Evolutionary consequences of infidelity: Can extra-pair relationships give rise to sexual dimorphism?
Tuesday, April 2, 2013 - 10:01
in Biology & Nature
Male and female blue tits are hard to distinguish for the human observer. However, in the UV-range, visible to birds, the male is much more colourful. A closer look at the monogamous mating system of these birds again reveals that all is not what it seems: in every second nest there are chicks that are not related to the care-giving father. An already mated male can increase the number of his offspring by siring extra-pair offspring in other nests than the one he cares for with his mate. Researchers investigated whether this could be the driving force behind the evolution of sexual dimorphism. However, effects of extra-pair paternity are limited, cuckoldry can even reduce the intensity of sexual selection.