Intentional Poisoning Of Birds With Parathion

Intentional poisoning of birds by farmers is not uncommon but is rarely documented and given proper attention. Two recent cases from New York are illustrative. In the first, at least 5,120 birds, mostly Red-winged Black- birds (Age&us phoeniceus), Common Grackles (Quisculus quisculu) and Brown- headed Cowbirds (Molothrus ater) were killed by parathion- (an organophosphate insecticide) treated corn, which had been distributed on a truck farm in mid- March. In the second, at least 3,196 birds, mostly Common Grackles, Red-winged Blackbirds and European Starlings (Sturnus vulgaris), died after ingesting para- thion-treated rye seed spread near unharvested field corn in late March. A Cooper's Hawk (Accipiter cooperil), two Red-tailed Hawks (Buteo jamaicensis) and an American Kestrel (F&co sparverius) were killed in these cases after consuming noisoned icterids. Small numbers of birds in six other species were also killed in these incidents. Parathion (Phosphorothioc acid O,O-diethyl 0-(4nitrophenyl) ester), an organophosphate insecticide that has been widely used for many years, is highly toxic to birds. The median le- thal oral dose (LD,,) of parathion varies from 0.125-0.250 mg/kg for Fulvous Whistling- Ducks (Dendrocygna bicolor) to 24.0 mg/kg for Chukar (Alectoris chukur; Tucker and Crabtree 1970, Schafer 1972). Accidental deaths of nu- merous wild birds have resulted from the ag- ricultural use of parathion. White et al. (1982a, b) reported the deaths of over 1,600 waterfowl, mostly Canada Geese (Branta canadensis), from applications of parathion to agricultural fields in Texas. More insidious and less ap- preciated is the use of parathion to deliberately poison wild birds. Carson (1962) described the purposeful killing, by farmers, of an estimated 65,000 birds with parathion. Farmers continue to intentionally kill birds with parathion and this report describes the investigation of two recent cases in New York State. METHODS