Yesterday, I watched the animal world on TV. This is the program I watched since I was a child. Elephants were introduced into the film. After watching the program, I was very interested for a while, so I looked up some information related to elephants, which was a lesson for myself. Share some here.

Among mammals on land, elephants should be the longest-lived mammals, generally living 60 to 70 years old. Of course, the length of a person's birthday has a lot to do with the growing environment. Elephants in captivity often live longer than those in the wild. The artificially raised elephants have no worries about food and clothing all day, and will not be attacked by other species under the protection of human beings, so their life span will be relatively longer. In order to survive, wild elephants need to constantly forage, migrate, breed and avoid killing. Elephants will be injured or even killed at any time, so their life span will be shorter.

The life span of mammals is also related to their size. The bigger you are, the longer you live. The heart rate of larger mammals is slower, while the heart rate of smaller mammals is faster. The heart rate mentioned here refers to the number of heart beats per minute of animals, so the life span of mammals has a certain relationship with their heart rate.

Here's a question. Why is the body size related to the heart rate?

In nature, mammals are warm-blooded animals. Constant temperature here means that the body temperature will not be affected by the external temperature, and it has stronger adaptability to the changes of the external climate and environment. They can adjust their temperature to keep a constant body temperature. For example, the fur of ferrets can keep warm, and the sweat glands of cattle and horses can dissipate heat. When a mammal's body temperature is higher than its surroundings, its body heat will be emitted.

The bigger the animal's body, the higher the efficiency of maintaining body temperature and the slower the heart rate. On the contrary, the smaller the volume, the lower the efficiency of maintaining body temperature, the faster the heart rate, the faster the metabolism, the faster the decline and the shorter the life span.

To sum up, the elephant is the largest mammal on land at present, so its life span is relatively longer. Elephants are also national first-class protected animals and should be well protected.