Abstract:

During the years 1994-2009, the number of White Stork pairs breeding in the city of Wrocław (293 km²) fluctuated between 5 pairs in 1999 and 19 pairs 2004. Most nests were clumped in two sites in the Odra river valley. Two nests were located only cca. 1 km from the city hall. The fluctuations in numbers can be linked to the availability of feeding grounds and weather. In years when grass was mowed in the Odra valley, the number of White Storks was higher than in years when the grass was left unattended. Overall, the mean number of fledglings per successful pair during the years 1995-2009 was slightly higher in the rural than in the urban area. Contrary to expectation,  the mean number of fledglings per successful pair was the highest in the year of highest population density. In two rural counties adjacent to Wrocław, the number of breeding pairs was similar to that in the city in 1994/95 (15 vs. 13 pairs). However, in 2004 the number of breeding pairs in the city almost doubled compared to that in the neighboring counties (10 vs. 19 pairs). After a sharp decline between 2004 and 2008, populations in both areas were similar in 2009 (5 vs. 4 pairs), but much lower than in 1994-1995. Wrocław is probably the only large city (>100,000 people) in Poland, where the White Stork has developed a sizeable, although fluctuating, breeding population. One of the most powerful role the city-nesting White Storks may play is their ability to engage directly citizens with nature and facilitate in that way environmental education and awareness.