1. Chapter Birds
Birds are reptile-like animals that maintain a constant internal body temperature.

2. Pictures of Birds

3. Characteristics of Birds
Class Aves
Feathers, wings and thin hollow bones which allow for flight
Keel shaped sternum
4 chambered heart
Respiratory systems consist of: lungs, anterior and posterior air sacs
Endotherms (warm blooded)
Able to regulate their internal body temperature

4. Characteristics of Birds
Internal fertilization (sexual)
Amniotic eggs w/ hard shell
Incubate their eggs (keep at a consistent temperature)
Adaptations of birds
Feathered legs and feet of ptarmigans
Modified wings and feet of penguins
Large eyes, acute sense of hearing and sharp claws of owls
Long beaks of hummingbirds

5. What is a Bird? Class Aves
Feathers, modified scales that provide insulation & flight
Wings, power provided by muscles attached to sternum (breastbone)

6. Feathers are made mostly of protein and develop from pits in the birds' skin.
Feathers help birds fly and also keep them warm.
The two main types of feathers are contour and down.

7. Feathers
Feathers

8. What is a Bird?
Other adaptations for flight include hollow bones, high metabolism maintained by 4 chambered heart & air sacs
Endotherm, maintains a nearly constant body temperature that does not depend on environment

9. Skeletal System of a Bird

10. Bones are strengthened by struts.
Air spaces make bones lightweight.

11. Form, Function, and Flight

12. Body Temperature Control
Birds are endotherms (animals that can generate their own body heat)
They have a high rate of metabolism compared to ectotherms (metabolism produces heat)
A bird’s feathers insulate its body enough to conserve most of its metabolic energy

13. Bird Feeding
The more food a bird eats, the more heat energy its metabolism can generate
For this reason, the phrase “eats like a bird” is quite misleading – birds are voracious eaters
A bird’s beak, or bill, is adapted to the type of food they eat

14. Bird Digestion

15. Bird Respiration
When a bird inhales, most air first enters large posterior air sacs in the body cavity and bones
The inhaled air then flows through the lungs in a series of small tubes
A complex system of air sacs and breathing tubes ensures that air flows into the air sacs and out through the lungs in a single direction
This constant, one way flow of oxygen-rich air helps birds maintain their high metabolic rate and generates enough energy for flight

16. Bird Circulation Circulation
4 chambered hearts and two separate circulatory loops

17. Structure of Bird’s Heart
Domestic pigeon
Right atrium
Left atrium
Right ventricle
Left ventricle
Heart
Complete division

18. Bird Excretion Excretion
Similar to those of reptiles – white, pasty uric acid droppings

19. Bird Response Response Well developed sense organs
Well developed eyes that can see color
Excellent hearing

20. Reproduction in Birds Bird eggs are amniotic eggs
They have hard outer shells
Most birds incubate their eggs until they hatch

21. Diversity of Birds
A bird’s lifestyle is determined by its type of beak and feet.

22. Diversity of Birds

23. Diversity of Birds