Comparison of trace element concentrations in grey heron and black-crowned night heron chicks.

Abstract

Cadmium (Cd), lead (Pb), manganese (Mn), zinc (Zn), and iron (Fe) concentrations were measured in the prey and liver of grey heron (Ardea cinerea) and black-crowned night heron (Nycticorax nycticorax) chicks (24-26 days after hatching) at the Pyeongtaek colony, Korea in 2001 (n = 10, respectively) and 2008 (n = 11 and n = 10). Cadmium and Pb concentrations in livers of grey heron (Cd geomean 0.06, Pb 3.90 μg/g dw) and black-crowned night heron (Cd 0.20, Pb 4.24 μg/g dw) chicks were increased with diet concentrations of grey heron (Cd 0.18, Pb 1.76 μg/g dw) and black-crowned night heron (Cd 0.20, Pb 3.96 μg/g dw) chicks. Cadmium and Pb concentrations in prey items of grey heron and black-crowned night heron chicks were a good predictor of chick liver concentrations. Cadmium concentrations in livers of both heron species collected at the Pyeongtaek heronry were relatively low and within the background level (<3 μg/g dw) for birds. Five of 20 (25.0%) grey heron and 4 of 18 (22.2%) black-crowned night heron chicks were higher than the background level for lead (>6 μg/g dw). Prey Cd and Pb concentrations were within the range of other heron and egret studies. Manganese, Zn, and Fe concentrations in grey heron and black-crowned night heron chicks were within the background or normal physiological levels reported earlier in other birds including herons and egrets.