Hexachlorocyclohexane in Non-breeding Populations of American Kestrel (Falco sparverius) in Central Mexico.

Abstract

We studied the concentration of hexachlorocyclohexane (HCH) and isomers in blood samples of American kestrels (Falco sparverius) during the non-breeding season in agricultural fields across two states of central Mexico. The majority of the 36 kestrels we sampled were females (72%). In both, Tlaxcala and Hidalgo, the mean concentrations of ∑HCH were 0.07 µg/mL, and the presence of this contaminant did not vary between sexes, nor within or between states. We also detected the isomers β-HCH and γ-HCH (lindane) in most samples (97 and 80%, respectively), while α-HCH was the only other isomer found in a single sample. Our results confirm the presence of HCH in the non-breeding, overwintering populations of American kestrels in central Mexico. This report warrants further investigation of the timing, sources, and intake pathways of these contaminants in this migratory raptor.