Our return visit today to the Parque Ambiental de Vilamoura could hardly have been better timed! The ringers were just starting to pack up after what had been a fairly unproductive morning when Colin McShane appeared with a bag containing one last bird to ring - a juvenile Aquatic Warbler!
So, as on Sunday, we saw only one bird being ringed but this time it was a genuine rarity, the first of this species we have seen in the Algarve and it seems the first anyone has seen here since 2005, although several birds have been trapped and ringed further north in Portugal at Salreu.
Late August is said to be the best time to see this species in the UK as birds migrate from their breeding grounds in eastern Europe to winter quarters in West Africa. Similarly, previous records in Portugal all appear to have been in August and September so today's bird was very unexpected so late in the season.
The Aquatic Warbler Acrocephalus paludicola is the rarest and the only globally threatened passerine bird found in mainland Europe. Once widespread and numerous in fen mires and wet meadows throughout Europe, it has disappeared from most of its former range. Nowadays, its world population of only 12,100-13,800 singing males is said to be confined to fewer than 50 regular sites in only five countries (Belarus, Germany, Lithuania, Poland and Ukraine), with four sites supporting over 80 % of the global population.
On migration the Aquatic Warbler has been recorded in 13 European countries, mainly in the west and southwest of the continent. The species winters in West Africa south of the Sahara notably in the Senegal delta in and around the Djoudj National Park (Senegal).