CHOLINESTERASE ACTIVITY IN WHITE-WINGED DOVES EXPOSED TO METHYL PARATHION

Captive white-winged doves (Zenaida asiatica) were exposed to various levels of methyl parathion (MP) in drinking water to determine effects on brain and blood cholinesterase (ChE) activity. We conducted two ex periments to test the influence of MP dose (the amount of MP actually ingested), MP concentration (the amount of MP per unit water), and exp osure duration (number of days exposed to a constant MP concentration) on ChE activity. Plasma ChE activity was not useful in predicting bra in ChE activity. Methyl parathion concentration had a greater influenc e on plasma and brain ChE activity levels than dose or time of exposur e. These results contribute to the evaluation of irrigation water as a route of exposure of wildlife to pesticides.