Parentage assignment and extra-group paternity in a cooperative breeder: the Seychelles warbler (Acrocephalus sechellensis)

摘要

We describe the development and initial application of a semiautomated parentage testingudsystem in the Seychelles warbler (udAcrocephalus sechellensisud). This system used fluorescentlyudlabelled primers for 14 polymorphic microsatellite loci in two multiplex loadingudgroups to genotype efficiently over 96% of the warbler population on Cousin island. Whenudused in conjunction with the programudcervusud, this system provided sufficient power toudassign maternity and paternity within the Seychelles warbler, despite the complicationsudassociated with its cooperative breeding system and a relatively low level of genetic variation.udParentage analyses showed that subordinate ‘helper’ females as well as the dominant ‘primary’ females laid eggs in communal nests, indicating that the Seychelles warbler has an intermediate level of female reproductive skew, in between the alternative extremes of helper-at-the-nest and joint nesting systems. Forty-four per cent of helpers bred successfully,accounting for 15% of all offspring. Forty per cent of young resulted from extra-group paternity.