For a small, reddish-beaked bird called the zebra finch, sexiness is color-coded. Males have beaks that range from light orange to dark red. But from a female’s point of view, a male’s colored bill may simply be hot, or not, new findings suggest.
For a small, reddish-beaked bird called the zebra finch, sexiness is color-coded. Males have beaks that range from light orange to dark red. But from a female’s point of view, a male’s colored bill may simply be hot, or not, new findings suggest.