Organochlorine Pesticides in the Ferruginous Pygmy Owl (Glaucidium brasilianum) in Chiapas, Mexico.

Concentrations of organochlorine pesticides were quantified in samples of feathers (n = 17) and blood (n = 15) of the ferruginous pygmy owl (Glaucidium brasilianum). The individuals were captured near the Protected Natural Area Cerro Sonsonate, Chiapas, Mexico, between February and June 2014. In both tissues, pesticides belonging to seven organochlorine chemical families were detected. However, the organochlorine pesticide concentrations differed between feathers and blood. The highest concentrations of hexachlorocyclohexanes were found in feathers (0.63 ± 0.89 μg/g), whereas the highest concentrations of ΣDrines were found in blood (0.31 ± 0.47 μg/mL). By using the summed concentrations for each of the seven families of pesticides found in feathers, we did not find any significant correlation between the pesticides and pectoral muscle or body weight (p > 0.15). The ΣDDT group was the only pesticide family that showed a positive correlation with owl body weight (r = 0.60, p = 0.05); the concentrations of these pesticides were also high in feather and blood tissues (r = 0.87, p = 0.02). Our results confirm that ferruginous pygmy owls in the study area are exposed to these pesticides.