Birds and the Origin of Flight

1. Birds and the Origin of Flight

2. Major Features • The Aves or birds contains about 9,000 species, ranking it second only to the bony fish in number of species • Feathers • Associated with flight - the major characteristic feature of birds is the capacity for flight. • modified scales

4. Feathers as Insulation • The evolution of feathers may have been important in providing insulation that would help maintain a body temperature higher than that of the surrounding environment.

5. Feathers and Flight • Being airborne, birds have more mobility and access to resources. • Not all birds are capable of flight, but flightless birds are evolutionarily derived from flying ancestors.

6. Adaptations for Flight • Things that fly must be made to fit strict specifications. • This is why most birds have a similar body shape, even though they live in very different habitats and have very different diets.

7. Adaptations for Flight • Reduction in the weight • hollow construction of the skeleton

8. Adaptations for Flight • Fusion and loss of bones and teeth

10. Adaptations for Flight • Fused clavicles and keeled sternum

11. Adaptations for flight • 4-chambered heart

12. Adaptations for flight - respiration

13. Adaptations for Flight • Reduced urogenital system

14. Flight – the basics • Lift (airfoil)

15. Flight – the basics

16. Birds are theropod dinosaurs