Among all animals, only birds have feathers. These feathers help keep them warm, protect them from harsh weather, and, in most cases, assist with flight.
Like mammals, birds also have a spinal cord.
Birds’ body temperature ranges from 40 to 44 degrees Celsius, which is higher than that of other mammals.
Birds’ beaks are made of lightweight bone covered with keratin, and their paws and feathers are also composed of keratin.
Birds have rotator cuffs that allow them to twist their necks.
Their ears and knees are covered by feathers.
The bones of birds are honeycomb-shaped, making them extremely light. These bones account for only five percent of a bird’s total body weight. Thirty to sixty percent of a bird’s total weight consists of muscle. Small birds have at least 15 bones in their necks.
The two vocal cords of birds join together to form a V-shaped bone known as the wishbone.
