Red feathers determine which common waxbill is the boss

For a songbird called the common waxbill, dominance isn’t governed by body size, intelligence, or even temperament, but by the intensity of the colours in their chest feathers

By Christa Lesté-Lasserre

Common waxbills with the highest social ranks aren’t necessarily larger or more intelligent than their peers – but they do have chest feathers that are a richer shade of red. This may be because individuals are so healthy that they can spare resources on accentuating their colours.

Patrícia Beltrão at the University of Porto in Portugal and her colleagues discovered this by evaluating dozens of common waxbills (Estrilda astrild) that were captured as adults in a large outdoor netted area.

The researchers measured the birds’ …