Some aspects of biology of the Hawfinch in forest-steppe of Sumy region. - N.P. Knysh. - Berkut. 7 (1-2). 1998. P. 70-81.
Data were collected in forest-steppe part of Sumy region (North-east Ukraine), mainly in Sumy district, in 1970-1997. Materials on migrations, wintering, breeding biology, breeding success, nesting density and feeding of the Hawfinch are given. The certain in-formation on 146 nests is received. The minimal breeding density (pairs/km2) is observed in oak forests, on edges of oak forests and in mixed forests; maximal - in alder forests, on growing felled areas and in old gardens (Table 1). The spring migration starts on the average (n = 20) March 14, comes to the end at the end of April - the beginning of May. The autumn migration is poorly expressed. It is finished on the average (n = 10) October 26. At not numerous wintering individuals the first signs of breeding excitation are shown since the end of January. In 3-rd decade of April the nest building and egg laying begins, which peak is in 1-st pentade of May (Fig. 1). The nestlings leave nests since the end of May till the beginning of July. Protraction of the breeding period is explained by often cases of a repeated nesting. The Hawfinch nests on deciduous and coniferous trees (61,6 and 2,7 % cases), their regrowth (32,2 and 1,4 % accordingly), occasionally on bushes (2,1 %). The nesting connections with 21 species of plants are marked (Table 2), thus are preferred the wild pear and apple-tree. Height of nest placing (Table 3) is caused by structure and age of a stand, on the average (n = 100) is 4,76 + 0,34 m. The arrangement (Fig. 2, 3) and sizes (Table 4) of nests are cha-racterised, their building material is analysed. The external layer (skeleton) of the nest is combined by the ramified wood rods, that promotes its durability and fastening on the substrate. Weight of nests (n = 11) in a air-dry condition is 26,63 - 80,10 g. Com-plete clutches have 3-7 eggs, on the average ( - 85) - 5,01 + 0,09. At the late nesting clutch size decreases. The egg parameters are given (Table 5). Except for typical colour egg morph 4 (4,2 %) clutches with earlier unknown cream colouring are found. Broods have 1-6 nestlings. Average brood size fluctuates from 3,25 + 0,85 up to 5,29 + 0,42 hatchlings in different years, on the average (n = 40) - 4,62 + 0,21. Hatching success changes on years from 1,30 + 0,62 up to 5,29 + 0,42 hatchlings per breeding pair, on the average (n = 55) - 3,36 + 0,32. Fledging success varies from 1,30 + 0,62 up to 4,86 + 0,55 youngs per pair, on the average - 3,20 + 0,32. The general breeding success (Table 6) total for 26 years has made 66,9 %. The greatest losses of offspring are caused by ruin of clutches and leaving of nests by birds. The reaction of Hawfinches to visiting of their nests is poorly pre-dicted. The nestlings are feeding mainly by insects (Table 7), which are marked in plenty also in feeding of adult individuals. In the summer broods of youngs pass to feeding by fruits of bird cherry, sour cherry and other plants. The certain loss to the crop of cher-ries is marked in the majority of districts of Sumy region - in 69,8 % of settlements located mainly in woody area. Almost always hawfinches prefer small-fruit non-grade cherries and especially felt cherry (Cerasus tomentosa). Primitive protective measures, used by the people, are poorly effective. The birds penetrate even to cherries covered with a transparent film and fishing nets. [Russian].
Key words: Hawfinch, Coccothraustes coccothraustes, Sumy region, biology, migration, breeding, nesting, nest, egg, breeding success, feeding, importance.
Address:
N.P. Knysh, Sumy Pedagogical Institute, Romenskaya str. 87, 244002 Sumy, Ukraine.