What Are Owl Pellets?
Owls swallow tiny prey animals, such as mice, in one gulp—fur, bones and all. The indigestible fur and bones are packed together inside the owl’s stomach. Later, all this is spit out as a dry pellet. These pellets are good clues as to what owls eat.
Pellets are usually about as big as an adult thumb and they are often dissected by students and scientist to help them learn a bit about an owl’s lifestyle through careful examination of the pellet’s contents.
Owls are birds of prey. They feed on small mammals, birds and insects. And there are even a few that go fishing! Owls usually carry their food back to a favorite perch and eat it there. If you happen to find owl pellets under a tree, there’s a good possibility that an owl lives in that tree.
An owl pellet generally reaches its final form a few hours after the owl has eaten. However, the pellet is not usually ejected immediately after it is formed. Owls can store a pellet in a structure known as the proventriculus for as long as 20 hours before disgorging it.
Since the stored pellet partially blocks the entrance to the digestive system, it must be ejected before the owl can eat again. Young owls do not produce pellets until they have begun to eat their prey whole.
The actual process of regurgitating a pellet lasts from a few seconds to several minutes. The pellet is forced out by spasms of the owl’s esophagus. These spasms make the owl look like it is coughing painfully. However, it is not hurt by the process because the pellet remains soft and moist until it leaves the owl’s body.
The shape and texture of a given owl pellet depends on the species of the owl that produced it and the type of prey that the owl consumed. Some pellets are tightly compacted, oval, and furry. Others are loosely compacted with an irregular shape. Pellets are moist when they are first ejected, but quickly dry out and start to decompose once they leave the owl’s body.