Blue Tit (Cyanistes caeruleus) Science Article 19
abstract
In socially monogamous species, extra-pair paternity can increase the variance in reproductive successand thereby the potential for sexual selection on male ornaments. We studied whether male secondarysexual ornaments are selected through within- and/or extra-pair reproductive success in the blue tit (Paruscaeruleus).
Kaspar Delhey et al, Proc. R. Soc. Lond. B 7 October 2003 vol. 270 no. 1528 2057-2063