Contributions to the study of the avifauna from the site nature 2000 rospa0062 – “the reservoirs on the argeş river” - the wintering quarters from the middle basin of the argeş river. the hiemal season

In the present paper we present the results of our ecological research on the avifauna of some reservoirs (a site of the Nature 2000 Network) from the middle basin of the Argeş River, during the hiemal season in the period 2003 – 2010. The hibernal/hiemal season is the poorest in species of the six seasons (118 species belonging to 14 orders, 32 families and 68 genera, of which 49 species are dependent on wetlands), but the richest in the number of individuals (448,064). We also perform an analysis of the avifauna according to ecological indices (IR, constancy, dominancy, the Dzuba index of ecological significance, etc.). The Anseriformes were overdominant. It is the only season in which the order Passeriformes is complementary. Great agglomerations of Anseriformes are constantly present during the hiemal season; the specific composition and the number of individuals of the different species vary continuously on each of the reservoirs in relation to the weather conditions, the accessibility of food, etc. The highest number of Anseriformes species was observed on the Budeasa Reservoir (19 species) and the lowest on the Bascov Reservoir (12 species). The correlation between temperature and the total number of individuals of the bird species is negative. As the temperature increases, the number of individuals decreases and vice versa. The most important wintering quarter is, during our research, the Goleşti Reservoir, with impressive concentrations of waterbirds. Mention should be made of five characteristic species (eudominant and dominant) present in the area of the reservoirs in the hiemal season: Anas platyrhynchos, Aythya ferina, Fulica atra, Aythya fuligula and Larus ridibundus. The high number of subrecedent species (102) emphasizes the great fluctuation of bird species in the area as a result of the fact that these reservoirs are on the course of some European migration routes and ensure favourable conditions (halting, sheltering and feeding places) for many species of migratory birds and especially because they are, first of all, important wintering quarters. 23 species are enlisted in Annex 1(AI) of the Birds Directive.