Birds and the Origin of Flight

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

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.

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.

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.

Adaptations for Flight

Reduction in the weighthollow construction of the skeleton

Adaptations for Flight

Fusion and loss of bones and teeth

Adaptations for Flight

Fused clavicles and keeled sternum

Adaptations for flight

4-chambered heart

Adaptations for flight - respiration

Adaptations for Flight

Reduced urogenital system

Flight – the basics

Lift (airfoil)

Flight – the basics

Birds are theropod dinosaurs