Bird Feather

Feathers are unique in the animal kingdom

Bird Feathers

Feathers are unique in the animal kingdom.
All birds have them, but only birds have them.
Plenty of animals are covered in fur or scales, but birds and their feathers stand alone.
Even other animals capable of flight, such as bats, don't have feathers.
So why feathers and not fur or scales? Feathers are vital to birds for many reasons.
Primarily, though, birds use their feathers to aid in flight.
Feathers are made of a lightweight material called keratin, the same thing our hair and fingernails are made of,
according to the Royal Society for the Protection of Birds.
This material allows feathers to be lightweight, but also flexible yet rigid enough to withstand the rigors of flight.
Muscles are attached to the base of each feather, which allows the bird to move them as needed.
When in flight, as a bird flaps its wings down, the feathers move together.
Then, as the bird moves its wings up, the feathers move apart to allow air to pass through. The motion of the feathers aids in flight.
Source: Reconnect with Nature

Bird Feathers

Bird Feathers

Feathers are the ultimate characteristic of birds.
No other (living) animals have them.
The qualifier is required because feathers have now been found in fossil imprints of some dinosaurs and related reptiles.
Source: BirdWatching