Low Extra-Pair Paternity and Polygamy in the Common Kingfisher Alcedo atthis

Abstract

SummaryMonogamy was considered to be the most common mating system in birds. However, molecular techniques revealed numerous cases of extra-pair fertilisations (EPFs) in most bird species as well as multiple partners during breeding season. In this study, we examined the population of the Common Kingfisher Alcedo atthis breeding along the Danube River system in Slovakia during three consecutive breeding seasons (2016-2018). We analysed 618 individuals – 70 adults and 548 nestlings from 87 broods. Overall, six nestlings (1.09%) from three different broods (3.45%) were fathered by other than the pair male. None of the nestlings had a mother other than the pair female. Besides that, we detected two simultaneously polygamous males (5.13%). In seven cases (9.72%) we revealed mate change between different broods: female change in three cases (4.17%) and male change in four cases (5.55%). The occurrence of extra-pair nestlings as well as polygamy was not associated with the synchronicity of breeding attempts at the beginning of the season, while the type of mating strategy seems to be associated with nest density. At the same time, male body condition was unrelated to the type of mating strategy in which he was engaged. Conversely, polygamous males had higher genetic diversity (observed heterozygosity) than monogamous ones. No difference in genetic diversity was found between monogamous and polygamous females. There was no difference in breeding success before and after the change of partner. In addition, polygamous individuals did not have more young than monogamous birds, suggesting that having more than one partner does not ensure greater breeding productivity. This is probably why polygamy remains a minority strategy in the Common Kingfisher.—Cepková, M., Melišková, M. & Rubáčová, L. (2023). Low extra-pair paternity and polygamy in the Common Kingfisher Alcedo atthis. Ardeola, 70: 41-58.