Reducing heavy metal pollution can help improve bird populations, report Finnish researchers. Tapio Eeva and Esa Lehikoinen of the University of Turku, Finland, studied pied flycatchers ( Ficedula hypoleuca ) and great tits ( Parus major ) around the copper smelter at Harjavalta, southwest Finland. A decade ago the plant started reducing emissions. The researchers noted that by 1997, the nests around Harjavalta contained on an average one chick more than they had 10 years ago. But, unlike flycatchers, tits are yet to show a recovery possibly because they feed on soil-dwelling invertebrates and it may take years before the clean up ( New Scientist , Vol 165, No 2227).