Question

What are the features of class aves which help them in flying?

Answer 1

The big stiff feather is available on the wings and tails of the birds. This is called the flight feathers. This feature will produce the push for the fly movement in the birds. Flightless birds did not have flight feathers on their wings. They have floppy and limp on their feathers. So feathers in the tail and wings are used for fly movement of birds. Pennae volatus are called the flight feathers. It looks long, and has an asymmetrical shape but having a symmetrical arrangement.

Complete answer:
Anterior limbs are transformed into the wings and it is attached to the well structured musculature. Birds have lightweight bones which are filled by the air. These bones are called the pneumatic bone. This feature reduces the body density to make them fly. They can't get any colon or bladder to store the urine. They excrete the uric acid. So they need less water and less storage space. Birds have aerodynamic bodies and lungs. They also have specialized air sacs.
Birds have well developed muscle structure for good flight. Endoskeleton is the bony structure which has the internal holes filled by the air cavities. They have a spindle shaped body. So it acts as the resistance to the wind. Feathers are used to prevent the heat loss and it will reduce the air friction. It provides the passage to the air on the bird’s body. They also have light weight and smooth feathers. It will reduce the drag by the air. Enlarged breast bone is called the sternum which is attached to the flight muscle. So it helps in the force of thrust. Air sac is used to get much more oxygen from every breath compared to other animals.

Note:
Flight feathers are designed like the thermoregulation and streamlined position during the flying. Birds change their direction by the tail. This is called the molting patterns. Flight feathers molting varies widely from bird to bird. Feathers are classified as three types. They are flight feathers, bristle feathers and down feathers. Feathers placed like a symmetrical manner in the wings. So after falling the feather will also be regrowing.