"What's really exciting about this work is that we're looking more closely at those pairs that do have extra-pair fertilizations and try to figure out what's going on with them.
Sandercock said what appears to be going on is that the infidelity is a direct result of avoiding inbreeding. Genetic studies indicate that the rate of genetic similarity among the mated pairs of birds with extra-pair fertilizations is more closely related than pairs without extra-pair fertilizations. How the species are able to recognize a genetically similar partner is still a mystery, he said,
"We don't have a good sense of how females are doing this; how they assess how similar they are genetically to a mate," Sandercock said. "It implies that there is some sort of recognition mechanism that we don't fully understand.
Another mystery scientists have yet to uncover is what are the consequences of inbreeding?
"We don't have a good measure of what would have been the fertility of the eggs or the growth and survival of the chicks after hatching if she had not selected a mate other than her partner," Sandercock said. "But in a number of other birds those sorts of costs of inbreeding are fairly well-documented."
Contact: Brett Sandercock
Kansas State University