SOME EVIDENCE FOR AN EFFECT OF INGESTED PETROLEUM ON THE FERTILITY OF THE MALLARD DRAKE (ANAS-PLATYRHYNCHOS)

The male and the female of monogamous pairs of mallard ducks were housed separately on each side of a removable wire-mesh partition and each bird was fed either uncontaminated food or food that had been contaminated with South Louisiana crude oil (3 ml/100 g dry weight food). Food was removed from both sides of the cage for five hr each day, and during this interval the partition was removed to permit the birds to interact physically. When both sexes consumed uncontaminated food, the imposition of this interrupted feeding regime did not alter the normal temporal pattern of ovarian development in the female and the ability of the male to fertilize eggs laid by the female was not impaired. When the male, but not the female, consumed petroleum-contaminated food ovarian development was normal but the ability of the male to fertilize the eggs was significantly reduced. However, when only the female consumed contaminated food, ovarian development was slowed significantly and the frequency of fertilization was lowered to the same extent that it was when only the male consumed contaminated food. These effects suggest that ingested petroleum contaminants may impair the development of photostimulated gonadal endocrine function in both the male and the female. © 1990 Springer-Verlag New York Inc.