Charakterystyka wybranych parametrów populacyjnych bociana białego (Ciconia ciconia) w środkowej Polsce

Abstract

On the basis of the so far collected and/or published data on the White Stork of central Poland (the Łódź Upland) the authors undertook an attempt to explain the spatial and tem poral distribution of breeding efficiency, population density as well as nests localization and nest distribution in relation to human settlements. The efficiency of White Stork breeding depends on biotopic conditions and interspecific competition. Precipitation in spring has a positive while precipitation and low temperatures in June a negative impact on interspecific competition. Habitat conditions of the White Stork have begun to display a constant tendency to decrease in quality, mainly due to land draining. The interspecific competition depends on biotopic conditions and on density. Optimal habitat conditions, including weather ones, may largely neutralize the impact of the intraspecific competition, which enables the population an increase in density, leading even to the appearance of aggregations and colonies. A deterioration in habitat conditions increases interspecific competition, which decreases breeding success to a lower extent than that which could be expected, caused decomposition of aggregations and decrease in the density of breeding pairs. The appearance of a nest outside of the settlement area is a result of interspecific competition.