What are owl pelets?

An owl pellet is a conglomeration of undigested material that the owl has regurgitated. This is not fecal material. It is regurgitated out of the beak. It is a consequence of a canivorous bird eating its prey whole. Hawks and falcons do the same thing.

These pellets look gray or brown and are an inch or two long (3-5 cm). They often contain a lot of hair and so a person may easily think it is the decayed remains of a dead mouse. It can include a mouse meal, but it is what remains after after the bird has finished digestion. There is clearly an evolutionary advantage to a process that extracts the high value nutrients which may represent a small fraction of the material in the meal. It saves the energy of processing indigestible material and saves the weight, perhaps the most important aspect for a bird.

A bird's pellet can be analysed to determine its diet and may the pellet may contain insects parts, indigestible plant matter, bones, fur, feathers, bills, claws, and teeth.