from Russian and Baltic Sea populations (del Hoyo et al. 1996). Some of the individuals observed migrating along the Portuguese coast may winter in the western Mediterranean, where the species’ most important wintering area in the Western Palearctic is located (Finlayson 1992). In the Azores, records of this gull are very rare (Birding Azores 2014), and its occurrence in the Madeira archipelago is also exceptional.

Abundance and population trends

It is a very scarce species in Mainland Portugal, with observations involving larger numbers referring to only a few dozen birds (Catry et al. 2010a; Ornithological Reports). In January 1996, 41 individuals were recorded during winter bird counts in Portuguese wetlands (Costa & Rufino 1996). The highest record of the species in Portugal involved 120 to 150 birds in the Douro estuary (Hoogendoorn et al. 2003) during the pre-breeding migration period. The fact that this gull has pelagic habits may explain the very low number of individuals recorded in the Iberian Peninsula during coastal censuses (Bermejo et al. 1986). In the marine censuses carried out as part of this atlas, the Little Gull was not recorded during the winter period. At sea, the species was only recorded singly or in small groups in March and April, with most of these records relating to 2009, following a period of severe storms in the North Atlantic (AEMET 2011).

Ecology and habitat

During the breeding season, this gull frequents inland wetlands, whilst during the wintering and migratory seasons it occurs along the coast. In Portugal, it can be observed along the coastline, on beaches, in estuarine areas, coastal lagoons, salt pan complexes or aquaculture sites (Catry et al. 2010a). The species is primarily insectivorous during the breeding months, with its diet varying in the winter months to include small fish and marine invertebrates (del Hoyo et al. 1996).

Threats and conservation

Globally, the population trend for this species is one of slight increase (Delany & Scott 2006; BirdLife International 2014), although no information is available in Portugal to confirm this trend. No specific threats to this gull are known, and the status of its populations is of little concern.

Autor

Meirinho et al. 2014