In Nederland en België gekleurringde Zwartkopmeeuwen Larus melanocephalus als zeevogel in Portugal

Several thousands Mediterranean Gulls Larus melanocephalus were observed in the winters of 2004/2005 and 2005/2006 at two sites along the west coast of Southern Portugal. Along the Lisbon coast (Guincho-Cascais-Estoril-Parede, west of Lisbon) a maximum of 6000 birds was observed and along the Alentejo coast at least 1000 birds were present in the Mira river mouth, near Vila ova de Milfontes. With an unknown, but probably considerable number of birds wintering along the Algarve coast, the total number of birds wintering in Portugal south of Cabo da Roca is estimated at a minimum of 7000-8000 birds. This estimate is six times higher than the previous estimate in the nineties of 1200 wintering birds. This increase is likely explained by the increase of the breeding population in Western and Central Europe. Behavioural observations suggest that along the Lisbon coast the birds mainly feed offshore. Sightings of colour ringed birds indicate that birds came from Belgium, the etherlands and France with a small proportion coming from other countries. The low rate of re-sightings of individual colour-ringed birds suggests that a very high number of ringed birds wintering in Portugal remained unnoticed so far. The Portuguese coast south of Cabo da Roca is clearly the most important currently known wintering site along the European and orth-African Atlantic coast, and the data gathered from colour-ring readings highlight the importance of this area as a wintering ground for the Mediterranean Gulls breeding in The etherlands and Belgium.