Birds can fly because they have aerodynamic wings. Their feathers are light and flexible. They can fly because they use their tail as a rudder.
Emus, ostriches, and kiwis are three birds that cannot fly.
There are many reasons that birds fly the way they do. One reason for why they fly in a V formation is because it reduces the air resistance on the birds in the back of the formation.
Three Million
Kiwi, Ostrich, Cassowary.
Penguins cannot fly, nor did the dodo, which is why it is extinct. Also the emu and the ostrich. Neither of those two birds can fly.
A bird being light weight helps them to be able to fly. The fact the birds bones are hollow, feathers are light, and wingspan is only feathers helps them be able to soar the skies.
Penguin kiwi ostrich
NO
Because they can not walk & run
It is not only birds that fly. Bats fly and they are not birds.
Pengins , Dotle bird ,and chicken
Most birds are small for a variety of reasons. One reason is so they can fly faster. Another is so that predators have a harder time catching them.