Biochemical Determination of Parental Uncertainty in White-Fronted Bee-Eaters

Wrege, P.H. & Emlen, S.T. (1987). Behavioral Ecology and Sociobiology, 20:153-160.

Maternity and paternity uncertainty represent important costs to breeders among white-fronted bee-eaters (Merops bullockoides ) in Kenya. Analysis of enzyme polymorphisms reveals that between 9% and 12% of all offspring are genetically unrelated to one or both of their putative parents. These "bastards" are the result of three different sources of parental uncertainty: Extra-pair copulation, intraspecific egg parasitism, and quasi-parasitism (parasitism by a female who was fertilized by the male attending the parasitized nest). The first two represent costs to males, who rear offspring that are not genetically their own; the latter two produce the same cost for females.