Ecological peculiarities of the nesting and reproduction of Haematopus ostralegus longipes Buturlin, 1910 (Haematopodidae, Charadriiformes) in the course of the Medveditsa river (Saratov region)

The Haematopus ostralegus longipes population numbers in the conditions of the middle reaches of the Medveditsa river in the nesting period of 1996 – 2008 was stable, namely, 3 pairs, of which two, rarely three ones, nested annually. The egg laying size was 2–3 eggs. In the course of our many-year survey, a tendency has been established to significant reducing the reproduction success level against the background of transformations of the nesting and feeding stations, which is determined by the long-term tendency to reducing the water content in the river.