Гнездовая биология чёрного грифа в Тянь-Шане, Китай

Abstract

During 2016 and 2017, we observed 4 nests of the Cinereous Vulture ( Aegypius monachus ) in the middle of the Tien Shan Mountains, the west of China, and tried to follow them by the GPS/GSM dataloggers. We continuously observed nesting birds and recorded their behavior. The duration of the field works was about 40 days that makes in total more than 500 hours. The results showed that all nests of the vultures were located on the eastern slope of cliffs on the altitude of 2 300 – 2 900 meters, with the distance between nests is 1–3 km. Nests were built on the open and steep ledges with the outer diameter of the nest is 1.1–1.6 m. All clutches consists of only one egg (n=4), the incubation period was 52–56 days, and the nestlings hatched in the middle of April; the medium weight of newly hatched nestlings was 160 g. In May 17th, their weight increased to 1.50 kg, in June 14th – to 5.65kg, and in July 14th the weight of young birds was about 8.56kg (close to the adult’s weight). The brooding period in this species is very long – nestlings stayed for 90–105 days in the nest, and continued to be fed by adult birds till October. Lack of food is one of the main reasons for low reproductive success in this species.