Why do some birds have bright beaks?

Brightly coloured beaks in birds are often a result of sexual selection. In many species, brighter beaks can signal health, good genes, and the ability to find food, making the bird more attractive to potential mates. For example, the male northern cardinal has a vivid red beak, which is an indicator of its fitness. Bright colours in beaks can also play a role in species identification, allowing birds to easily recognize one another. In some species, bright beaks are used in communication, signaling dominance or territory.