Environmental Factors Affecting Nest-Site Selection and Breeding Success of the White Stork (Ciconia ciconia) in Western Turkey

Abstract

We investigated nest site selection and breeding success of White Storks (Ciconia ciconia) in relation to geographical features, weather, and land use in western Turkey. Locations of nests in relation to altitude, distance to the nearest river and stream, slope, and aspect were examined between 2008 and 2010 in Sındırgı District. Population dynamics of breeding White Storks were surveyed in the central town in 1984, 1987, and between 1992 and 2010. White Storks nested in only 17 of 74 settlements. Twenty-six of 46 nests were occupied in 2010 with a mean density of 1.72 breeding pairs/km2. Settlements with nests were significantly lower (x ± SD) in elevation (283.3 ± 77.3 vs. 622.5 ± 230.7 m) and closer to the nearest river (1,646.2 ± 1,004.5 vs. 4,101.7 ± 3,231.5 m) than settlements without nests. No significant difference was found between the mean aspects of the settlements and the distances to the nearest stream between these two groups of settlements. The number of breeding pairs and fledglings had a significantly decreasing trend throughout the study period. The number of breeding pairs was positively correlated with the annual total area of crop fields and negatively correlated with the total area of fruit production. The number of breeding pairs was positively correlated with total and maximum precipitation in April, but breeding success was negatively correlated with mean total precipitation and mean maximum precipitation during the breeding season.