Effects of chlorpyrifos and aldicarb on flight activity and related cholinesterase inhibition in homing pigeons, Columba livia: potential for migration effects.

Homing pigeons (Columba livia) were used as a model to assess the effects of chlorpyrifos and aldicarb on flight times at sub-lethal, environmentally relevant concentrations. A significant increase in flight times of birds dosed with aldicarb and with chlorpyrifos was observed. Plasma cholinesterase activity was measured over time following exposure to either compound. The results suggest that the time of peak inhibition would correlate with migratory flight activity after exposure. In total, the results of these studies show that sub-lethal exposure to cholinesterase-inhibiting pesticides can affect the flying ability of non-target avian species.