Birds and Mammals

1
Birds and Mammals
2
____ are fluffy, insulating feathers that help
keep birds warm.

• Down feathers

3
A birds streamlined body surface is the result of

• contour feathers.

4
Why do birds spread oil on their feathers?

• The oil makes the feathers water repellent.

5
What will a bird do if it needs to cool off?

• Lay its feathers flat and pant like a dog.

6
What must birds do to get the energy they need?

• Birds eat large amounts of food in proportion to
  their body weight.

7
In small birds, the heart beats about 1,000 times
per minute. This is necessary because of their
high

• metabolism.

8
Lift

• is the upward force on a wing that keeps a bird
  in the air.

9
To produce lift, the air flowing over the top of
the wing has to travel _____ than the air flowing
underneath the wing.

• farther and faster

10
To survive long, harsh winters, many birds

• migrate.

11
Humans are classified as

• mammals.

12
Mammals that lay eggs are called

• monotremes.

13
Mammals with pouches are called

• marsupials.