DDE in birds: Lethal residues and loss rates

Lethal brain residues of DDE were determined experimentally in four species of wild birds (male common grackels (Quiscalus quiscula ), immature female red-winged blackbirds (Agelaius phoeniceus ), adult male brown-headed cowbirds (Molathrus ater ), and immature female starlings (Sturnus vulgaris ) given dietary dosage of 1,500 ppm DDE until one-half had died, then sacrificing the survivors, chemically analyzing the tissues, and comparing results in dead birds and survivors. In all species, residues of 300 to 400 ppm of DDE in the brain were considered to show increasing likelihood of death from DDE, confirming results of an earlier study with a single species. Body residues (ppm wet weight) were not diagnostic, overlapping grossly in dead birds and survivors, but averaging higher in survivors.