All faunivores rely on very competent digestion by their own enzymes. There are no special digestive sites for microbial fermentation.A defining adaptation of most faunivores is the capacity to separate the highly digestible soft tissues from relatively indigestible components, such as arthropod skeletons, bones, fur, feathers, fins, scales, and shells. Sometimes the bird uses its beak to separate these items, but it also occurs in the gizzard followed by egestion of the indigestible components back out of the mouth.
Animal tissues digest easily and are high in protein with a balance of essential amino acids that is similar to the bird's requirement.