Length 45–47 cm. Feathers black, with a purple tint. In adult birds, the base of the beak is bare; young birds have feathers at the base of the beak, but later they fall out.
Rooks are omnivores, but mainly feed on worms and insect larvae, which they find while digging into the ground with their strong beak. They love large flocks to follow the plowing land. This feature is reflected in the Latin name of the species given by Carl Linnaeus - Corvus frugilegus , “crow collecting food”.
In the northern part of the range of rooks - migratory birds, in the southern - sedentary.
They nest in trees in large colonies. The usual wintering bird of large settlements. Inhabitant of open landscapes. In the settlements near the old roads in the trees are often "rook" - colonial settlements, consisting of dozens of nests, which have been used for many years. It is omnivorous, but in winter it feeds mainly on plant food and human food waste. In winter, they stay alone and in small groups, often together with other corvids.
In the spring, the rook arrives quite early, there is still snow on the fields. The arrival period in different habitats falls between February and April. The nest is built from dry branches, it is lined with dry grass, sometimes with shreds of wool, thin branches, and also uses various debris. Gnezdovaya colony there for a very long time, even decades. Once a year, there is one clutch of 3–7 eggs. Chicks appear in early to mid-April. Incubation of rooks eggs, according to various researchers, is 16-20 days. Departures roar when they reach the age of flyouts after 30 days. They take off at the beginning of May and in the first half of June.
At the end of the 19th century, rook meat was eaten by the “poor class” in Europe and the Russian Empire, in particular, in Germany and on the Non-Black Earth Region. In Germany, the rooks salted in barrels [2] .
During trials at the University of Cambridge in England , the rooks were found to be as skilled at creating and using simple tools with their beaks as chimpanzees are at creating and using simple tools with their own hands [3] .
