It is now, in the months of September and October, when we come across birds by the biological pool that are not there for most time of the year. They are small, not very shy and do what the resident birds do not know how to do, they are perching or climbing a reed shoot, from top to bottom, until they reach the surface of water to drink.
They often come in small groups. They are examples of the genus Acrocephalus, for example the Reed Warbler, whose populations in central and northern Europe live in reed beds on the banks of large lakes and rivers. On the way to Africa, where they will stay during the winter, they pass through Portugal and discover the biological pools that often offer a mini-cane grove on its banks. Thus, the birds feel almost at home and take the opportunity to quench their thirst.
Also in this sense, biological pools are important habitats to support biodiversity in Portugal and beyond.