Volume 490, 15 August 2014, Pages 114–120
Highlights
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- Pied flycatchers consume less snail shells in the heavily polluted sites
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- Diversity of snails collected by birds decreased in polluted sites
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- The closer the smelter, the higher proportion of deserted clutches and abnormal eggs
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- Brood size decreased in the polluted area, especially if snail supply was low
Abstract
During
the years 1989–91, 1997–2003, and 2005–07, we studied how emissions
from the Middle Urals copper smelter affect snail availability and
reproduction of free-living pied flycatchers (Ficedula hypoleuca).
We counted snail shells dropped in nests and analysed food samples of
nestlings. Pied flycatchers brought to nestlings fewer shells in heavily
polluted sites compared to background sites, resulting in reduced Ca
intake. Species diversity of snails collected by birds decreased with
decreasing distance from the pollution source. The pattern was the same
both in deciduous and coniferous forests. In sites closest to the
smelter, 20–50% of breeding females suffered from Ca deficiency, which
resulted in an increased proportion of deserted clutches and clutches
with defective eggshells. Number of fledglings per nest decreased in
heavily polluted sites, especially in broods with decreased snail
supply. This study demonstrated that pollution can cause both direct
effect of toxicants to birds and indirect effects via reduced Ca
availability.
Keywords
- Heavy metals;
- Acidification;
- Land snails;
- Calcium availability;
- Ficedula hypoleuca;
- Middle Urals
Copyright © 2014 Elsevier B.V. All rights reserved.
