BREEDING BIOLOGY OF COMMON CHAFFINCH <i>FRINGILLA COELEBS</i> (FRINGILLIDAE, AVES) IN VINNITSA REGION
There have been numerous publications about breeding biology of birds. However, the ecology of passerine birds and specifically chaffinches of the urban landscapes of the Eastern Podillia region is little known and mostly outdated. Therefore, the current research in phenology, nesting and oology of chaffinches is rather important. The data was recorded during 2010-2013 in Vinnytsia city by a traveling method. The birds population density and biomass were calculated. In total 48 chaffinches nests were examined and 222 eggs measured. The measurements included the spheroid index (Sph), eggs volume (V), length (L) and the maximal diameter (B). For chaffinches both nest and migrate through the Vinnytsia region the nesting season starts in the late March (n=4, M=20,03, lim: 03,03-11,04). It depends on the birds arrival date and the weather. The earliest eggs laying was noted on May 06, 2012 and May 08, 2013. The majority of new eggs laying (n=38; 80 %) appears in May. The reproductive activity of birds significantly decreases in June. During the nesting period the population density varies from 3 to 7,8 bird/km <sup>2</sup> and the biomass equals to 0,071-0,168 g/km <sup>2</sup>. These species populate parks, orchards and urban gardens. The chaffinches also nest on tall trees of the city high-rise buildings. The nests were located on spruces (n=24; 50 %), birches (n=10; 20,8 %), alders (n=6; 12,5 %), lindens (n=5; 10,4 %) and pines (n=3; 6,3 %). Most of the time the nests were situated at the 1,5-3 meter level (n=29; 60,4 %). Occasionally they were placed below 1,5 meters - 4,2 % (n=2) and above 3 meters - 35,4 % (n=17). The nests had a traditional bowl-shape. Most of the time - 85,4 % (n=41) - the nests were located at the bases of side branches, by the trunk. The rest - 14,6 % (n=7) - were situated in the bifurcations of side branches, approximately 18-96 cm from the trunk. Besides the usual nesting building materials, the chaffinches used a wadding, pieces of paper and plastic bags. In Vinnytsia the chaffinches usually lay five (n=32; 66,7 %) or four (n=14; 29,2 %) eggs. Only one nest had six eggs (n=1; 2,1 %). During the incubation and feeding the chicks, 10 out of 48 studied nests were destroyed (20,8 %). In nine cases, the chaffinches were eaten by Corvus cornix (33,3), Garrulus glandarius (55,6) and Dendrocopos major (11,1 %). The young chaffinches fly the nest in June-July at the age of 13-14 days. In 10-12 more days, they become independent and start to migrate. The last wave of the autumn migration was observed in the late November (n=4, M=07,11, lim: 18,10-27,11). During the period of 2002-2013, we had observed five chaffinches wintering in different areas of Vinnytsia region. We concluded that if enough plant food is available and an additional feeding is provided, the birds are capable of wintering every year in the Eastern Podillia region. Further study of chaffinch biology in urban areas will help in finding and timely eliminating of possible threats for the chaffinch population.