Color vision also enables birds to use color for other purposes. Many birds are very colorful - especially the males whose displays can attract mates, drive off rivals, and draw predators away from a nest where a drab female sits motionless. In August, mallards lose their flight feathers. The males lose their colorful breeding plumage and resemble the drab but better camouflaged females. Colors are also important for feeding the young.
Gulls have red spots on their beaks that the young peck at when they want to eat.
Young birds often have colorful red or yellow patterns inside their mouths to stimulate parents to feed them. In summary, birds rely on vision in flying, hunting and gathering food, defending territory, courtship, nesting and raising young. Their behavior is a function of what they see as well as how they are seen.