Fecundity and Progeny Growth Following Subacute Insecticide Ingestion by the Mallard

DDT thins shells of eggs from mallard ducks maintained onad libitum or controlled-feeding regimens

“…These results substantiate and extend the observations and conclusions of previous investigators (Heath et al 1969b, Tucker and Haegele 1970, Longcore et al 1971, Muller and Lockman 1972, Lehner and Egbert 1969 that both DDT and dieldrin cause thinning of shells of eggs from mallard ducks. In experiments with ducks, dietary DDT has consistently caused eggshell thinning.…”

“…Subsequently, Tucker and Haegele (1970) observed that shells of eggs from mallards fed 30 ppm of DDT were 4.9 percent thinner than those of control eggs, and Longcore et al (1971) observed that shells of eggs from black ducks Olnas rubripes) fed 30 ppm of DDE were 23.5 percent thinner at the equator than those of control eggs. Dieldrin (1,2,3,4,10,10-hexachloro-6,7-ep oxy-1,4,4a, 5,6,7,8,8a-octahydro-l,4-endo-exo-5,8-dimethanonaphthalene) fed at four ppm (Muller and Lockman 1972) and ten ppm (Lehner and Egbert 1969) of the diet has also been shown to thin shells of eggs from mallards by about four percent. Smith et al (1970) observed an 11 percent decrease in shell thickness of eggs from chickens fed ten ppm of DDT.…”

Dieldrin, Ca and P Balance, and Characteristics of the Egg in the Quail (Coturnix coturnix japonica)

“…Dramatic situations have been described concerning the levels of environmental contamination due to chlorinated hydrocarbon pesticides, highly detrimental to the populations of some species of birds of prey in the United States and western Europe, where there is a high level of DDT and dieldrin contamination (Ratcliffe, 1967;Hickey and Anderson, 1968). The deficiencies that were observed in reproduction in both birds which develop in such ecosystems and in birds which were experimentally treated with chlorinated hydrocarbons pesticides, were associated, among other manifestations, with an impaired egg-laying (Neill et al, 1969) with alterations in the characteristics of the egg shell, decrease in its weight (Adamec et al, 1972) or thickness (Bitman et al, 1970), as well as an increased embryonic mortality (Muller and Lockman, 1972). Nevertheless, the findings are highly variable and we find that Davison and Sell (1972) as well as other workers did not observe any variations in the number or weight of the eggs of hens that had been treated with DDT or dieldrin.…”