There are only about 4 billion people on earth and most of them enjoy watching all those birds. The best time to see birds in action is in the morning when they are feeding and fluttering about. Not all birds are the same, but they do have some common features that help distinguish them from other animals. Some of these characteristics are described below. All birds have thousands and thousands of feathers, which keep them warm and dry.
Most birds go through a molting stage once a year when they lose all of their feathers.
During this stage, the birds never lose all of their feathers at one time so that they can continue to fly. Sometimes the feathers become separated which can prevent the bird from flying. To fix this, the bird preens , or zips them back together by combing them with its beak. They have oil glands which help waterproof the feathers. On the shaft are barbs , tiny hooks, which hold the feathers together.