For a reddish-beaked bird called the zebra finch, sexiness is color-coded. Males have beaks that range from light orange to dark red. But to females, a male's colored bill may simply be hot, or not, ...

“It all started when fishermen caught some strange looking sharks off the coast of Kenya,” says Dr. Rikke Beckmann Dahl of the Taiwan International Graduate Program. “They were recognizable as zebra ...