PIED FLYCATCHER FICEDULA HYPOLEUCA (PALLAS, 1764) IN THE VORONEZH STATE NATURE RESERVE: THE BREEDING ECOLOGY IN THE SOUTHERN PART OF THE EUROPEAN RANGE IN A CHANGING CLIMATE

The breeding ecology of pied flycatchers Ficedula hypoleuca (Pallas, 1764) was examined on the birds nesting in artificial nests. The material was gathered from 1986 to 1996 and from 2012 to 2021 in the Voronezh State Nature Biosphere Reserve (50°21ʹ–52°02ʹ N, 39°21ʹ–39°47ʹ E). Five hundred twelve nests were observed. The spring bird arrival varies over the years from the 12th of April to the 5th of May. The average date is the 23th of April (n = 34), the time frame of the bird arrival correlates with the temperature in April (r = −0.42, p < 0.05). Oviposition begins in a narrow time range from the 5th to the 9th of May. The beginning and the synchronism of oviposition negatively correlate with the air temperature in the first ten days of May (r = −0.72, −0.81, p < 0.01). The long-term dynamics of bird arrival and oviposition time frames lack any linear trends. The clutch size varies from 3 to 9 eggs, 6.63 ± 0.05 on average (n = 466). The proportion of successful breeding attempts is 15–96.3%, the general breeding success is 9.8–93.2%; the average number of fledglings per one breeding attempt is 4,41. The major factor of egg and nestling mortality is predation of a forest dormouse Dryomys nitedula Pallas, 1778 in deciduous forests. In the current century the level of predation lowered substantially. The embryonic mortality proportion is 0.8–14.5% and negatively correlates with the air temperature during the oviposition period (r = −0.7, p < 0.05). The population in the south of the range is marked by a high density of the artificial nests colonization in pine forests, stable breeding time frames and high breeding productivity. The inter-annual fluctuations of climatic variables have no crucial bearing on the breeding time frames and productivity. The climate grows warmer mainly due to the temperature rise in winter and in the first half of spring, that means little for the researched species as it is a late migrant breeding in May and June.

pied flycatchers, bird breeding ecology, climate change