There were always classes, even in birds. A new study reveals that female Mandarin diamondback ( Taeniopygia guttata ), a passerine native to Australia, seek out a male of the same "level", so that those that are "mediocre" or of poor quality -in metabolism, attractive or longevity – they choose a bad singing male as a partner .
The research, published in the journal Proceedings B , turns upside down the theories of evolutionary biologists, who thought that females always opted for the best males. Furthermore, experiments reveal that pairs of similar quality reproduce more quickly . "We think this is because two similar individuals are more readily accepted," says French biologist Marie-Jeanne Holveck, from the Center for Functional and Evolutionary Ecology in Montpellie. Now your challenge is to understand how females recognize which "social" category they belong to .
