If you want to see a rainbow of birds, head to the equator. A team of scientists studied more than 4,500 species of songbirds from all over the world to see how colorful they could be. They found that birds came in the largest variety of colors near the equator, the imaginary line halfway between the North and South poles that splits the globe into two hemispheres.
Since birds can see in ultraviolet light in addition to visible light, they are able to see each other in even more colors than humans can spot. Chris Cooney, the lead scientist on the project, says “being brightly colored may help individuals recognize their own species.”