Foundling Cuckoo and Tit

The common cuckoo is one of the most perfect nesting parasites, laying its eggs in the nests of other birds. About 300 species of passerine birds act as master-educators of the chicks. The most complete list was compiled by the Russian ornithologist A. D. Numerov (see below), while all species of the Non-Vorobinoobraznye, as well as more than 10 old names that could not be identified, were excluded from it.