Lesson 2
How Do the Behaviors of Animals Help Them
Meet Their Needs?
Fast Fact
Whale Song Some people call beluga whales the canaries of the sea. A beluga's song
can be heard above the water! Young belugas learn how to survive by watching
adult belugas. In the Investigate, you will see if a goldfish has the ability to learn.
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Train a Fish
Materials
 goldfish in a bowl
 goldfish food
Procedure
1. Work in a group of three or four classmates to train a goldfish. On the first day,
observe the behavior of the fish when you hold your hand above the bowl. Then
feed the fish by dropping some food into the bowl. Record the fish's behavior.
2. The next day, hold your hand a little closer above the bowl. Then drop the pellets.
Record the fish's behavior.
3. Each day, repeat Step 2, moving your hand nearer the water.
4. Use your observations to plan how to continue the experiment.
Draw Conclusions
1. From your observations, what can you infer about a fish's ability to learn?
2. Inquiry Skill When scientists experiment, they design procedures to gather data.
How did observing the fish help you plan the experiment?
Investigate Further
Observe a pet's behavior. List things that the pet does that no one taught it to do.
Also list things it may have learned.
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Reading in Science
VOCABULARY
instincts p. 106
hibernation p. 107
migration p. 108
learned behavior p. 110
SCIENCE CONCEPTS
 how instinctive behaviors help animals meet their needs
 how learned behaviors help animals meet their needs
READING FOCUS SKILL
MAIN IDEA AND DETAILS Look for ways animals fill their basic needs.
Main Idea
detail detail detail
Instincts
When you were born, you already knew how to suck to get milk. You knew how to cry.
Animals already know things, too. A spider knows how to spin a web to catch food.
Some animals, like zebras, know that living together in herds helps protect them
from predators. Some animals know how to protect themselves from the weather.
All of these behaviors are instincts—behaviors that animals begin life with that
help them meet their needs.
MAIN IDEA AND DETAILS What are some instinctive behaviors?
---see pictures
Orb-weaver spiders spin new webs every night. Each kind of spider begins life
knowing the pattern for its own kind of web.
A Weaverbirds build complex nests from grasses and other materials. They hatch
knowing how to weave their nests.
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Hibernation
Some animals live where winters are very cold. Many of them know by instinct how to
get ready for winter. First, they eat more food than normal, so they can gain fat.
Then, they find dens or build shelters. When the days become short and cold, the
animals move to shelters. They enter a dormant, inactive state called hibernation
(hy•ber•NAy•shuhn). Normal body activities slow. The heart barely beats, and
breathing almost stops. The body temperature drops to just above freezing.
Since the body is barely working, a hibernating animal doesn't use much energy and
doesn't need to eat. There is enough fat stored in the animal's body to keep it alive
through the winter. By springtime, hibernating animals are thin. They are very
hungry!
MAIN IDEA AND DETAILS Why do some animals hibernate?
---see pictures
Some turtles hibernate in winter. They don't breathe, but they get oxygen from
special cells inside their tail openings.
When the weather is cold, koi fish hibernate at the bottom of a pond.
A bat's normal heartbeat rate is 400 beats per minute. When the bat hibernates, its
heart beats 11 to 25 times per minute.
A woodchuck digs a winter burrow. Its body temperature drops from 36°C (97°F)
to less than 8°C (47°F).
Some male frogs hibernate at the bottom of ponds. The female frogs and their
young stay in holes or dens on land.
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Migration
Every year, people gather to watch whales. People also like to watch caribou travel. It's
possible to predict when to watch whales and caribou. These animals travel every
year at about the same time.
Migrate means "to move from one region to another." When animals regularly move as
a group from one region to another and back, it's a migration. Animal migrations
can depend on seasons or on other factors.
Migration is an instinctive behavior. Generally, animals migrate to a place that has more
food and a better climate. Some migrations are puzzling. For example, young
salmon go out to sea. They return to lay eggs in the mountain stream where they
were hatched.
MAIN IDEA AND DETAILS How do animals know when to migrate?
---see graph
Math in Science
Interpret Data
Science Up Close
Animal Migration Routes
---see pictures
Gray whales feed in cold northern waters in winter and travel south in summer to
look for mates and to give birth.
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Caribou spend the winter in forests in northern Canada. Then, in early spring,
they move north.
The sandpiper spends summers in eastern Canada. In winter, it flies nonstop over
the Atlantic to South America.
The arctic tern travels farther than any other animal. It breeds in the summer,
north of the Arctic Circle. In fall, it migrates to the Antarctic ice packs.
For more links and activities, go to www.hspscience.com
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Learned Behaviors
Many animals have only instinctive behaviors to help them meet their needs. But some
animals also have learned behaviors. What instincts did you have when you were
born? Did you have to learn how to eat, drink, and sleep? What behaviors have you
learned? You learned to walk and feed yourself. Now you can talk, write, and play
sports. Most of your behaviors are learned. Who helped you learn these things?
Older animals usually teach young animals learned behaviors.
Most mammals raise their young. Mammal mothers usually teach their young how to
get food and how to protect themselves. Among some animals, both parents care
for and teach their young.
Some animals can be trained to change their behaviors. Dogs often instinctively bark at
strangers, but people can train them not to do so. Horses are trained to respond to
their riders. These are learned behaviors.
MAIN IDEA AND DETAILS What are some behaviors that bears learn?
Robins are ready to leave the nest two weeks after hatching. Then the parents
teach them how to fly.
Bear cubs learn to climb trees when they are about six months old. The mother
sends them up a tree for safety.
Tiger cubs imitate their mother's every move while she hunts. They learn from her
example.
Insta-Lab
Learn How Make a list of behaviors you have learned in order to meet your basic
needs. Compare your list with a classmate's. Why do you think humans have many
more learned behaviors than most other animals?
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1. MAIN IDEA AND DETAILS Copy and complete this graphic organizer.
---see chart
2. SUMMARIZE Use the graphic organizer to write a paragraph in which you
summarize how animals meet their basic needs.
3. DRAW CONCLUSIONS Does a butterfly meet its basic needs by instinct or by
learned behavior? What leads you to your conclusion?
4. VOCABULARY Write a paragraph, using all the vocabulary terms from this lesson.
Test Prep
5. Critical Thinking Why would you not feed koi in a pond in winter?
6. Why does a hibernating animal's temperature drop?
A. to gain energy
C. to protect its young
B. to provide food
D. to conserve energy
Writing
Narrative Writing
Choose an animal that migrates. Research its migration path. Then write a story about
its migration.
Math
Multiply Whole Numbers
A gray whale eats for only four months of the year. Then it eats 300 kilograms (660 lb)
of food each day. How many pounds of food does it eat in one week?
Health
Basic Needs
Make a list of behaviors you have learned to keep yourself healthy and meet your basic
needs.
For more links and activities, go to www.hspscience.com
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