all of them
a bird gets its food by hunting it, or by eating a dead carcass.
They look for it, hunt for it, swim for it, steal it, ...There are many possible options.
Wild birds either hunt, forage or scavenge for food. The hunters prey on other animals, insects or fish. Raptors like hawks and eagles do this, as well as small birds like swallows and bluebirds....
Birds are hunted as a source of food.