I'm pretty sure wings and an air sac in the abdomen, which is constantly filled with air through a breathing process that is unique to those animals who have it.
wings are helpful.
Not sure what you mean by that, but birds do fly.
It is not only birds that fly. Bats fly and they are not birds.
There is a distinct difference. I believe I can fly, and birds just fly. :) Just kidding. People fly with 200 ton contraptions of metal and fire, while birds fly with 2 limbs of feather, skin, bone, and muscle. See the difference?
protection and warmth at night, and the ability to fly
firs because they have hallow bones that allows them to fly and so they can get away from things that will try to eat them
Most birds can fly. Not all.
To say that birds use wings and feathers to fly, so all birds can fly, would be false. Not all birds can fly. An ostrich is an example of a bird that cannot fly.
Migration of the birds occurs during autumn. The birds fly south prior to winter.
they all are flying things time flys and birds fly
The birds that can fly because it is easier for them to find food.
1. Hollow bones 2. Airtight feathers 3. No teeth 4.Egg laying 5. Fused collarbone