How Owl Pellets are Made
All birds of prey consume quantities of bone, feathers, and fur when eating prey. Owls tend to swallow small prey such as voles, mice, and shrews whole. Their prey is swallowed headfirst and moves down the owl's esophagus and then through the proventriculus, which is the glandular part of the stomach. Here, the owl's food gets coated with digestive enzymes and then moves to the muscular part of the raptor’s digestive tract called the gizzard.
After the soft tissue has been digested, the remaining bones, fur, and/or feathers are rolled and compacted to form a pellet or casting. This pellet is regurgitated by the owl several hours after eating or before the next meal.
After the soft tissue has been digested, the remaining bones, fur, and/or feathers are rolled and compacted to form a pellet or casting. This pellet is regurgitated by the owl several hours after eating or before the next meal.
Accuracy in making counts of prey items depends on the type of pellet that is being worked with. Because of differences in feeding habits and physiology, hawks and owls produce pellets that differ in their ability to be examined quantitatively. Owls usually swallow small prey whole and don’t take the time to pluck their prey; however, their digestive tract causes little to no damage to the bones they consume. This process results in pellets that typically contain whole skeletons, which are relatively undamaged.
Hawks, on the other hand, pluck their prey before eating and then tear it into small pieces before swallowing, consuming varying amounts of fur and feathers. They also digest bones more completely than owls, so that their pellets often contain little osseous remains. Identification of prey species must be made by pairing incisors, which are usually present. Fairly accurate counts can be made in this manner by someone trained in their identification.
It isn’t known how many pellets a wild raptor produces per day, so accurate figures on daily intakes are unavailable; however, they do yield information as to the type of prey consumed. By comparing bones, feathers, and fur with the same material in a collection, identification of the dissected items is easy. In many cases, if a large enough sample of pellets is examined, it is possible to obtain a fairly accurate record of the diet of one raptor or the diet of a species. It is also an indication of population densities and vulnerability of the prey species identified, since prey is taken in proportion to its relative density.
Hawks, on the other hand, pluck their prey before eating and then tear it into small pieces before swallowing, consuming varying amounts of fur and feathers. They also digest bones more completely than owls, so that their pellets often contain little osseous remains. Identification of prey species must be made by pairing incisors, which are usually present. Fairly accurate counts can be made in this manner by someone trained in their identification.
It isn’t known how many pellets a wild raptor produces per day, so accurate figures on daily intakes are unavailable; however, they do yield information as to the type of prey consumed. By comparing bones, feathers, and fur with the same material in a collection, identification of the dissected items is easy. In many cases, if a large enough sample of pellets is examined, it is possible to obtain a fairly accurate record of the diet of one raptor or the diet of a species. It is also an indication of population densities and vulnerability of the prey species identified, since prey is taken in proportion to its relative density.
Owl Pellet Safety
Owl pellet dissection is a safe and rewarding activity that provides students with a laboratory experience that they will long remember. That’s why our pellets have been individually wrapped in foil and heat-sterilized at 350°F for 45 minutes to eliminate potentially harmful bacteria.