Birds use hidden black and white feathers to make themselves more colourful

The green-headed tanager (_Tangara seledon_) has a hidden layer of plumage that is white underneath the orange feathers and black underneath the blue and green feathers. Daniel Field

Birds are perhaps the most colourful group of animals, bringing a splash of colour to the natural world around us every day. Indeed, exclusively black and white birds – such as magpies – are in the minority.

However, new research by a team from Princeton University in the United States has revealed a surprising trick in which birds use those boring black and white feathers to make their colours even more vivid.