NOTOC The Pinsk Marshes (Pinskiya baloty), also known as the Pripet Marshes (Prypiackija baloty), the Polesie Marshes, and the Rokitno Marshes, are a vast natural region of wetlands in Polesia, along the forested basin of the Pripyat River and its tributaries from Brest to the west, Mogilev in the northeast, and Kyiv to the southeast. Most of the region is in Belarus, and part is in Ukraine. It is one of the largest wetland areas in Europe. The Pinsk Marshes mostly lie within the Polesian Lowland, hence Polesie Marshes (Woodland Marshes), and occupy most of the southern part of Belarus and the north-west of Ukraine. They cover roughly surrounding the sandy lowlands of the dense network of rivers and rivulets forming on both sides of the Pripyat River, one of the main tributaries of the Dnieper. Dense woods are interspersed with numerous marshes, moors, ponds and streams extending west to east and north to south. The marshes undergo substantial changes in size during the year, with melting snows in springtime and autumn rainfall causing extensive flooding as the river overflows. The Pinsk swamps are home to 827 species of vascular plants, of which 18 are listed as endangered in the Red Book of Belarus. For the Pinsk swamps' typical alternation of open sedge-reed spaces with almost impenetrable shrub thickets. During the spring flood the swamps are almost completely covered with water, so the local population often has to cross through them in boats. On dry "islands" there are areas of deciduous or pine forests. The Pinsk swamps are home to thousands of birds from different biotopes of the Earth (Europe, Asia, Africa, Mediterranean), some of which come to nest here during migrations, and also swamps are a wintering area for many species of migratory birds nesting in parts of Northern Europe, such as Scandinavia, Finland, the Baltic states and Russia. Of the 246 species of birds which has been observed on this territory, 66 species are listed in the Red Book of Belarus.