Why do birds live longer than mammals of the same size?

1, different kinds of birds have different life spans. The longest can generally reach 70 years, or even hundreds of years, such as parrots. Some only live for 2-3 years, such as sparrows. Generally, the life span of small birds is relatively short, while that of large birds is relatively long.

2. Birds, also known as birds. Definition: Egg-laying vertebrates covered with feathers. The main characteristics of birds are: streamlined bodies (spindle or spindle), most of which can fly. The body surface is covered with feathers, and the forelimbs generally become wings (some kinds of wings degenerate); The pectoral muscles are developed; Short rectum, large appetite and fast digestion, that is, the digestive system is developed, which helps to lose weight; The heart has two atria and two ventricles, and its heartbeat is fast. The body temperature is constant. In addition to the lungs, the respiratory organs also have multiple airbags to assist breathing, so that birds can have oxygen passing through the lungs when inhaling and exhaling, that is, double breathing.

3. Introduction: Birds are higher vertebrates that adapt to life on land and in the air. Long feathers can keep the body warm; There are protruding keel processes on the chest, and there are many gaps in the whole body bones, which are full of qi, so they are light; The forelegs become wings, and the hind legs walk. Most of them can fly and have a wide range of activities. Some of them can't fly because of the degradation of their wings, and their activity areas are relatively small, such as ostriches, penguins and most poultry. Horny beak, toothless, some birds have migration behavior. Greatly improved the survival rate of chicks. Birds can build nests, hatch eggs, brood and migrate. There are many kinds and quantities with traces all over the world. Some birds live and breed in their breeding areas all the year round and do not migrate because of seasonal changes, which is called "resident birds"; Some birds migrate from south to north every spring and from north to south in late autumn. This kind of bird is called "migratory bird". Birds are closely related to humans. Poultry can provide meat and eggs; Some beneficial birds can kill pests and rodents and protect crops and trees, such as swallows and owls. Some birds are available for viewing. In order to protect the ecological environment, we should take good care of beneficial birds and prohibit killing.