GENETIC-EVIDENCE FOR EXTRA-PAIR FERTILIZATIONS IN SOCIALLY MONOGAMOUS SHORT-TAILED SHEARWATERS, PUFFINUS-TENUIROSTRIS (PROCELLARIIFORMES, PROCELLARIIDAE), USING DNA FINGERPRINTING

Genetic relationships between adults and nestlings of the short-failed shearwater, Puffinus tenuirostris, were analysed by multilocus DNA fingerprinting. Short-tailed shearwaters are socially monogamous, forming strong pair bonds, often for many years. The human polycore minisatellite probe, 33-6, revealed sufficient variation in shearwater DNA to allow individual-specific identification. A total of 22 nestlings and 32 adults, comprising 10 trios of nestling and both parents, and 12 pairs of nestling and only one parent, were examined. Analysis of fingerprint profiles revealed four cases where a nestling was not related to one of the attendant adults, and may have resulted from an extra-pair fertilisation. Extra-pair fertilisations, as an alternative breeding strategy, are discussed with respect to the biased and low reproductive output of this long-lived species.