Birds categorize colors just like humans do. Duke Today, August 1, 2018. 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, findings suggest. Due to a phenomenon called categorical perception, zebra finches partition the range of hues from red to orange into two discrete categories, much like humans do, researchers report in the journal Nature. Picked up by Forbes, Discover Magazine, BBC News and ZME Science.