Ardea Official journal of the Netherlands Ornithologists' Union |
Tryjanowski P. & Kuzniak S. (2002) Population size and productivity of the White Stork Ciconia ciconia in relation to Common Vole Microtus arvalis density. ARDEA 90 (2): 213-217 |
We studied population size and productivity of White Storks Ciconia ciconia in 1983-2000 in 417 km2 of the Obra river valley in western Poland and its response to Common Vole Microtus arvalis density. The 33 to 60 nesting pairs fluctuated in close accordance with vole density. Similarly, the total number of fledglings produced in the population was strongly correlated with vole density. We suggest that voles are important prey because of their high calorific value. Storks arriving from their Africa wintering quarters probably evaluate the study area with respect to available prey (mainly voles) and subsequently decide whether to breed in the Obra river valley |