Write some of the special features of feathers

Feathers perform a number of functions for a bird:

1) They provide insulation, body temperature of most birds is maintained at around 40 C.

2) Feathers allow for flight.

3) Feathers control what a bird looks like by supplying the bird with colors.

Explanation:

Feathers insulate birds from water and cold temperatures. They may also be plucked to line the nest and provide insulation to the eggs and young. The individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads.

for a different answer set the answer would be because the oxygen in the water had depleted (apex)