There is no moon and the dark is so deep walking into the field feels like being swallowed. I walk uphill and listen to my feet sweep the wet grass while bullfrogs throb a syncopation from the pond.

This field is vast and while I know where I want to go, the dark is disorienting. Having lost the power of sight to the night I listen for the muted, murmured sounds of the sheep to draw me in; a flock never really stops talking to itself.

Thirty heartbeats later, I'm at the edge of their paddock. I breath out and speak to the ewes in a low voice before scissor-hopping over their electric fence, happy to have cleared it completely. It doesn't always happen that way and the result is, well, shocking.

Now I need light and I switch on my headlamp. The night is suddenly alive with hundreds of eyes, a sea of startled fireflies. Among them I'm looking for one ewe. She started her labor earlier and should be lambing now if all is well.

After a moment I spy a single pair of eyes, alone and adrift near the fence line. She turns her head away and the green-fire reflections blink out. I creep carefully close and I can see she is attending to something on the ground. She makes a low, chuckle-gurgle in the back of her throat, a sound ewes make only when they are talking to new lambs.

I wait and again count my heartbeats to pass the time, twenty, thirty...fifty. Then I hear the sound that cracks my shepherd heart every time, a bleating, pleading, ascending note that seems to be the birth song of all mammals. All is well and I retreat, happy to leave the ewe to the privacy of darkness and her time-old task.