A windhover is a kestrel, a smallish bird of prey. They hunt by hovering, or perching, and then swooping down on animals - mainly mice - on the ground.
To be prosaic, just for a moment, windhovers can see light near to the ultra-violet range, and this enables them to see the urine trials of animals.
To Gerard Manley Hopkins, writing at Theological College in 1877, however, the windhover was not prosaic at all, in any sense. It was a creature of glorious poetry:
photo by Charles H Sharp Sharp Photography, sharpphotography
To Christ Our Lord
I caught this morning's minion, king-
dom of the daylight's dauphin, dapple-dawn-drawn Falcon, in his riding
Of the rolling underneath him of the steady air, and striding
High there, how he rung upon the rein of a wimpling wing
In his ecstasy! then off, off, forth on swing
As a skate's heel sweeps smooth on a bow-bend: the hurl and gliding
Rebuffed the big wind. My heart in hiding
Stirred for a bird, - the achieve of, the mastery of the thing.
Brute beauty and valour and act, oh, air, pride, plume, here
Buckle! AND the fire that breaks from thee then, a billion
Times told lovelier. more dangerous, O my chevalier!
No wonder of it: shéer plód makes plough down sillion
Shine, and blue-bleak embers, ah my dear,
Fall, gall themselves, and gash gold-vermillion.
Is that what you think to yourself when you see a bird?
Well, there's the point of poetry for you.
Word To Use Today: sillion. This word comes from the French sillon, furrow, and means the thick shining soil turned over by a plough.