Extra-pair paternity in a species with frequent extra-pair courtship feedings, few extra-pair copulations, and male-biased parental care

Patterns of extra pair paternity (EPP) and intraspecific brood parasitism (IBP) were studied in a Whiskered Tern Chlidonias hybrida population characterized by female brood desertion, a high level of extra pair courtship feedings (10%) and a low level of extra pair copulation (EPC; 0.6%). In this study, we used a set of microsatellite loci to analyse parentage in 56 Whiskered Tern families from southern Poland. Depending on the method, we detected that 1.4%-3.6% of chicks were sired by an extra-pair male, and extra-pair chicks were present in 3.6%-8.9% of broods. IBP was observed in 8.9%-14.3% of broods, corresponding to 3.6%-6.4% of the chicks. The low rate of EPP is in agreement with the hypothesis that in species with high male parental investment, females should avoid EPC. The low level of IBP indicates that intraspecific egg dumping is not a common female strategy in Whiskered Tern, similar to many other colonial waterbird species.

Automated summary

Patterns of extra pair paternity and intraspecific brood parasitism were studied in a Whiskered Tern population, with low rates observed due to the high male parental investment in the species. Intraspecific brood parasitism had a greater impact on chick proportions compared to extra pair paternity, the latter being relatively rare in this population.