Generally hawks, eagles, falcons, and owls. These birds prey upon Mammals, smaller birds, and other animals. Birds that eat primarily plants, such as the Canada Goose. Birds that feed primarily on fruit. Cedar Waxwings are frugivorous birds.
Swallows are a good example.
Birds that feed largely on the nectar of flowers or the juices of fruit, such as hummingbirds. American Crows are a common example. The Osprey is piscivorous. A sac inside a bird where its neck meets the body. It holds food before digestion.