||Effects of Dietary Exposure to Methyl Parathion on Egg Laying and Incubation in Mallards.
Bennett, R. S. ;
Williams, B. A. ;
Schmedding, D. W. ;
Bennett, J. K. ;
||Corvallis Environmental Research Lab., OR. ;NSI Technology Services Corp., Corvallis, OR.
Methyl parathion ;
Organophosphate insecticides ;
Food consumption ;
Anas platyrhynchos ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
||An outdoor pen study was conducted with mallards (Anas platyrhynchos) to evaluate the effects of an 9-d dietary exposure to methyl parathion (400 ppm) on egg laying and incubation when treatment was initiated at different times in the nesting cycle. Treatment groups were defined as egg laying (chemical initiated after fourth egg laid in nest), early incubation (initiated after day 4 of incubation), late incubation (initiated after day 16 of incubation) and control (no chemical). Forty-eight pairs (12/group) were allowed to nest and hatch broods. In the egg laying group, daily egg production was reduced significantly during the treatment period compared to controls, but 4 of 10 hens resumed production post-treatment. One of ten control hens abandoned its nest, whereas 17 of 23 hens in the early and late incubation groups either died or exhibited changes in incubation behavior, with 7 hens abandoning their nests and 6 displaying reduced nest attentiveness for one or more days during treatment. Reproductive parameters were not significantly different between treatment groups, but the number of hatchlings per nest was 61, 43 and 58% of controls for the egg laying, early incubation and late incubation groups, respectively. The study showed that nesting success may be impacted by short dietary exposures to methyl parathion, particularly during early incubation.
||Pub. in Environmental Toxicology and Chemistry, v10 p501-507 1991. Prepared in cooperation with NSI Technology Services Corp., Corvallis, OR.
|NTIS Title Notes
||Reprint: Effects of Dietary Exposure to Methyl Parathion on Egg Laying and Incubation in Mallards.
||PC A02/MF A01