Trans-ovo permethrin exposure in quail (Cortunix japonica)

Permethrin is a commonly used, highly effective pesticide in poultry agriculture, and has recently been trialed in conservation efforts to protect Galá​pagos finch hatchlings from an invasive ectoparasite. Although permethrin is considered safe for adults, pesticides can have health consequences when animals are exposed during early life stages. The few studies that have examined permethrin’s effects in embryonic chicks and rats have shown hydrocephaly, anencephaly, reduced cellular energy conversion, and disruption of developing heart muscle. To test whether trans-ovo exposure of permethrin affects early development in birds, we exposed Japanese quail (Coturnix japonica) eggs to cotton treated with 1% permethrin that was incorporated into nests in two amounts (0.2, 0.8 g), each with a paired untreated cotton control group. When measured on incubation day 15, we found permethrin-treated developing birds were smaller and showed signs of microcephaly, although mortality rates were the sam...