Census and Population Dynamics of the White Stork Ciconia ciconia in Croatia in the years 2004/05

Abstract

Aims: This study was carried out to determine the population dynamics of the White Stork Ciconia ciconia in Croatia and to compare it with that of neighbouring countries in Europe. Study Design: The study is based on the analysis of the data of the 5th and 6th International surveys in Croatia on the pattern of 24 comparable municipalities. Place and Duration of Study: Fieldwork was carried out on the territory of Croatia in the breeding area of the White Stork in the ten years of breeding period from 1994/95 to 2004/2005. Methodology: On each White Stork location the data on nest placement and census work HPa, HP0, HPx, HPm and JZG were collected. From these data further parameters were derived: JZa, JZm, StD/100 km2 and StDBiol. Nest placements were divided into four categories. Using the software R version 3.0.1., statistical methods as Wilcoxon signed rank test and Friedman rank sum test were used in analysis. Results and Conclusion: In Croatia, overall assessment of the White Stork pairs in 2004/05 (HPaestim) is 1 714 on overall surface of 25 481 km2 with 6.73 pair/100 km2 and biological density (StDBiol) of 11.56 HPa/100 km2. Roofs and chimneys of residential and farm buildings were the most frequent nest placement (57.97%), then electric poles (38.36%) and trees (2.19%). In ten years the population trend indicates a stability of White Stork in Croatia with increase of 5.16%. Breeding success (JZa) is 2.39±0.93 and population density (StD) is 7.94 HPa/100 km2. The shift in the nest placement from the roofs/chimneys, trees and other objects to electric poles shows 15.16% nests less on roofs and 96.40% more on electric poles. The area of Nature Park Lonjsko polje is the most significant for the living and preserving the White Stork population supporting ÄŒigoč with 37 and Osekovo with 35 pairs as villages with the most breeding pairs in Croatia, mainly on roofs/chimneys.