Materials on times and success of breeding of some bird species in the Sumy part of the Seym river valley. - V.N. Grishchenko. - Berkut. 5 (1). 1996. P. 56-60.
Data were collected in Sumy region in 1977-1992. They are presented in Tables. Breeding of hollow nesting birds was studied in nest-boxes. Breeding phenology of the Great Tit is considered more detail. For this species the graph of the breeding phenology was made (Fig.). The breeding success is more in the 1 reproductive cycle than in the 2 cycle and in repeated clutches. Cases of accepting of strange eggs in the own clutch by tits were ascertained. In a case those were 2 eggs of the Wryneck, in other one - 3 eggs of the Pied Flycatcher. The main causes of the death of Great Tit's clutches and broods in nest-boxes (n = 34) are the ruin by the Wryneck (35,3 %), by dormice (17,6 %). 29,4 % are the abandoned clutches. 17,6 % nests perished through other causes. [Russian].
Key words: Sumy region, Great Tit, breeding success, breeding phenology, clutch size, brood size, death.