Narcissism
The title character believes that the entire process of evolution has led to his existence. The poem is one long sustained psychological expression of misplaced self-importance. The hawk is the equivalent of a politician creating his own reality of the world around him and situating himself at the center of that world. The hawk becomes the personification of an overinflated ego viewing itself as the ultimate aim of the entire design of the universe.
Resistance to Change
The final stanza of the poem has the hawk believing that nothing has changed since he came into being. The last two lines of the poem have the hawk insisting that he is in control of all he sees and therefore nothing will ever change. This is a delusional state of mind, obviously, but it is beyond question the bird believes it. The hawk is expressing a dangerous but pervasive mindset that rejects change. The problem is that the world is changing all around him. The only difference is that he does not realize it. The theme being pursued here is that this mindset which rejects critical thinking creates a very dangerous situation for those who want only to maintain the status quo.
Hyper-Focus
The hawk is hyper-focused on his natural instincts as a killer. This has made him quite an efficient killing machine to the point he has no fear of becoming prey himself. Such is his focus on his instinct that he allows no room for "manners" or "arguments" or any sort of doubt. This intensity of focus makes him a perfect predator, but at the cost of any real joy in his own existence. He may think that evolution has been directed to creating him, but even if that is so it means the entire point of his existence is simply to kill. The poem explores the theme of a meaningless life if there is nothing but single-minded devotion to any one particular aspect of life.
