The Fieldfare nesting in the natural habitats and urban landscapes of the Western Ukraine. - A.A.Bokotey, I.M.Gorban, V.A.Kostyushin, H.V.Fessenko. - Berkut. 3 (1). 1994. - P. 22-26.
The differences between Fieldfare colonies placed in the woodlands and in the populated areas have been studied in the Volynia and Lviv regions. The comparison of the measurement and shape indices of the eggs was carried out. In the populated areas the egg length is significantly lesser during the second half of breeding period. The values of volume and maximum diameter have the same differences during the breeding period: their values are lesser in its second half. The sphericity has not alterations. Besides, in the first half of breeding period some measurement and shape indices significantly differ. These differences refer to the Fieldfare nesting in the populated areas and forming the colony in the natural habitat (the forest Velyky Lis, Volynia). The length of Fieldfare eggs is longer in the forest colony than in populated areas. The comparison of sphericity gave a contrary result. This index is larger in the Fieldfares dwelling in the populated areas. While comparing other indices, no significant differences were observed. Taking into consideration the tree species list, the essential differences were not found for the Fieldfare colonies in the populated areas and woodlands both on the distribution of nests at the tree or shrub species and on the mean values of height over the ground in the nests. The differences do not concern the nest dimensions. The earliest start of egg-laying was recorded in the new and old parks of Lviv on 1.04.1990. On this stage of breeding period the differences were being noted within in 6 days between Lviv and Zhovkva Town, 13 days - Lviv and the forest Velyky Lis, 7 days - Zhovkva and the forest Velyky Lis. According to the mean values of long standing data on the laying of the first egg, this stage of breeding period begins in the Forest Velyky Lis on the tenth day after the beginning in Zhovkva (21.04 and 11.04 accordingly). In the forest Velyky Lis the laying period of the first egg differs from that in the populated areas. In the forest colony this period lasts for 32-42 days, in Zhovkva and Lviv it is for 42-58 days. In most cases the first eggs are laid during only 5-9 days; in the populated areas this period lasts 13-16 days. In Western Ukraine two broods for one pair of the Fieldfare may occur. The second cycle of nesting is recorded in smaller number of pairs. Besides, the second egg-layings are not recorded annually. In the forest colony the quantity of years when the second breeding cycles are recorded is equal to to that of none cycles are not. In the park of Zhovkva Fieldfares nest two times yearly. In the second breeding cycle the beginning of egg-laying was 2.06.1974 in the former, and 5..06.1980 in the later. The latest beginning of egg-laying for the second breeding cycle was observed in Lviv on 26.06.1989. In the forest Velyky Lis this date was set 24 days earlier than in Lviv. If the laying duration of the first egg is defined from the extreme dates including those of the first and the second cycles of nesting for several years, its values have 48 days in the forest of Velyky Lis, 52 days in the new park of Lviv, 61 days in the old park of Zhovkva and 87 days in the old park of Lviv. [Ukrainian].
Key words: Fieldfare, Turdus pilaris, Western Ukraine, breeding ecology, nesting, egg laying.