Owl Pellet Dissection

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DIY Experiment Series Asks: What's in an owl pellet?

The "How To" From Science-U

You Will Need

Warning: Pellets are sterilized prior to shipment, but they have been known to still harbor salmonella (and other) bacteria. Sterilize area and wash hands after lab.

  • Gloves
  • Tweezers
  • Toothpicks
  • Construction paper

Directions

1. Measure the length and width of your owl pellets. Take the mass of your owl pellet.

2. Carefully examine the exterior of the pellet. Write down your observations.

3. Carefully use a toothpick to break apart the owl pellet and observe what is inside. Use a toothpick to expose the bones for identification.

4. Use a dissection chart, like the one found here from Carolina Biological Supply Company, to identify the animal bones.

5. Organize the bones into groups and label them. You can use construction paper as a place to mount them.

Owl pellet chart

Make sure to wear protective gear when dissecting!

For educators and parents - How to guide young learners in science:

  • Inquiry-based learning (IBL) is a teaching approach that is fundamental for the development of higher order thinking skills (summarizing, analyzing, evaluating, creating). It puts the student in the driver's seat and promotes learning through engaging student-based investigations, following the same process used by scientists.
  • IBL begins by posing a question, problem, or scenario rather than simply presenting facts or a standard method to solve a problem. The learner is actively engaged and investigates concepts to reach authentic meaning.
  • The IBL process can vary, however the basics are as follows:

1. The student creates a testable question of their own.

2. The student obtains supporting evidence to answer the question by making observations, doing research, collecting data through an experiment, changing variables from a previous experiment, etc.

3. The student explains the evidence collected.

4. The student creates a claim (explanation) and justifies it using evidence form the investigation.

5. The student creates predictions for future investigations.

  • Recording information during the IBL process is also important to promote science literacy. The following chart is a helpful tool to guide students through the process.

Guided inquiry map

Questions to ask:

  • While examining the outside of the pellet, do you see any signs of fur? Any signs of feathers? Why might you see these things?
  • What do we know about the digestive system of an owl based upon the pellets?
  • What do we know about the diet of this particular owl based upon the pellets?
  • What kind of animals do you think are found in the owl's ecosystem?
  • Other types of birds form pellets. What would you expect to find in the pellets of other birds, like a seagull?
  • Owls, hawks, and eagles are types of raptors, animals which have hooked beaks and sharp claws, and are therefore adapted for seizing prey animals. Hawks and eagles differ from owls in that they eat their prey animals by tearing them into small pieces, picking out the flesh and avoiding most of the fur and bones. They also have strong stomachs which can digest most of the bone material which they might eat. The relatively small amount of indigestible bone and fur that remain will be compacted by their stomach muscles into a pellet similar to the owl's. Do you think an eagle pellet would be as useful for dissecting as an owl's? Why or why not?
  • Construct a diagram of a food web (of at least 5 animals) with an owl at the uppermost trophic level. Use an arrow to show which organism in the consumer or predator.

The science behind it:

  • Owl pellets are masses of bone, hair, teeth, and feathers of various animals consumed by the owl. Pellets are produce and regurgitated by owls, hawks, eagles, and other raptors that swallow their prey whole or in large pieces. Owls eat early in the evening and regurgitate a single pellet approximately 20 hours later.
  • Owls do not have strong digestive enzymes in their stomachs, so the parts of their meal go undigested and form into wet, slimy pellets with even the most fragile bones preserved unbroken.

Resources:

  • Teaching Great Lakes Science (http://www.miseagrant.umich.edu/lessons/teacher-tools/guided-inquiry-process/)
  • Biologycorner.com (http://www.biologycorner.com/worksheets/owlpellet.html)
  • The Notebooking Fairy (http://notebookingfairy.com/2011/11/owl-pellet-dissection-notebooking-page/)
  • Special thanks to The Raptor Center at Shaver's Creek Environmental Center and Wild owl footage, courtesy of Justin Hoffman!
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