The speaker of this poem never comes right out and introduces himself, so we have to dig a bit to figure out what makes him tick. We know that he's a morning person—he's apparently the only other living thing outdoors to witness the awesomeness of the windhover's flight. He also has a deep appreciation for the beauty of nature.
Our nature-loving morning person also has quite a way with words. He manages to come up fresh and exciting ways of describing something that we've all seen dozens, if not hundreds, of times: a bird flying in the sky. Somehow, the way the speaker describes it, it's as though we're looking at this bird with fresh eyes, for the very first time.