Rook

Corvus frugilegus (Linnaeus, 1758)

Грач | чар карга
adult
juvenile

Biology

Abundant breeding migrant and common winter visitor. Inhabits the edges of riparian, deciduous and mixed forests near the open lands; the groves, shelterbelts, trees in towns and villages; more rare lives in bushy thickets around the water in open landscapes; prefers vicinity of cultivated areas with cereal fields on plains and in foothills. Several colonies of pastinator found in Altai at 1450-1600 m. During migration and wintering occurs in towns, villages, on stubble fields, meadows and hayfields. Very gregarious species, most of the year lives in flocks numbering from several dozen to thousand birds, gathering in thousands at the roost sites. Spring migration begins in late February – early March, with arriving of most birds in first half of April; the last birds (second-years or non-breeding individuals) flies by Chokpak Pass in mid May. Breeds in colonies from 10 to 50 000 pairs which settled in March – April, sometimes together with breeding Great Cormorant, Grey Heron and Night Heron. Nest is located on tree (willow, elm, poplar, birch, pine or asp), in bush (russian olive, willow, honeysuckle, dogrose) at height 0.5-20 m above the ground or as an exclusion even on reeds; often close to other nests (e.g. up to 50 nests on one tree). Both partners repair an old nest or build new one from twigs and lined it with dry grass and some hair. Clutch of 3-6 eggs is laid in mid April – early May. Female incubates clutch while male bring the food to her and to the juveniles in first few days after hatching. Later both parents feed juveniles which fledge in end of May – mid June. Repeated breeding attempts after the first clutch loss are common. Autumn migration begins in mid – late September, most birds depart in October.

References

Gavrilov E. I., Gavrilov A. E. "The Birds of Kazakhstan". Almaty, 2005. Э.И.Гаврилов. "Фауна и распространение птиц Казахстана". Алматы, 1999. В.К.Рябицев. "Птицы Урала, Приуралья и Западной Сибири". Екатеринбург. Изд-во Уральского университета, 2000.