Feathers evolved in dinosaurs and are a key characteristic of birds today. They are arranged in a precise hexagonal pattern in a bird's skin, but it has been unclear how this happens. According to a ...

On the open savannas of East Africa, a flock of vulturine guinea fowl looks almost unreal. Bodies are patterned with crisp black and white lines. Chests and backs glow a deep, cobalt blue. Against the ...