Population Trend, Phenology and Dispersion of Common Waterfowl Species in Hungary Based on a Ten Year Long Time Series of the Hungarian Waterfowl Monitoring

Abstract

The HUNGARIAN WATERFOWL MONITORING (HWM) takes place at 48 observation units. The current study shows the 25 common waterfowl species, their trend, phenology, and dispersion in Hungary using the data of a ten-year period between the 1996/1997 and 2005/2006 seasons. The six commonest species were: Anas platyrhynchos, Anser albifrons, Anser fabalis, Anser anser, Anas crecca and Fulica atra. During the ten-year period there were 8 species with about 1000 individuals or less (Anser erythropus, Mergus albellus, Tachybaptus ruficollis, Phalacrocorax pygmeus, Netta rufina, Podiceps nigricollis, Cygnus olor, Mergus merganser). We report a heavy increase of Aythya nyroca, Phalacrocorax pygmeus, Netta rufina, Podiceps nigricollis, Anas clypeata, Cygnus olor, Anser albifrons, Podiceps cristatus, Anser anser, Anas strepera and a slight increase of Phalacrocorax pygmeus and Tachybaptus ruficollis. A strong decrease can be seen in Anser erythropus, Aythya fuligula, Anser fabalis, Anas querquedula, Aythya ferina, Anas crecca, Mergus albellus, Anas penelope, Mergus merganser, a slight decrease in the case of Anas platyrhynchos and Bucephala clangula. The 25 species were put into six different groups based on their types of phenology: late summer migrating species, species migrating dominantly in autumn, over wintering species, species passing through Hungary dominantly in spring, spring and late summer migrants, species with a stable population. Eco-geographical differences between Transdanubia and the Great Hungarian Plain explain the differences in the dispersion of species: distribution dominance in Transdanubia, dispersion dominance in the Great Hungarian Plain, even distribution. Our conclusions confirmed some of the earlier results, but in some cases we made conclusions different from the earlier suggestions. It is obvious that changing environmental conditions affect the changes in population parameters of waterfowl species.