Breeding success of black stork (ciconia nigra) in artificial nests

Breeding success of Black Stork (Ciconia nigra) in artificial Nests Forestry activities are leading to a decline in habitats suitable for Ciconia nigra throughout Europe. Fewer and fewer mature trees remain in the forests, where black storks nest. Artificial nests attached to trees can partially replace old tree branches. The main aim of this study is to investigate the factors that determine the breeding success of black storks in artificial nests. Goals of the paper: to find out what environmental factors determine the occupancy of artificial nests and the success of breeding in them; to investigate whether the nests in protected areas are occupied more often; to determine what kind of disturbances cause the abandonment of artificial nests. From 2014 to 2019, 148 artificial nests were inspected in Lithuanian forests each year. Ciconia nigra activity was observed in 31,1% of the artificial nests, while juveniles were found in 10,1% of the artificial nests. Nest occupancy began to increase rapidly in the fourth year of the study, and fell in 2019, possibly due to the drought. The most artificial nests, occupied by non-breeding black storks, were attached to pine trees, while most breeding pairs chose oaks. Most of the artificial nests with Ciconia nigra activity were found in biosphere polygons. Juvenile black storks were found in 23.3% of these nests. Ciconia nigra avoided artificial nests located less than 200 meters away from large wetlands or logging sites. In areas occupied by Haliaeetus albicilla, there were no signs of black stork activity in artificial nests. If long dry periods do not recur and there are few disturbing factors for black storks in the areas around artificial nests, these birds will likely occupy more trees with attached artificial nests and choose to breed there more often in the future