Museum of Science, Boston

Owl Pellet Dissection at Different Ages

Books for Kids

  • Animal Lives - The Barn Owl
    , by
    Bert Kitchem
  • Owl Babies
    , by
    Martin Waddell & Patrick Benson
  • Owl Puke: Book and Owl Pellet
    , by
    Jane Hammerslough

Contact Us

Contact the Discovery Center and Living Lab staff at livinglab@mos.org

October 2013: Owl Pellet Dissection

Owl Pellet Dissection

Dissections are a great way for children to learn and practice their observation and classification skills, all while learning about animals that are quite different from themselves! During an Owl Pellet Dissection, children learn about how and what owls eat, as well as how a pellet is formed in an owl’s unique digestive system.

Children act as 'field biologists' as they dissect, analyze and identify the remains of various small animals found in the pellets. Even the youngest children can practice skills of observation and classification while using age-appropriate tools (including tweezers, picks, magnifying lenses and microscopes) to dissect an owl pellet.

While dissecting an owl pellet, children are encouraged to make observations about what they find, while sorting the bones and other materials found in the pellet. Children can then use a bone identification chart to try and identify the bones and other materials they find in order to discover what the owls ate - this will likely be their first lesson in comparative anatomy.

Owl Pellet Dissections at Home

You can continue your Owl Pellet explorations at home ...

Dissecting Owl Pellets at Home

Background
Owls leave behind pellets anywhere they've perched after a meal. You can search for pellets in wooded areas near your home- the best place to look is at the base of a tree where you've seen an owl perched before. However, while owl pellets can be found in the wild in many parts of New England (and maybe even in your yard!), we do not recommend dissecting owl pellets that you collect yourself in the wild. Pellets you collect on your own could be contaminated with small insects, bacteria or other organisms that use pellets as "home" after the owl has expelled it. The safest way to obtain pellets is to order them from a reputable company, such as Pellets Inc..

Once you've obtained your pellets, you will also want to gather some age-appropriate tools you can use for the dissection. Plastic tweezers, wooden toothpicks and a small magnifying glass are all very helpful tools to use when dissecting an owl pellet. An owl pellet identification chart will also aid you in your explorations. At the Discovery Center, we recommend that children wear goggles during this activity- in case the fur flies!

Dissecting the Pellet
1. Using your fingers, gently break the pellet open.
2. Using the tweezers and/or toothpicks, gently remove the fur from the pellet.
3. As fur is removed, you will also begin to see bones and other materials, which can be separated as you continue to dissect the pellet.
3. Try to identify the different bones - once you've identified a couple of bones, you may be able to determine what the owl ate (e.g. a rodent, mole, bird, or something else) using the owl pellet identification chart
4. Sort bones into groups, or attempt to build a skeleton using your discoveries!

What is an Owl Pellet?

Owls are carnivores (meat eaters), but, like all birds, they do not have teeth.

So in order for them to eat they must either swallow their food whole or tear it into large chunks with their beaks and claws before swallowing.

Owls cannot remove the meat from the bones, so the entire body of the prey animal is taken into the owl's body.

The owl’s prey goes into an organ called the proventriculus. Soon, digestive juices enter the proventiculus, dissolving the meat and other digestible materials (e.g. organs, skin, etc.) and allowing them to continue on to the stomach for further digestion. Meanwhile, the fur, feathers, bones and other indigestible material stays in the proventriculus, where muscle action compacts this material into a pellet.

The pellet stays in the proventriculus until the owl coughs it up. Once the pellet has been expelled, the owl can eat another meal!