The Phenology of Seasonal Phenomena and the Territorial Distribution of Gray Crow (Corvus cornix) from the Lower Ob Region

Abstract

The gray crow stay at the Polar circle latitude in Western Siberia lasts approximately six months, from the beginning and middle of April to the beginning and middle of October. The timing of the arrival of the gray crow to the Lower Ob region shifted to earlier calendar dates from 1970–2017. The breeding season starts in May and lasts 2.5–3 months, until late July. Postbreeding moulting starts in June and is combined with the feeding of chicks, with an ending in September. The postjuvenile moulting starts at the age of 50–55 days, in August; it lasts 2.5–3 months until the middle and end of October and is combined with migration. The departure for wintering takes place in September and the first half of October. One-year-old birds stay in the wintering area in the basins of the Kama and Volga Rivers until March–April and return to the hatching region in April–May. The space of the East European Plain is the area where crows of the northern, northeastern, and eastern populations are concentrated in winter, replacing the nomadic and migratory areas of local populations.