NESTING BIOLOGY OF THE PIED FLYCATCHER (FICEDULA HYPOLEUCA, PASSERIFORMES, MUSCICAPIDAE) IN THE SOUTHEASTERN PART OF ITS DISTRIBUTION AREA

摘要

The results of long-term studies (1986-1990 and 1994-2016) on the breeding biology of the pied flycatcher (Ficedula hypoleuca Pall.) in sub-taiga forests of the southeastern part of western Siberia were analyzed. Data were collected in the surroundings of Tomsk (56 degrees 28' N, 84 degrees 54' E), with aspen-birch forests dominating. The density of nest-boxes amounted to 107 per 10 ha. In the study area, 1724 nests were examined, 1523 eggs measured, 1169 males and 1562 females caught, and 7054 nestlings ringed. The local survival rate of birds ringed as adults was 42% for males and 35% for females, the return rate (direct data) amounted to 28.4% and 26.0%, respectively, the recruitment rate for nestlings (both sexes in total) to 2.4%. The nest-boxes occupation rate (90.5%) and the population density (10.1 pairs per ha) were significantly higher than in Europe with similar densities of nest-boxes. The mean long-term median of an egg-laying date was May 25 (May 19-31.5). No certain long-term trend in the timing of reproduction was detected. The mean clutch size -6.87 +/- 0.02 eggs, the mean volume of eggs -1671 +/- 3 mm(3), the reproductive success -73.6%, the embryonic mortality -6.7%, the partial brood mortality -5.7% of the total number of hatched nestlings and 6.3% in successful nests. The mean number of fledglings for a successful attempt and a breeding attempt were 6.09 +/- 0.04 and 4.99 +/- 0.06, respectively. Thus, the study population of pied flycatcher is characterized by high indices of population density, clutch size and eggs, and the success and productivity of reproduction. This allows us to consider the reproduction conditions for the pied flycatcher in small-leaved forests of the sub-taiga belt in the southeastern part of western Siberia as optimal.