In "The Windhover," a man goes totally nuts over a bird in flight. Why is it that he's so into birds? Is he really an ornithologist? We're guessing that he's not, since he calls the windhover "daylight's dauphin" and "dapple-dawn-drawn Falcon" (2), instead of Falco tinnunculus. There's something about seeing this bird in its natural element, hovering on the wind, that the speaker of "The Windhover" finds absolutely awe-inspiring.
The many metaphors and similes of "The Windhover" all relate to the harnessing of natural power: the windhover itself harnesses the wind, the horseback rider controls the strength of the horse, the skater glides with control over the ice, and the plough cuts into the earth to plant seeds.
Harnessing natural power, as the windhover does, is both beautiful and potentially hazardous, which is why the speaker hints at the "danger" of the windhover's flight in 11.