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Hawk Roosting
by Ted Hughes

I sit in the top of the wood, my eyes closed.
Inaction, no falsifying dream
Between my hooked head and hooked feet:
Or in sleep rehearse perfect kills and eat.

The convenience of the high trees!
The air’s buoyancy and the sun’s ray
Are of advantage to me;
And the earth’s face upward for my inspection.

My feet are locked upon the rough bark.
It took the whole of Creation
To produce my foot, my each feather:
Now I hold Creation in my foot

Or fly up, and revolve it all slowly –
I kill where I please because it is all mine.
There is no sophistry in my body:
My manners are tearing off heads –

The allotment of death.
For the one path of my flight is direct
Through the bones of the living.
No arguments assert my right:

The sun is behind me.
Nothing has changed since I began.
My eye has permitted no change.
I am going to keep things like this.

The term “hawk-eyed” accurately describes many birds. For example, both raptors that must see prey at great distances and seed eaters that must pick tiny objects off the ground have eyes designed for high “visual acuity” — the capacity to make fine discriminations. There is, in fact, evidence that hawks can distinguish their prey at something like two or three times the distance that a human being can detect the same creature. Interestingly, even with such visual acuity, Cooper’s Hawks are known to hunt quail by their calls.

One way that birds have attained such a high degree of acuity is by having relatively large eyes. A human eye weighs less than I percent of the weight of the head, whereas a starling’s eye accounts for some 15 percent of its head weight. But more than size alone appears to account for the astonishing performance of the eyes of hawks. Evolution has arranged the structure of their eyes so that each eye functions very much like a telescope. The eye has a somewhat flattened lens placed rather far from the retina, giving it a long “focal length,” which produces a large image. A large pupil and highly curved cornea admit plenty of light to keep the image on the retina bright.

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