From MSNBC:
In the animal kingdom, males typically get all the color, which they flaunt in the never-ending quest for sex. Males use color, size, antlers and other showy tactics to discourage males (or in some cases, to beat them up). Now and then, the reverse is true. Usually when females are the most colorful, however, it’s because sex roles have been reversed: The females are competing for mates and the males are tending the young.
So the parrot Ecletus roratus has been an enigma. The females stay in the nest while the males forage — a typical avian family setup. Females are well outnumbered, so they don’t have to show off to get a mate. Yet while the males are plain tree-leaf green, the females stand out like Fourth of July fireworks, brightly adorned with red and blue. Mom and Dad are so different that when scientists first found them in the Australian rainforest, they though it was two different species. A new study suggests an evolutionary logic for the odd coloring.
More here.