Metal levels of feathers in birds of various food chains in southern Finland

Abstract

We examined levels of five metals (Al, Cu, Zn, Cd, Pb) in feathers of six species of birds of various food chains . In the primary consumers (Columba livia), the variability of the levels of all the metals studied was relatively high . Among the secondary (and higher-level) consumers, the variation was highest in the vole-eaters (Strix aluco, Buteo buteo), intermediate in the bird-eaters (Accipiter gentilis, A. nisus), and low in the fish-eaters (Pandion haliaetus) . Metal levels were relatively high, on the one hand, in C. livia (urban environment), and, on the other hand, in P. haliaëtus (aquatic habitat) . Cu and Pb levels were at their highest in samples near urban areas, Al and Cd in samples of aquatic food chains . The metal levels indicated that there were food web related differences in metal accumulation between species. However, a consistent tendency that levels were higher in the species of higher trophic levels than in those of the lower ones was not found.