Rashida M - Owl Pellet Dissection

7th Grade Health Science Class, Lawrence Middle School
Lab Duration: 2 periods of 50 min each

Previous Lessons:
Students have been working on the human body systems and are currently learning about the skeletal system. They are familiar with some of the major bones of the body as well as the structure and function of the skeletal system.

Background: Owl pellets provide scientists with information regarding the owl’s diet over the past twenty-four hours. Since owls cannot digest the bones and fur of any animal it eats, it regurgitates (spits back) those remains in the form of a pellet. You can take a pellet apart and identify the bones and the species of small prey the owl has eaten.


Purpose: Examine the skeleton of a small animal and compare it to the human skeletal system.

California Content Standards Addressed:

5. b. Students know organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system

5. c. Students know how bones and muscles work together to provide a structural framework for movement.  

7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:

a. Select and use appropriate tools and technology (including calculators, computers, balances, spring scales, microscopes, and binoculars) to perform tests, collect data, and display data

c. Communicate the logical connection among hypotheses, science concepts, tests conducted, data collected, and conclusions drawn from the scientific evidence.

d. Construct scale models, maps, and appropriately labeled diagrams to communicate scientific knowledge (e.g., motion of Earth’s plates and cell structure).

Materials(1 per group of 2):

        Owl Pellet, Tweezers, Paper plate, Ruler, Balance


1)   Each group of 2 students will receive one owl pellet.

2)   What do you predict will be in the owl pellet?

3)   Record the following measurements of your owl pellet.

        Length(cm), Width(cm), Weight(g)

4)   Start taking apart the pellet. Write down any observations of what is inside. 

 5)   How many kinds of bones did you find? (use the bone sorting chart provided)

Skulls______Ribs______ Jaws ______ Pelvis ______ Shoulder blade ______ Humerus ______
Vertebrae _____ Ulna/Radius_____Femur_____ Scapula ______Tibia/Fibula ______

6)   Place your bones on a piece of paper and assemble the skeleton of the small animal. Did you find a complete skeleton? If not, why do you think you did not?


1)   Based on the bones you found, what animal do you think your skeleton is.

2) What are the similarities between the skeleton you put together and the human skeleton? 

List at least four.

Students may name the presence of bones that are similar(any of those listed above). They may also discuss the way the animals move and how it relates to humans.

3)   What are the differences? List at least three.

Students should note the difference in shapes of various bones including the skull, jaw, pelvis and scapula. They may also note the presence of tail vertebrae and differences in limbs and/or wings.

4)   Why might these similarities and differences exist?

Students should know that the similarities exist because of the similar functions such as movement and protection of body organs. The differences exist because of varying functions such as incisors for gnawing and wings for flying.


1.    http://www.eagle-bluff.org/Owl%20Pellets.pdf

2.    http://www.kidwings.com/teacher/owlpellets/bonechart.htm

3.    www.sciencea2z.com/z_courses/Lisa_Owl.doc

4.    http://www.mbr-pwrc.usgs.gov/id/framlst/Song/h3650so.mp3

5.    https://sites.google.com/site/sed555s/555f10-presentations/owl-pellet-lab-a-skeletal-system-study


Norman Herr,
Mar 31, 2011, 1:41 PM
Norman Herr,
Mar 31, 2011, 1:13 PM
Norman Herr,
Mar 31, 2011, 1:30 PM
Norman Herr,
Mar 31, 2011, 11:37 AM