Distribution Pattern, Nest-Tree Features and Breeding Performance of Population of the Black Stork, Ciconia nigra (Ciconiiformes, Ciconiidae), in Northwestern Serbia

Abstract

Distribution pattern, nest-tree characteristics and reproductive features of Black Stork’s population were evaluated in the floodplains of Gornje Podunavlje in Northwestern Serbia over five consecutive years. In total, 44 different nests were discovered and monitored. Nests were mostly placed on wide-diameter European Oaks and White Poplars between 5.5 and 18 m above ground level. Annually, the number of occupied nests varied between 26 and 16 with the declining trend over study years. The mean nesting density was 9.8 ± 2 occupied nests per 100 km2. Through study area, occupied nests were uniformly distributed and very isolated concerning the conspecific pairs. Predominantly, Black Stork preferred to nest on the lateral branches of the autochthonous mature trees with straight trunks and extensive crowns. These results suggest that the existence of old native forest stands represent crucial microhabitat criteria in the choice of the particular nesting site. In almost half of successful nesting cases, the most frequent number of fledglings was three. Overall productivity was relatively low with some variations between years implying poor nesting success.