Pellet Formation Chart

Esophagus Glandular Stomach Muscular Stomach

Intestines

Pellet Formation

1.

Prey is positioned head-first in the beak.

Vent

Barn Owls do not have teeth to chew prey. Some large prey may be torn into smaller pieces before they are swallowed, but usually the Barn Owl will swallow them whole, in one bite. This is how Barn Owls eat shrews, mice, voles, and most rates.

Since owls do not have teeth, the bones cannot be ground into small pieces that pass through the body. Instead, the prey is completely broken apart by chemicals in the stomach called enzymes. Along with pressure from the stomach muscles, this separates the fleshy portions from the bone and hair.

Muscular parts in the stomach prevent the bones and hair from going any further, but they allow the digested, fleshy portions to enter the intestine. This is where the nutrients are collected and sent to the rest of the body. These nutrients include proteins, carbohydrates, vitamins, and water- all of the things that an owl needs to make energy and continue living.

3.

Prey enters the glandular stomach.

2.

Prey is swallowed and passes through the esophagus.

4.

Enzymes break down the prey and nutrients pass through the muscular stomach.

Some of the digested material that enters the intestine is not needed. This material, along with other waste collected throughout the body, is ejected from the vent. This pasty, white material is known as urea. It is very rich in nitrogen and is similar to urine in mammals, only thicker.

The bones and hair that were left in the stomach must also be expelled. This is done through the mouth. Since the bones are no longer surrounded by flesh, they could get stuck in the throat. To prevent this, the stomach packs the bones in the hair. This slick, soft package is then regurgitated as what we call an owl pellet.

6.

Waste is excreted through the vent.

5.

Nutrients are absorbed into the body from the intestine.

Hair is pressed around the bones of the prey.

The pellet is orally expelled.