AVIS-IBIS

Birds of Indian Subcontinent

Male-Biased Sex of Extra Pair Young in the Socially Monogamous Red-Backed Shrike Lanius collurio

Publication Type:Journal Article
Year of Publication:2008
Authors:Schwarzová, L, Šimek, J, Coppack, T, Tryjanowski, P
Journal:Acta Ornithologica
Volume:43
Issue:2
Date Published:2008
ISBN Number:0001-6454
Keywords:Collurio, Czech Republic, Laniidae, Lanius, Lanius collurio, Lanius schach
Abstract:Abstract. Females of many socially monogamous bird species engage in ? or even actively seek ? copulations outside their social pair bond. However, in socially monogamous birds with low breeding abundance, such as the Red-backed Shrike, extra-pair paternity (EPP) was thought to be an exceptional and random incident. Drawing on samples collected in an unusually dense Red-backed Shrike population in the Czech Republic, we show through DNA microsatellite typing that among 65 chicks from 15 nests, 10 individuals (26.5%) had been sired by males other than the nest-attending social mate. All 10 extra pair young were of male sex. In all cases, genetic fathers of extra pair young stemmed from neighbouring territories. Extra pair fathers had significantly longer tarsi than social mates, indicating that female choice was a function of age-class dependent male body size. Our findings support sex allocation theory, which suggests that promiscuous females mating with higher quality males should produce mostly sons.Abstract. Females of many socially monogamous bird species engage in ? or even actively seek ? copulations outside their social pair bond. However, in socially monogamous birds with low breeding abundance, such as the Red-backed Shrike, extra-pair paternity (EPP) was thought to be an exceptional and random incident. Drawing on samples collected in an unusually dense Red-backed Shrike population in the Czech Republic, we show through DNA microsatellite typing that among 65 chicks from 15 nests, 10 individuals (26.5%) had been sired by males other than the nest-attending social mate. All 10 extra pair young were of male sex. In all cases, genetic fathers of extra pair young stemmed from neighbouring territories. Extra pair fathers had significantly longer tarsi than social mates, indicating that female choice was a function of age-class dependent male body size. Our findings support sex allocation theory, which suggests that promiscuous females mating with higher quality males should produce mostly sons.
URL:http://dx.doi.org/10.3161/000164508X395379
Short Title:Acta Ornithologica
Taxonomic name: 
Laniidae (Birds), Lanius (Birds), Lanius collurio (Birds), Lanius Collurio (Birds), Lanius schach (Birds), Lanius Schach (Birds)
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith