Multilocus fingerprinting and single locus analyses in the great tit for paternity determination.

In order to arrive at detailed information about the occurrence of alternative reproductive tactics in the great tit (Parus major) we examined parental lineages by multilocus fingerprinting in 51 great tit broods containing 429 nestlings. In 45% of the broods at least one nestling was found to stem from copulations with males other than the social mate of the female. Single broods contained up to 62% extra-pair young (EPY). Single locus profiling revealed how many fathers were involved in extra-pair paternity (EPP) within each brood: In most cases a single male is the genetic father of all EPY in a given brood.