Kestrels have been my favorite raptor ever since I was introduced to one at the Montana Raptor Conservation Center years ago. They are summer visitors in Montana, seen perched on the fence posts or hovering in the air above a field. They are the only raptor that can hover, which gives them a great vantage point for the grasshoppers and other small critters they eat. They are easy to tell from the other raptors because they are about the size of a large, rapacious robin; the females are nearly the color of a robin, while the males have blue-grey wings. You can tell them from the robins because they sit upright like a raptor, not slanting like a song bird. Kestrels are one raptor that has profited from human development, since they do better in open grasslands than in forests.
Throughout the ages, kestrels have accumulated other names: sparrow hawk is a common one, although they eat many things other than sparrows. Windhover is an older name that shows up in one of my favorite poems by Gerard Manley Hopkins, The Windhover:
I CAUGHT this morning morning’s minion, king-
dom of daylight’s dauphin, dapple-dawn-drawn Falcon, in his riding
Of the rolling level underneath him 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.