DDE thins eggshells of captive American kestrels

EGGSHELL thinning in several species of raptorial and fish-eating birds, whose populations and/or reproductive success have declined dramatically in recent years, has been correlated with residues of DDE [1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene] in their eggs^1–3. DDE, a common metabolite of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane] and a nearly universal contaminant in the food of these birds, has been considered to be the major chemical responsible for eggshell thinning.