The BillThe avian bill has been adapted to the niche and food requirements of the bird. Birds depend on their bills to obtain food, preen their feathers, build their nests, perform courtship displays, and defend themselves from predators or rivals. Bill shape is also a key to identifying the tropic feeding category of birds.
Bill shape determines how bird forages and eats
Identifies typical diet of the species Size & shape relates to eating habits Some adapted to courtship displays & defense against predators
Usual shapes include:
Short-swallows & nightjars - Insectivore Long-woodpeckers-Exudativores Oriole - Frugivores Conical-cardinal,grosbeak - granivores Hooked-raptors-carnivores -White eyed vireo - insectivore