The use of feathers to monitor heavy metal contamination in herons, Korea

Abstract

This study measured concentrations of iron, manganese, zinc, copper, lead, and cadmium in environmental substrates (water and sediment) as well as in the diet and feathers of Black-crowned Night Heron Nycticorax nycticorax and Grey Heron Ardea cinerea chicks from Pyeongtaek heronry, Gyeonggi-do, Korea. Zinc and cadmium concentrations in sediment were relatively high, but lead was low. In the diet, only copper concentrations were higher in Black-crowned Night Herons than in Grey Herons. Cadmium concentrations in the diet of two heron species from a Pyeongtaek heron colony were also higher than reported in other studies. In feathers, iron, copper, and lead concentrations were significantly different between heron species. Iron and copper concentrations were higher in Black-crowned Night Heron chicks than in Grey Heron chicks, but lead concentrations were not. Therefore, with the exception of lead, heavy metal concentrations in feathers were not related to concentrations in the diet. Zinc, iron, and lead concentrations in heron feathers were within the ranges reported by other heron studies, but manganese, copper, and cadmium were much higher. Lead and cadmium concentrations in feathers of Black-crowned Night Heron and Grey Heron chicks were elevated to lead and cadmium concentrations in the diet. Therefore, we suggest that lead and cadmium concentrations in heron feathers reflect contamination of breeding sites and are useful bioindicators of local contamination.