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(70-21) Effects of heavy metal pollution on reproductive parameters in passerine birds. Janssens, Ellen*,1, Dauwe, Tom1, Bervoets, Lieven2, Eens, Marcel1, 1 University of Antwerp UIA, Universiteitsplein 1, Antwerp, Belgium2 University of Antwerp RUCA, Groenenborgerlaan 171, Antwerp, Belgium ABSTRACT- Because pollution has become such a widespread and expanding environmental problem, studies of the effects of pollution on birds and mammals in the natural terrestrial environment are of increasing concern. Small insectivorous passerines are considered to be good candidates for studying the effects of environmental pollution in terrestrial ecosystems. In addition to being ubiquitous, intensively studied, and high in the food chain, they are considered good biomonitors due to their high metabolic rate. In this study we examined the possible effects of heavy metal pollution on the reproduction of the great tit (Parus major). We established 4 nest box sites along a pollution gradient away from a pollution source (a non ferro industrial plant), which is the most extensively heavy metal emitting point source in Flanders, Belgium. A previous study in this area has shown that the metal concentrations in the feathers of great tits are among the highest found in passerines. This offers great perspectives to study the possible effects of metal pollution on the reproduction in these birds. We checked the nest boxes daily during the breeding seasons of 1998, 1999 and 2000 to collect breeding data. Our results showed that near the pollution source females interrupted their laying sequence more often and hatching success was markedly reduced. Great tit nestlings fledged significantly later near the factory than further away. We could not detect any differences in the weight and tarsus length of the fledglings among sites. Heavy metal (Ag, As, Cd, Cu, Hg, Pb, Zn) analysis showed that tail feathers of 15-day-old nestlings at the site next to the factory contained significant higher amounts of metals than feathers of nestlings further away. Key words: heavy metals, reproduction, passerines, biomonitoring |
