Owl Pellet Evidence
We have been learning about many different animal food
chains. Now we are going to observe and investigate owl
pellets. What kind of evidence do you think can be found in an
owl pellet to help us know more about the food chain of which
the barn owl is a part?
Part 1
• Study the external features of the owl pellet. Based on your
observations, make a prediction about what you think you
might find inside your owl pellet.
• Carefully open the owl pellet, gently pulling the bones away
from the fur and other material in the pellet.
• Sort the bones by type. Draw each type of bone and show
the number of each type. Use a sorting sheet to identify the
types of bones you found.
Part 2
• Based on your findings in the owl pellet, draw a picture to
show the food chain that consists of the owl and its prey.
Be sure to include components that were a part of the food
chain in the owl's natural environment.
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• Infer what would happen to the population of mice, voles,
shrews, etc., if a large number of owls were to disappear
because their habitats were destroyed. Write a paragraph
to explain how this might affect other animals and/or plants
in the world, including humans.
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Owl Pellet Evidence
Suggested Grade Span
3–5
Task
We have been learning about many different animal food chains. Now we are going to observe
and investigate owl pellets. What kind of evidence do you think can be found in an owl pellet to
help us know more about the food chain of which the barn owl is a part?
Part 1
• Study the external features of the owl pellet. Based on your observations, make a
prediction about what you think you might find inside your owl pellet.
• Carefully open the owl pellet, gently pulling the bones away from the fur and other material
in the pellet.
• Sort the bones by type. Draw each type of bone and show the number of each type. Use a
sorting sheet to identify the types of bones you found.
Part 2
• Based on your findings in the owl pellet, draw a picture to show the food chain that consists
of the owl and its prey. Be sure to include components that were a part of the food chain in
the owl's natural environment.
• Infer what would happen to the population of mice, voles, shrews, etc., if a large number of
owls were to disappear because their habitats were destroyed. Write a paragraph to
explain how this might affect other animals and/or plants in the world, including humans.
Big Ideas and Unifying Concepts
Cause and effect
Form and function
Interdependence
Systems
Life Science Concepts
Populations and ecosystems
Structure and function
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Physical Science Concept
Transfer and transformation of energy
Science in Personal and Societal Perspectives Concept
Population, resources, environments
Mathematics Concepts
Data collection, organization and analysis
Diagrams
Measurement
Time Required for the Task
Two hours or more.
Context
After studying numerous examples of food chains and plant/animal relationships, students
investigated the contents of an owl pellet. This highly engaging activity can be used as an
assessment of a student's ability to recognize and formulate a food chain from evidence
collected from the pellet. Complete understanding of a food chain concept will be shown when
the student is able to show the source of energy for the food chain (the sun) and the producers
(plants) that were the food for the mice, voles and other creatures found in the pellet. If students
have studied decomposers, then this component may be added to the completed food chain.
What the Task Accomplishes
In this task, students are given the opportunity to show the structure of a food chain based on
evidence from the dissection of an owl pellet. Although they have only minimal information
(based on what's in the owl pellet) they should be able to infer other components of the food
chain (sources of energy, plants, decomposers, etc.) as they existed in the natural environment.
Students will also be able to predict what would happen should owls be taken out of the food
chain and how this might impact the natural world as a whole.
How the Student Will Investigate
Students will work in small groups of two or three to observe and investigate the contents of an
owl pellet. Students will sort and identify the bones found in the owl pellet and create a food
chain of the owl and its prey. Students will then infer what would happen if owls were not a part
of the food chain and the impact this would have on the natural world.
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Interdisciplinary Links and Extensions
Language Arts
Here are some related children's books, both fiction and nonfiction to share with students:
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Everybody's Somebody's Lunch, by Cherie Mason
Owl Moon, by Jane Yolan
There's an Owl in the Shower, by Jean Craighead George
Owls, by Sandra Markle
The Wonder of Owls, by Amy Bauman
Snowy, The Barn Owl, by Jane Burton
Otus: The Story of a Screech Owl, by Robert McClung
Science
An important aspect of the scientific method is finding evidence to support a position or to
answer a question. Often only partial evidence is actually found and the scientist must make
inferences about the "big picture." The inferences are tentative until more evidence is found.
This is the nature of science.
Students can research and investigate other food chains during this unit so that they
understand that all organisms are part of food chains. They can also begin to learn about the
idea of food webs and their role in the natural world and how food chains make up these webs.
Students can begin to recognize the human species' role in food chains and webs as well.
Mathematics
Students can measure and weigh the bones that they find if appropriate tools are available for
this as some of the bones are quite tiny. They can also compare the size of these bones to
other animals as well as to themselves.
Teaching Tips and Guiding Questions
Teachers may wish to design a checklist for observing science behavior during this task, such
as using tools appropriately. Teachers can ask students to define what these behaviors look
like in advance. Observe students carefully as they sort and classify bones, as this may not be
apparent through the answers on the data sheet.
Some possible guiding questions to ask students:
• What do you observe about the pellet? Do you notice anything about its shape? the
material it is made from?
• What do you predict will be inside the owl pellet? Why do you predict that?
• How will you open the owl pellet? Why do you think it might be important to open it
carefully?
• What do you observe about the contents of the owl pellet?
• How will you sort the contents? What do the items have in common? How are they
different?
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How can you use this information to create a food chain with an owl and its prey?
What are the important components of a food chain? How can you show these?
Why is the owl important in this food chain?
What happens if the owl is not in this food chain?
Concepts to be Assessed
(Unifying concepts and big ideas and science concepts to be assessed using the Exemplars
Science Rubric under the criterion: Science Concepts and Related Content)
Life Science – Structure and Function; Populations and Ecosystems: Students identify
characteristics of organisms, categorizing living things as producers, consumers or
decomposers. Students describe the interdependence of plants and animals in food chains and
determine the role of plant producers, consumers and decomposers in the food chain.
Science in Personal and Societal Perspectives – Populations, Resources and
Environments: Students recognize that human activities have an impact on natural systems
and that changing human behaviors can lessen the impact on ecosystems.
Physical Science – Transfer and Transformation of Energy: Students recognize that the sun
is the major source of energy in food chains and webs.
Mathematics: Students use diagrams and precise measurements. Students collect, organize
and analyze data appropriately.
Skills to be Developed
(Science process skills to be assessed using the Exemplars Science Rubric under the criteria:
Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)
Scientific Method: Observing, predicting, sorting, identifying, recording observations and data,
using tools, using data to construct a reasonable explanation, drawing conclusions, making
inferences, communicating findings and challenging misconceptions.
Other Science Standards and Concepts Addressed
Scientific Method: Students describe, predict, investigate and explain phenomena.
Scientific Theory: Students look for evidence that explains why things happen and modify
explanations when new observations are made.
Life Science – Structure and Function; Regulation and Behavior; Populations and
Ecosystems: Students describe and group animals by what they eat and where they live.
Students understand that living things are found almost everywhere in the world and are
interdependent.
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Communication: Students use verbal and nonverbal skills to express themselves effectively.
Suggested Materials
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One owl pellet per student or group of students
Tweezers and/or probe
Magnifying glasses
Paper towels
Egg carton for sorting (optional)
Bone sorting sheet (usually comes with owl pellet kits)
Data sheet
Possible Solutions
Food chain drawings will vary with the findings in the owl pellets. In all cases, the food chains
should show the sun providing energy for the system; plants as food for the voles, mice, birds,
or other small creatures that are found in the owl pellet; the primary consumer (based on
evidence) found in the pellet; and the owl as the top predator.
If the population of owls were to diminish, there would be an abundance of mice, voles, shrews,
etc., which in turn would consume larger amounts of plant material and could become "pests" to
crops. The number of primary consumers that could exist would depend on the availability of
food. Some students may say that more small animals would be available for other secondary
consumers, such as cats and hawks, which would increase their populations over time, thus reestablishing the balance in the environment. There are other explanations; and the important
consideration is that the explanation should be logical and based upon whatever information is
known by the student.
Task-Specific Assessment Notes
Novice
The drawing of the food chain is inaccurate – arrows are reversed and relationships are not
clear. The student uses tools appropriately, but does not separate all of the bones. The student
does not use the sorting sheet or give any conclusions or explanations. No terminology is used
to demonstrate an understanding of food chains and the relationships in a food chain. There is
no evidence of understanding the concept of interdependence and what happens when one
part of the system is removed.
Apprentice
The drawing of the food chain is basic, but clear and accurate. The student uses tools
appropriately. A sorting sheet is used. A conclusion and explanations are given, but the student
does not elaborate on ideas stated. A limited terminology is used to demonstrate an
understanding of food chains and the relationships in a food chain. There is no evidence of
understanding the concept of interdependence and what happens when one part of the system
is removed.
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Practitioner
The drawing of the food chain is clear and accurate. It shows how components are connected,
and each is well-labeled. The student uses tools appropriately. A sorting sheet is used. A
conclusion and explanation are given and shows how balance is important in an ecosystem.
The student uses appropriate terminology to demonstrate an understanding of food chains and
the relationships in a food chain. There is some evidence of understanding the concept of
interdependence and what happens when one part of the system is removed.
Expert
The drawing of the food chain is clear and accurate. It is a more complex food chain and is welllabeled. The student uses tools appropriately. A sorting sheet is used. The conclusion and
explanations are thorough and show the impact on humans. The student uses appropriate
terminology to demonstrate an understanding of food chains and the relationships in a food
chain. There is evidence of understanding the concept of interdependence and what happens
when one part of the system is removed.
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Novice
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Novice
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Apprentice
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Apprentice
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Practitioner
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Practitioner
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Expert
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Expert
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