Down and Dirty with Owl Pellets
Whoooo has dissected an owl pellet? You may think they are gross or you may get excited about them. Either way, owl pellets are great visuals for students when studying the nature of food chains and in demonstrating the role of predators in the ecosystem. Scientists use them to discover characteristics about owls such as when they hunt, where they hunt, how much they eat, and if their diet changes with the season. All of these things can be determined from what is found in owl pellets.
Owls cannot chew to break down their food, nor do they have a crop (a bag-like organ that stores food after it is swallowed for later digestion). Their food travels from their mouth to a temporary digestive organ called the proventiculus and then passes to their muscular stomach, or gizzard, for chemical digestion of the prey's muscle, fat, skin and internal organs. The fur, bones, teeth, skulls, claws and feathers, however, are not digested by the gizzard and are too dangerous to pass through the owl's intestines. All of this has to go somewhere, so within a few hours of eating the prey, the owl's gizzard packs it into a compact pellet and regurgitates it. These regurgitated pellets are moist when they are first ejected, but they quickly dry out and start to decompose once they leave the owl's body. It is possible to find owl pellets out in the wild if you know what to look for. Keep in mind, owl pellets found in the wild have not been sterilized and contain bacteria. For classroom dissection studies, sterilized owl pellets are recommended and may be bought from a retailer.
Dissecting owl pellets requires a little bit of detective work and usually proves to be fun and exciting. Bones should be separated from the fur or feathers, and once all the bones are extracted, the detective work comes into play. In most owl pellet kits, there are instructions and bone identification sheets to help with the process of identification. If you buy individual pellets, Bone Sorting Sheets may also be purchased separately for students to use. By looking at the shapes of the bones, particularly the jawbones, you can tell what species of animal the owl has eaten. You will also be able to count how many prey items are contained within a pellet.
Owl pellet studies can be fun in the classroom. Students may be hesitant at first, but after you assure them what the pellets really are and how they are formed, most times they prove to be a little more eager to dissect one. If you have never dissected an owl pellet, or if you just want to have a little fun with or without your class, check out this Virtual Owl Pellet Dissection.