Atlas of Seabirds of Portugal

Distribution, movements and phenology

The Yellow-legged Gull breeds between April and August in Europe, the Middle East and North Africa, and is resident mainly in the coastal areas of the Iberian Peninsula and France, the Mediterranean, the Black Sea and the Caspian Sea, as well as in the Azores, Madeira and the Canary Islands. In winter, it is distributed along the European Atlantic and Mediterranean coasts, from Denmark to Western Sahara (Billerman et al. 2026). In Portugal, it nests mainly along the entire Mainland coast and on most of the islands and islets of the Azores and Madeira (Oliveira et al. 2023b). Although sedentary, some individuals undertake wider dispersal movements along the entire Portuguese Mainland coast (Fernandes et al. 2025), in Spain and Morocco, and occasionally to more distant countries in northern Europe and the Mediterranean. At sea, it has a distinctly coastal distribution, rarely venturing beyond the continental shelf (Meirinho et al. 2014; Romero et al. 2019).

Based on the individual tracking of 201 birds from colonies on Mainland Portugal and in Spain, the known distribution for the Mainland region is confirmed. This type of information was not made available for the colonies in the Azores or Madeira.

Abundance and population trends

The European population has been estimated at between 409,000 and 534,000 pairs, with a growing population trend (BirdLife International 2025).

Currently, the Portuguese population numbers between 7,350 and 8,000 pairs, with the largest colonies on the Mainland (Oliveira et al. 2023b). The latter reached a peak in the 1990s, with 45,000 individuals on the island of Berlenga alone (Catry et al. 2010a). Since then, control measures in this colony have contributed to a reduction in the population, reaching 2,200 pairs in 2022 (Ceia et al. 2023). Despite the decline in the Mainland population abundance, there has been an expansion in its distribution, mainly due to the occupation of urban areas. In other regions, a reduction in population numbers has also been recorded in recent decades, with currently 1,606 to 1,712 pairs in the Azores and 52 to 105 pairs in Madeira (Oliveira et al. 2023b).
The Mainland and Azores populations have achieved Good Environmental Status for the abundance indicator, unlike the Madeira population, reflecting the sharp decline in its abundance.

Ecology and habitat

This gull utilises a variety of coastal habitats, such as beaches, fishing harbours, agricultural fields, urban areas, salt pans and landfills (Matos et al. 2018; Mendes et al. 2018). The distribution of this species appears to be linked to the high availability of food, obtained at landfills, near boats and in fishing harbours (Pereira et al. 2025b). Its generalist diet includes fish, pelagic crabs, insects and waste generated by human activities (Lopes et al. 2021). It is also a known predator of other seabirds. It nests preferentially on islands, islets, coastal cliffs and in urban areas.

Threats and conservation

In Portugal, some individuals are frequently captured as bycatch in fishing gear such as gillnets and longlines (Calado et al. 2021; Pereira et al. 2025a). Furthermore, the species faces other threats such as marine pollution (Lopes et al. 2021; dos Santos et al. 2024; Veríssimo et al. 2025) and diseases (Casero et al. 2025). Excessive population numbers in some colonies can place significant pressure on other natural elements, notably flora, other birds and reptiles. Some of these may have increased conservation value, as they are endemic with a limited distribution and/or have an unfavourable conservation status. It is urgent to ensure proper management of urban and fisheries waste in order to limit the unregulated growth of the Yellow-legged Gull.