This part really shows Biggers emotions of trapped. He sees the pigeon flying and sees himslef as less of an animal. He cant go where he wants and camt do anything he wants, but the pigeon can. Bigger just wishes to have more freedom.
This section begins the flight section. Bigger feels relieved after killing Mary. All his anger was transfered and he felt justified for his crime
This section explains the fall section. Now Bigger is more agressive and the guilt and pressure of his actions is flooding in and now its hard to handle nd he is lashing out