Variation in diet composition: a hazard to the reliability of the LD50-test.
The severity of toxic effects on nearly fully-grown birds from an organophosphorus insecticide (isofenphos) was shown to be affected by the tested birds' previous diet as juveniles. Subadult grey partridges (Perdix perdix), with an insect-poor diet as juveniles, were severely affected by the insecticide, whereas birds fed an insect-rich diet as juveniles showed no signs of poisoning after feeding on isofenphos-treated seeds.
Dahlgren
J
J
Department of Animal Ecology, University of Lund, S-223 62 Lund, Sweden.