Nature Park Kopački rit is one of the most important floodplains in Europe with large number of wetland birds. It was included in the list of Important Bird Area- IBA. In 1993 it was declared as internationally important protected area by the Ramsar Convention. In the area of Nature Park Kopački rit there are about 25 habitat types. The biodiversity of Kopački rit provides wetland birds a large food choice that they need to survive and raise chicks in the hiding places of sedges. Sedges provides them shelter from natural enemies. Climate changes, hunting and poaching negatively affects success of wetland birds nesting. Wild geese are large wetland birds that are divided into 2 genus: gray geese of the genus Anser and black geese of the genus Branta. Several species of geese belong to our European ornithofauna: Barnacle Goose, Brent Goose, Red-breasted Goose, Greater white-fronted Goose, Lesser White-fronted Goose, Greylag goose, Tundra Bean Goose, Pink-footed goose and Bar-headed Goose. The winter census occured every year in January to determine the number of wetland birds in Nature Park Kopački rit. The most numerous is the Greylag goose and the next one is Greater white-fronted Goose. The Greylag goose is the only one that nests in Kopački rit, while the others are wintering or migratory birds. The number of Tundra Bean Goose is unknown for years because they are changing wintering grounds every years. They come to Kopački rit in smaller flocks. They are mixing with Greater white-fronted geese flocks. Observation is affected by the lack of volunteers, observers during the count and unfavorable weather conditions. The count of wetland birds in Nature park Kopački rit is still incomplete.