Grades
4–5
Unit 6
Adventures
With Otters
Otter Versus Otter
bit.ly/toptalentepi6
Which animal is Georgia Aquarium’s top talent? You
decide! It’s otter against otter before a panel of three
penguin judges as sea otters and an Asian small-clawed
otter demonstrate social behavior and eating habits.
These amazing animals provide an “otter-ly” chaotic
competition in the “Aquarium’s Top Talent” video
presented by Georgia-Pacific.
Next Generation Science Standard:
Structure and Function, 4-LS1-1
Plants and animals have both internal and external structures that serve various functions in
growth, survival, behavior and reproduction. Both the sea otter and Asian small-clawed otter have
structures to help them survive. These playful animals have streamlined bodies that make them
strong swimmers. They eat about a quarter of their weight every day to fuel their bodies, which is
one way they keep warm. When they dive beneath the surface,
their hearts slow and they close their noses and
ear canals. The sea otter actually uses rocks
as tools to break open shellfish for food.
WORDS TO KNOW
grooming: to clean and keep up the appearance
social: living or growing in groups or communities
solitary: growing or living alone
INTRODUCING THE LESSON:
1. Write the following sentence on the board: I am known for doing a lot of _____ing, ______ing,
___ing and ______ ing.” Have each student write on scrap paper four verbs ending in -ing to
describe actions he often takes, such as reading, snacking, talking and running.
2. Provide time for students to share their verbs. Then announce that if you were an otter, you
would say “I am known for doing a lot of grooming, eating, playing and swimming.” Then
explain to students that they’ll be learning about two special members of the otter species: the
sea otter and the Asian small-clawed otter. Tell them that the sea otter, from the North Pacific
Ocean, is solitary and spends all its time in the water. The Asian small-clawed otter is social and
lives in family groups. The smallest type of otter, it spends only about half its day swimming,
because its small body loses heat easily in the water. Both types of otter spend much of their
time grooming, eating and playing.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Grades
4–5
Adventures
With Otters
Designed “Fur”
Warmth
Next Generation Science Standard:
Structure and Function, 4-LS1-1; Information
Processing, 4-LS1-2
Plants and animals have both internal and external
structures that serve various functions in growth, survival,
behavior and reproduction. Different sense receptors are
specialized for particular kinds of information, which may
then be processed by the animal’s brain.
ESTIMATED LESSON TIME: 20–30 minutes
MATERIALS:
4 balloons
2 large cups
ice water
ruler
Background Information:
Otters have two layers of fur. A thick layer of fine underfur traps air next to an otter’s skin.
This insulates the otter from cold water temperatures. Thicker guard hairs form a waterproof
topcoat. Sea otters use their whiskers to sense
changes in the water current and to find food.
The stiff hair on Asian small-clawed otters’
WORDS TO KNOW
snouts and elbows also helps them locate
dense: thick
prey and sense water turbulence.
insulate: to prevent the transfer of heat
turbulence: in a state of being disrupted
underfur: the thick, soft layer of fur beneath
the longer, coarser hair of a mammal
Lesson:
1. Have each student use a ruler to draw a one-inch square. Next, have the student draw
lines (hairs) on the square inch. Direct her to count the hairs she drew and write the
number beside her drawing.
2. Explain to students that otters have double-layered coats of fur. Tell them that the
sea otter’s underfur—with up to one million hairs per square inch—is the densest
fur in the animal kingdom. Have students look at their square inches and compare
their numbers to one million. To give even more perspective, share that the average
human has about 100,000 hairs on his entire head.
3. Explain that the sea otter’s fur traps a layer of air against the otter’s skin. To show
how air insulates the animal from cold water temperatures, have student partners
complete the experiment steps.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Grades
4–5
Adventures
With Otters
EXPERIMENT STEPS
1. Fill both cups with ice water.
2. With your partner’s help, slip a balloon halfway up one index finger. Make sure the
balloon fits tightly around your finger. Then slightly inflate the second balloon and
have your partner help you slip it halfway up the index finger on your other hand.
3. Place each finger covered by a balloon in a different glass of water. Determine which
finger feels warmer: the finger covered by the deflated balloon or the one with the
slightly inflated balloon.
4. After all students have completed the experiment steps, ask which finger felt warmer and invite
them to consider why it felt warmer. (Students should report that the finger covered by the
slightly inflated balloon felt warmer. The air in this balloon insulated the finger from the cold
better than the uninflated balloon did.)
5. Help students realize that a layer of air in an otter’s fur insulates the otter’s body from the
cold just as the air in the balloon insulated their fingers. Explain that, to protect its insulating
qualities, an otter spends quite a bit of time cleaning its fur every day. In fact, some sea otters
spend as much as half a day grooming, cleaning their fur after eating by rolling in the water and
rubbing it with their paws and then fluffing it with air bubbles.
6. As a follow-up, have students research other ways that sea otters and Asian small-clawed otters
have adapted to survive in their different environments.
DID YOU KNOW?
Although they don’t use tools like sea
otters do, Asian short-claw otters sometimes
carry small pebble “toys” in their armpits.
When they’re playing, they juggle the pebbles
with their paws!
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Sea otters are an indicator species. They
eat animals that are filter feeders. Filter
feeders may collect toxins, such as those
from pollution, in their systems. They
pass these toxins on to sea otters. If the
sea otter population isn’t doing well, it
shows there is a problem in the habitat.
Sea otters are an important keystone
species in a kelp forest. Kelp is a type of
seaweed. Sea urchins eat kelp, and sea
otters eat sea urchins. This keeps the sea
urchin population from growing so large
that it destroys the habitat.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Bonus: Design a poster to encourage others to protect sea otters.
Use the information in the chart to help you.
_______________
indicator species: any plant or
animal that can show the health of an
ecosystem. When an indicator species
is doing well, it means the ecosystem
is healthy. If the species dies or moves
away, it means the ecosystem has
problems.
_______________
keystone species: any plant or animal
that is important for the survival of other
living things in an ecosystem
Read the information in the chart.
Then read each statement on the right.
Write each statement’s letter in the chart to show
whether it is an example of a keystone species
or an indicator species.
f. Snails eat algae. If there is a great deal of water
pollution, algae won’t grow. If a snail population in a
habitat is large, scientists know that there is plenty
of algae and that the water quality is good.
e. Elephants live on Africa’s savannas, or grasslands.
They feed on the trees there. If they did not, too
many trees could grow and destroy the grasslands
for many different species.
d. Dragonflies buzz around wetlands, eating other
insects. If dragonflies disappear, it shows there is a
problem with the wetland.
c. Mangrove trees grow in some wetlands. Their large
roots provide a place for many species to lay eggs.
Birds, manatees, fish and crustaceans feed among
the roots. If mangrove trees were to disappear, the
swamps would not exist.
b. When a beaver builds a dam that blocks a stream,
the overflowing water can change a dry stream
bank into a wetland. This creates a new habitat
for other species, such as dragonflies, herons and
frogs.
a. Alligators live in swamps in the southern United
States. They use their snouts and tails to dig holes
to live in. During dry periods, these holes are often
the only areas that still have water. Species such
as frogs, insects, fish and crustaceans move in with
the alligator so they can survive the drought.
Two Special Types of Species
Interdependence in ecosystems (5-LS2-1)
NameDate
ADVENTURES WITH OTTERS
Two Special Types of Species
ANSWER KEY
keystone species: a, b, c, e
indicator species: d, f
Bonus: Answers will vary.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Sea otter
Structure and function (4-LS1-1)
_____________________________________________
_________________________________________________________
5. Name two things both types of otters have in common.
_________________________________________________________
4. What characteristic makes the Asian small-clawed otter different
from most otters?__________________________________________
_________________________________________________________
3. Why do sea otters float with their feet out of the water?____________
2. Sea otters float together in small groups called __________________
while Asian small-clawed otters live in groups called
__________________.
1. True or false? Otters’ bodies are adapted for swimming. ___________
Answer the questions.
Asian small-clawed otters form strong
family ties. They live with at least a dozen
other otters. These groups are called
lodges. Males and females mate for life.
Both types of otters communicate by
growling, snarling, cooing, whistling and
other sounds. Each sound has a special
meaning, like an alarm or a greeting.
Playfulness is another common trait. Both
types of otters have been seen sliding
Asian small-clawed otters
down embankments over and over!
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
How They Socialize
Sea otters float in small groups called rafts. Females stick together
and avoid males except when mating. Sea otters rest on their backs
and wrap themselves in kelp to keep from floating away. They stick
all four feet out of the water, which
looks comical. Actually, their
feet have little or no fur, so heat
escapes quickly. Holding them out
of the water keeps the otters’ body
temperature normal.
Where They Live
Sea otters live in shallow waters along the northern Pacific coast.
Most of them are in Alaska. They rarely leave the water and live in
forests of giant kelp, a type of seaweed. Asian small-clawed otters
are found in India, China, Indonesia and the Philippines. Besides the
ocean, they also live in ponds, lakes, rivers, swamps and even rice
fields. They spend more time on land than most otters. They burrow
into muddy banks and make homes there.
Sea otters and Asian small-clawed otters have a lot in common.
For example, they both have webbed feet and long bodies that are
perfect for swimming. They also have very thick fur that keeps them
warm. These two animals also have some interesting differences, like
their size. Sea otters are the heavyweights in the otter family. Males
can reach 90 pounds. Asian small-clawed otters are the smallest
otters. They weigh up to 11 pounds. Read on to learn more.
Otters Big and Small
NameDate
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
1. true
2. rafts, lodges
3. Keeping their feet out of the water helps keep
their body temperature normal.
4. They spend more time on land than most otters.
5. Possible answers include that they both have
thick fur, have webbed feet and long bodies, live
in groups, make sounds to communicate, and
are playful.
ANSWER KEY
ADVENTURES WITH OTTERS
Otters Big and Small