Warta Mouth National Park
The Warta Mouth National Park, situated in the Warta’s marginal stream valley, is dominated by open wet grasslands, pasture lands cut across by many canals and an old river bed. The Warta River flows through the middle of the Park, separating it into the northern polder and the southern protected area known as “Słońsk”. The northern section is cut off from the Warta by a flood bank, therefore the hydrological conditions are rather stable. In the southern end the annual water level fluctuations can reach up to 4 meters per year. These fluctuations are the main factor influencing the number of bird species.
The Park is one of the most valuable areas in all of Poland as far as ornithology is concerned. Unique wetlands, widespread meadows and pasture lands are the most important mainstays for water and shore birds. In the Park, 270 species of birds have been recorded. There are 160 species breeding within the Park. Each year 4 species of grebes, 8-9 species of ducks, 5 species of terns, 4-5 species of gulls and 8-9 species of waders come here to raise their nestlings. For many bird species this area is one of the most significant breeding grounds in Poland, e.g. shelduck, gadwall, oystercatcher, little gull and little tern. The numbers of some species may be significant even as far as Europe is concerned e.g. aquatic warbler, black tern, greylag goose, red-necked grebe, and shoveler. The breeding season is not the only time that the National Park is important for birds.
In the summer months a great number of waterfowl moult in the Park e.g. ducks (mallard, teal), greylag geese, mute swan, coot and recently cranes. During migrations many bird species use the area as a resting ground. It is during late autumn that the Park becomes a kingdom for arctic geese (bean and white-fronted geese) and flocks may number as many as 200 thousand individuals. The bean goose, which is the most numerous during this time, has become a symbol of Warta Mouth National Park. Throughout winter in the Park becomes a vital wintering ground for whooper and mute swans, white-tailed eagles, ducks and geese.
Among the other animal groups in the Park 39 species of mammals occur. These include: otter, ermine, badger, beaver, musk-rat, wild boar, roe-deer and American mink. It has been noted that the American mink, due to its predatory nature, has an impact on the birds in the Park. The water in the Park is very rich in fish life, among which 35 species have been confirmed. The most numerous are bream, white (silver) bream, roach, pike, perch and tench. Fish species which are under strict protection include: bitterling and spined loach.