1. Chapter 18 Birds and Mammals

2. Section 1 Warm-blooded, Cold-blooded
If an animal regulates its body temperature by internal means then it is considered a warm-blooded creature.
Mammals and birds are the only warm-blooded animals. They maintain a relatively constant body temperature. Most are between degrees F. -

3. Ways Mammals and Birds Keep Temperature Normal at all Times
Fur or thick layer of feathers that insulate bodies
Small ears that prevent body heat from leaving
Blood vessels in skin can expand to cool blood
Sweat…as sweat evaporates it cools skin
Dogs mouth and throat contain many blood vessels that help cool the blood
Dogs, birds, and other animals pant to keep cool

4. Cold-blooded Animals
Fish, amphibians, reptiles worms, arthropods can not control their temperature internally.
Their body temperature is the same as their surroundings.
If cold-they become sluggish or inactive
Snakes often sun in the morning, then hide under rocks in the hot afternoons
Butterflies often flap wings in the morning to warm up enough to be able to fly
Worms come out of their burrows only in the evening or night to avoid the hot sun. In winter they burrow much deeper to stay warm.
Frogs often only come out early in the morning or late at night to avoid the hot sun

5. An advantage of being warm-blooded:
Can be active regardless of the temperature of the environment.
But, the warm-blooded animals must eat much more food to supply the energy required to maintain its temperature.

6. Section 2 Birds
Birds are warm-blooded vertebrates that have wings and feathers.
Found on every continent
Eat: insects, fish, fruit, mice, nectar, seeds, and worms
Do not have teeth: beaks and feet are designed to help them catch and eat their prey.
Advantage for man: help control rodent and insect pests

7. Flight or No Flight
Not all birds can fly: penguins have wings but use them as fins to help swim. The ostrich wings are useless, but they have powerful legs that make them one of the fastest animals on earth.
Wings and hollow bones allow most birds to fly.
Flight requires much oxygen and energy!
For energy, birds can eat their body weight in food each day, sometimes storing it in the crop.
Air sacs allow the bird to have fresh air in their lungs when inhaling and exhaling. Plus the air sacs help cool the birds body temperature.

8. Nests and Eggs One characteristic of birds is that they lay eggs.
Egg = embryo, yolk (food supply), albumen or egg white (liquid environment), a shell membrane, and a brittle shell (allows gasses to exchange).
Birds build nests and incubate their eggs by sitting on their eggs. Eggs must be turned in order for normal development to occur.

9. Section 3 Mammals
Mammals are warm-blooded animals that have hair and produce milk.
On some mammals the hair is hardly noticeable like whales.
Others have so much we call it fur like dogs.
Milk is produced in the mammary glands of the mother mammal and it provides the fat, protein, carbohydrates, vitamins, and minerals, and water that an infant mammal needs.

10. Three Groups of Mammals
Monotremes: Mammals that lay eggs
Duck-billed platypus and spiny anteater are the only monotremes. They live in Australia, Tasmania, and New Guinea.
Marsupials: Mammals with a pouch (NOT born in pouch)
Kangaroos and opossums
Placentals: Theses animals get their start in a placenta connected to mom via an umbilical cord. (most mammals including humans)