I often think about this poem by William Stafford called "Travelling through the Dark"

Traveling through the dark I found a deer
dead on the edge of the Wilson River road.
It is usually best to roll them into the canyon:
that road is narrow; to swerve might make more dead.

By glow of the tail-light I stumbled back of the car   
and stood by the heap, a doe, a recent killing;   
she had stiffened already, almost cold.
I dragged her off; she was large in the belly.

My fingers touching her side brought me the reason—
her side was warm; her fawn lay there waiting,   
alive, still, never to be born.
Beside that mountain road I hesitated.

The car aimed ahead its lowered parking lights;   
under the hood purred the steady engine.
I stood in the glare of the warm exhaust turning red;   
around our group I could hear the wilderness listen.

I thought hard for us all—my only swerving—,   
then pushed her over the edge into the river.