1. BIRDS

2. EVOLUTION
Birds are believed to have evolved from small, fast-running carnivorous dinosaurs during the Jurassic period.
The oldest bird fossil, found about 150 million years ago, belongs to the Archaeopteryx lithographica.
About 40 million years ago, most of the modern orders of birds have originated.

4. FEATHERS
Down Feathers: They cover the body of nestling birds and provide an insulation coat for adults.
Contour Feathers: They give adults their streamlined shape, provide coloration, and additional insulation.
Flight Feathers: They are specialized contour feathers on the wings and tails.

6. provides stability during flight
SKELETON & MUSCLES
Rigid skeleton
Bones are thin, hollow,
and many are fused.
provides stability during flight

8. METABOLISM
They are endothermic, which is generating heat to warm the body internally.
The rapid breathing and digestion of large quantities of food support the high metabolic rate necessary to generate this heat.
They cannot go for long periods without eating.
They fluff out their feathers to help conserve body heat.

9. DIGESTIVE & EXCRETORY SYSTEMS
The digestive and excretory systems are adapted for the rapid processing of food and metabolic wastes.
Crop: is an enlargement of the esophagus that stores and moistens food.
Proventriculus: this is where acid and digestive enzymes begin breaking down the food.
Gizzard: the muscular portion of the stomach that kneads and crushes food.
Pathway: mouth, esophagus, crop, proventriculus, gizzard(stomach), small intestine, large intestine, out the cloaca.

10. RESPIRATORY SYSTEM
The unique architecture of the bird’s respiratory system provides a virtual one-way flow of air.
The highly efficient system of air flow allows birds to maintain the high metabolic rate necessary for flight.
It also enables birds to function at high altitudes, such as 23,000 feet, where other animals would suffer from the lower levels of oxygen.

14. THERE ARE 29
ORDERS OF BIRDS

15. Anseriformes- Swans, Ducks, Geese-160 species
Strigiformes- Owl-180 species
Apodiformes- Hummingbirds & Swifts-420 species

16. Psittaciformes- Parakeets, Budgerigars, Cockatoos-360 species
Piciformes- Woodpeckers, Honeyguides,
Toucans-350 species
Falconiformes- Hawks, Falcons,
Eagles-310 species

17. Passeriformes- Robins, Blue Jays, Wrens-5,700 species
Columbiformes-Pigeons, Doves-310 species

18. Ciconiiformes-Herons, Storks, Egrets-120 species
Galliformes-Turkeys,
Pheasants, Chickens, Grouse-260 species

19. Sphenisciformes-Penguins-17 species
Struthioniformes-Ostrich

20. DONE