FROM POPULATIONAL OBSERVATIONS TO AN ASSESSMENT OF THEIR STATE: EXPERIENCE FROM A COMPREHENSIVE STUDY ON THE DEMOGRAPHIC PARAMETERS OF THE WESTERN SIBERIAN POPULATION OF THE EUROPEAN PIED FLYCATCHER, <i>FICEDULA HYPOLEUCA</i> (MUSCICAPIDAE, PASSERIFORMES)

Abstract

Key demographic parameters were calculated using the European pied flycatcher (Ficedula hypoleuca) as a model species for the study of bird population ecology. In the Tomsk Region, southeastern part of western Siberia, birds nesting in nest boxes situated in natural forests for 22 years were continuously studied. Where possible, life tables, probability models (CJS), and population matrix models were employed in the calculation of demographics. A comprehensive study of population characteristics made it possible to compare them with the results of other research and to demonstrate the degree of divergence in the estimation of demographic parameters obtained using different methods. On average, nestlings successfully left their nests in 87.6% of breeding attempts. The percentage of immigrants, residents, and autochthons in the static age distribution of females amounted to 41.7, 25.3, and 33.0%, respectively, vs 30.8, 25.3, and 43.9% in males, The maximum age for female autochthons was 7 years, compared to 8 years for male autochthons. Male residents lived to be x + 5 years old, while female residents lived to be x + 7 years old. Autochthonous males and females showed about the same local survival rates. These were the highest in yearlings (0.54) and gradually decreased with the age of individuals. The local survival rate of males of unknown origins is comparable to that of autochthonous males. Females of unknown origins had the lowest local survival rates. Birds could start nesting as young as one year old and as old as six years. Ringing revealed that 68.9% of males started breeding in their first year of life, compared to 59.9% of females that started in their first year. Only 39.2% of females and 46.3% of males among the birds that survived and returned to our control sites started breeding as yearlings, vs 66.9% of two-year-old females and 71.1% of males. The proportion of the birds that returned to their birth place amounted to 11.1%. Females produced 9.1 fledglings on average per lifetime, vs 9.6 fledglings for males. The minimum life expectancy for fledglings was 1.2–1.49 and 1.2–1.62 years, vs the maximum life expectancy for individuals that survived for one year, which was 1.94 and 1.96 years for males and females, respectively. For males and females, the generation time was 3.13–3.32 and 3.18–3.39 years, respectively. The sensitivity and elasticity analysis of the population growth rate based on the constructed projection matrix revealed that it was the survival rate of juvenile and sexually mature individuals between one and two years of age that primarily drove the population growth rate. Using the demographic data obtained for the species’ population in natural habitats in the Southeast of western Siberia and the population matrix model constructed on its basis, we believe it is possible to compare the state of populations inhabiting ecosystems, both unspoiled and disturbed (transformed), in various areas across the distribution range of the European pied flycatcher.