Agonistic Behavior
Within certain animal species, conflicts sometimes arise over resources such as territory or food. To resolve these conflicts, two animals of the same species may engage in agonistic behavior. With this type of aggressive behavior, the animals participate in a physical competition that demonstrates which animal is more powerful. While each animal attempts to prove its strength in the competition, it typically does so without harming the other animal. Once the winner is established, that animal gains access to the desired resources, while the weaker animal surrenders and leaves the area.
听力材料：
Now listen to part of a lecture in a biology class.
I know some scientists who were observing snakes in the wild. And they witnessed an encounter of this sort between two rattlesnakes.
Uh...as you may know, rattlesnakes eat various kinds of small animals. Small animals that live underground, in burrows, in little holes in the ground. And what these scientists saw was these two rattlesnakes had found the same hole and both wanted to eat whatever food was in that hole.
So what happened was: The two rattlesnakes faced each other and then they lifted their bodies into an upright position and made themselves as tall as possible. And then they started pushing each other, kind of wrestling with one another, each snake trying to gain control of the other snake.
And what's interesting is that during all these pushing and shoving and maneuvering, neither snake ever tried to bite the other snake. Neither snake ever tried to injure the other snake. So...after this went on for a while, one of the snakes finally gained control of the other snake, pushed it to the ground and held it there. At this point, the snake that was on top could have easily bitten the other snake. But it didn't. Instead, it just released the other snake, just let it go. The snake that had lost just slithered away, and the snake that had won went down into the hole to look for food.
Question：
Explain how the example in the lecture illustrates agonistic behavior.
