vit
acti ies
34&35 Mystery Pellets
(Sessions I and II)
BROWARD COUNTY ELEMENTARY SCIENCE BENCHMARK PLAN
Grade 3—Quarter 4
Activities 34 & 35
SC.B.1.2.1
The student knows how to trace the flow of energy in a system (e.g., as in an ecosystem).
SC.B.2.2.1
The student knows that some source of energy is needed for organisms to stay alive and
grow.
SC.G.1.2.1
The student knows ways that plants, animals, and protists interact.
SC.G.1.2.5
The student knows that animals eat plants or other animals to acquire the energy they need
for survival.
SC.H.1.2.1
The student knows that it is important to keep accurate records and descriptions to provide
information and clues on causes of discrepancies in repeated experiments.
SC.H.1.2.2
The student knows that a successful method to explore the natural world is to observe and
record, and then analyze and communicate the results.
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SC.H.1.2.3
The student knows that to work collaboratively, all team members should be free to reach,
explain, and justify their own individual conclusions.
SC.H. 1.2.4
The student knows that to compare and contrast observations and results is an essential
skill in science.
SC.H.1.2.5
The student knows that a model of something is different from the real thing but can be
used to learn something about the real thing.
SC.H.3.2.2
The student knows that data are collected and interpreted in order to explain an event or
concept.
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ACTIVITY ASSESSMENT OPPORTUNITIES
The following suggestions are intended to help identify major concepts covered in the activity
that may need extra reinforcement. The goal is to provide opportunities to assess student
progress without creating the need for a separate, formal assessment session (or activity) for
each of the 40 hands-on activities at this grade level.
1. Session I—Activity 34: Review with students that they have studied flows of energy in the
world around them. Ask, How does finding small animal bones inside an owl pellet show
another type of energy flow? (One animal eats another to gain the energy to live.)
2. Session II—Activity 35: Ask, If the food chains you studied (from producer to consumer)
describe energy flow, what must the starting source for all this energy be? (sunlight, the
Sun) What other cycle or chain of energy flow that you studied this year also started with
sunlight? (the water cycle) Are you a producer or consumer in a food chain? (consumer)
Did your own personal food chain today start with sunlight? (Yes, if you ate plants directly.
Even if you ate another consumer, a plant must still have started the chain.)
3. Use the Activity Sheet(s) to assess student understanding of the major concepts in the
activity.
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activities 34 & 35 Mystery Pellets
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In addition to the above assessment suggestions, the questions in bold and tasks that
students perform throughout the activity provide opportunities to identify areas that may
require additional review before proceeding further with the activity.
vit
acti ies
34&35
Mystery Pellets
OBJECTIVES
Students examine owl pellets in an effort to
find out what they are. Then, based on
what they find, they decide how owls fit
into the food chain.
The students
For the class
1
1 roll
poster, Investigating Food Webs
with Owl Pellets
tape, masking
Delta Science Reader Food
Chains and Webs
*provided by the teacher
offer ideas about the contents and origin of
owl pellets
dissect pellets and identify bones found
within
construct food chains that include owls
SCHEDULE
Session I—Activity 34 About 45 minutes
Session II—Activity 35 About 45 minutes
VOCABULARY
dissect
food chain
pellet
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MATERIALS
For each student
1
1
Activity Sheet 34
Bone Identification Sheet
1 pair
gloves, disposable*
1 pair
safety goggles*
For each team of four
1
1
1 sheet
4
2 pairs
container, plastic, small, with lid
owl pellet
paper, white, 11 in. × 17 in.*
toothpicks
tweezers
PREPARATION
Session I—Activity 34
Make a copy of Activity Sheet 34 for each
student.
Session II—Activity 35
Make a copy of the Bone Identification
Sheet for each student.
BACKGROUND INFORMATION
Owls are predatory birds that fly and hunt
mostly at night. They range in size from the
tiny Elf Owl, which stands 13.5 cm (5.25 in.)
tall, to the majestic Great Gray Owl at 55 cm
(22 in.). The animals that owls prey upon vary
with the owl’s size and species, but mid-size
owls typically depend heavily upon mice,
voles, and other animals that are active
during the nighttime hours.
Owls swallow their prey whole. Once they
have extracted the food value from their
catch, they compress the uneaten bones and
fur of their prey into pellets, which they then
regurgitate.
Owls typically have a favorite roost—usually a
tree, where they spend most of their days
resting. An accumulation of owl pellets can
often be found on the ground under such trees.
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Since owls swallow their prey whole, each
pellet contains all the bones of one or more
prey animals, making it possible to both
identify the species of the prey animal and
to reconstruct its entire skeleton.
Activity Sheet 34
Mystery Pellets
Session I—Activity 34
1. Describe your mystery pellet.
Answers will vary. Possible answer: oval-shaped, dark
2. Draw your mystery pellet.
Drawings will vary.
3. Make a guess about what the mystery pellet is.
Answers will vary. Possible answer: waste matter from
an owl
4. List what you found inside your mystery pellet.
Answers will vary. Possible answer: bits of fur, tiny
bones, and gray dust
Session II—Activity 35
5. What is the mystery pellet?
Answers will vary. Possible answer: the digested
remains of a mouse that an owl swallowed whole,
then regurgitated as a compressed pellet
Guiding the Activity
Additional Information
Session I—Activity 34
Show students an owl pellet and tell them it
came from an animal. Ask, What do you
think this might be?
At this point, students are unlikely to know.
Do not tell them what the pellet is.
Write pellet on the board, and say that the
term pellet is used to refer to a small rounded
piece of a material. Explain that you will be
referring to these objects as “mystery
pellets,” for now.
Distribute a copy of Activity Sheet 34 and a
pair of disposable gloves to each student.
Distribute a pellet to each team of four. Tell
the students to examine their mystery pellets
closely, then describe and draw them on their
activity sheets.
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activities 34 & 35 Mystery Pellets
Make sure that students do not pry apart the
pellets at this time. They should simply
examine the outside of the pellets by turning
them over in their hands.
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1
Guiding the Activity
Additional Information
Next, have students write down their ideas of
what the mystery pellet might be.
2
When they have completed this, ask, What do
you think these mystery pellets might be?
Answers will vary.
Write all of their ideas on the board.
Ask, How might we learn more about the
pellets?
3
Students may suggest taking the pellets
apart to look inside. They may also suggest
doing research in nature resource books.
Write dissect on the board. Say that dissect
means to carefully take apart. Tell students
that they will be dissecting these mystery
pellets to learn more about them.
Distribute an 11-in. × 17-in. piece of paper,
two pairs of tweezers, and four toothpicks to
each team of four. Explain how to begin
dissecting the pellets (see Figure 34-1).
Students should lay down the paper on their
work surface and place the pellet on the
paper. They should then use the toothpicks
and tweezers to slowly pry the pellet apart,
being careful to save everything they find.
The pellet is composed of tiny bones, fur,
and a dust-like matrix.
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Circulate throughout the classroom, helping
the students to focus on their dissection and
discoveries. Have students complete
question 4 of the activity sheet.
About 10 minutes before the class is over,
distribute a plastic container with lid and a
piece of masking tape to each team of four.
Tell teams to write their names on the strip of
masking tape. Have students pack all of the
pieces of their pellets into the container and
label the container with their names.
4
Figure 34-1. Dissecting the owl pellet.
Ask, What did you find inside the pellets?
Students should have found bones of various
types, fur, and dust inside the pellet.
Ask, Does anyone want to make another
guess about what the pellets are?
Students are likely to say that the pellets
contain the remains of small animals and
probably are the waste product of a larger
animal.
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Guiding the Activity
Tell the students that the pellets are typically
found around the bases of trees where owls
roost during the day and are called owl
pellets. Display the Owl Pellets poster. Use
the diagrams in the center of the poster to
explain how the pellets are formed.
Ask, Whose bones and fur do you think
were in your pellets?
Additional Information
Owls swallow the animals they eat whole, but
cannot digest fur and bones. After digesting
the meat from the eaten animal, owls cough
up these compressed pellets of bones and fur.
the bones and fur of the animals that the
owls ate
Tell students that they will be looking at the
animal bones again in the next session.
Collect the toothpicks and tweezers, and
return them to the kit. Collect students’
activity sheets, paper sheets, and plastic
containers for use in Session II. Have
students wash their hands.
Session II—Activity 35
6
Review the origins of the owl pellets by
asking, How and why do owls create owl
pellets?
Tell students that because the owls swallow
these animals whole, each owl pellet
contains all the bones of at least one animal.
Some owl pellets will contain the bones of
more than one prey animal.
Distribute a copy of the Bone Identification
Sheet to each student. Review the parts of
the skeleton with students by asking, Where
is the skull in the drawing? Can you touch
your own skull?
Students should be able to do this.
Repeat the question for the leg bones, ribs,
backbone, and shoulder blade (scapula), and
have students touch these bones in the
illustration and on their own body each time.
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376
Owls swallow the animals they eat whole,
then cough up the indigestible bones and fur
that they cannot digest.
Redistribute four toothpicks, two pairs of
tweezers, an 11-in. × 17-in. piece of paper,
and the container with their partially
dissected owl pellet to each team of four.
Distribute disposable gloves to each student.
activities 34 & 35 Mystery Pellets
Demonstrate the location of bones on
yourself, as needed.
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5
Guiding the Activity
Additional Information
Have students use the tweezers and the
toothpicks to clean the fur off the bones
they find.
Challenge students to find and identify as
many of the bones shown in the Bone
Identification Sheet as possible.
When students have completed working with
the bones, have them place the bones in their
plastic containers and close the lids tightly.
8
Ask, What did the owls eat?
Have students complete their activity sheets.
Students may be able to recognize the skeleton
as that of a mouse (see Figure 35-1) or other
small rodent, such as one of those shown in
the grid on the Owl Pellets poster.
skull bones
neck vertebrae
shoulder blade (scapula)
back teeth
back vertebrae
upper leg
hip (ilium)
tail vertebrae
lower jaw
ribs
front teeth
upper leg
lower leg
paw bone
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front legs
lower leg
rear legs
Figure 35-1. A mouse skeleton.
Write mouse and then owl next to one
another on the board and ask, How should
we draw in an arrow to make this a food
chain?
Have a student volunteer draw the arrow for
you. Tell students that mice eat seeds and
grass. Ask, How can we add grass to this
food chain?
Students should suggest drawing an arrow
pointing from the mouse to the owl.
Write grass on the board to the left of mouse,
and draw an arrow pointing from the grass to
the mouse.
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Guiding the Activity
Ask, Which organism is a producer in this
food chain?
The grass is a producer because grass is a
plant.
Ask, Which animal is a primary consumer?
The mouse is a primary consumer because
it eats grass, a producer.
Ask, What do we call animals that eat other
animals?
Animals that eat other animals are called
secondary consumers.
Write grass
cricket
anole on the
board. Explain that sometimes owls eat
anoles, and challenge students to add an owl
to this food chain.
Ask, Why do the arrows point from the
organism being eaten to the organism that
is eating it?
The arrows show how energy is passed up
the food chain.
As appropriate, read or review pages 4–9 of
the Delta Science Reader Food Chains and
Webs.
REINFORCEMENT
Students may enjoy reassembling the
skeletons of the mice by gluing each bone
into its correct position on the illustration.
Copy the skeleton illustrations onto tagboard
or some other stiff paper, and supply
students with cotton swabs or paintbrushes
and white glue that has been slightly diluted.
SCIENCE JOURNALS
Have students place their completed activity
sheets in their science journals.
378
The food chain would look like this:
grass
cricket
anole
owl.
If needed, explain that an anole is a small
green lizard native to Florida and other
southern states. Students may know it as a
“chameleon.”
activities 34 & 35 Mystery Pellets
CLEANUP
Rinse and dry the plastic containers and
return them to the kit, along with the
tweezers. Recycle or dispose of the paper
and toothpicks. The students may wish to
take the remains of the owl pellets home or
save them for extension activities. Have
students wash their hands.
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8
Additional Information
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Connections
Science Extension
Science and Language Arts
In Greek mythology, Athena—the goddess
of wisdom—was symbolized as an owl and
was believed to take the form of an owl at
times. Students might enjoy reading myths
about Athena and other Greek gods,
goddesses, and demigods. They also may
be able to find photographs of ancient
Greek pottery and murals that depict
Athena as an owl.
Also encourage students to research more
recent folklore regarding owls as signs of
evil and messengers of doom. According to
some old legends, the hooting of an owl
warns of impending danger or someone’s
death. (Also see the third Science
Extension connection.)
Explain that owls eat many other types of
animals besides mice. Suggest that
students read about owls to find out what
other types of animals they eat. (Depending
on their size, where they live, and what is
available to them at different times of the
year, owls may eat rats, voles, shrews,
moles, rabbits, squirrels, chipmunks,
lizards, snakes, frogs, earthworms, snails,
spiders, insects, fish, and birds. Large owls
also eat smaller owls.) Students may have
found the remains of some of these animals
in their owl pellets—feathers or insect
casings, for example.
Also encourage students to find out what
animals eat owls—not only adult owls but
their eggs and owlets. Students will
discover that owls have relatively few
natural enemies. (Animals that prey on
owls include eagles and hawks. Snakes
and weasels, which can climb trees, prey
on owl eggs and young owlets in nests.)
Explain that because they have few natural
enemies, owls are most often the last
consumers in food chains.
Try to obtain a recording of different owl
calls. Students will see that the calls are
unlike the calls or songs of other birds and
can seem quite eerie and strange. As they
listen to the recording, tell students to close
their eyes and imagine that they are alone in
the woods late at night. (Also see the
second Science and Language Arts
connection.)
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activities 34 & 35 Mystery Pellets