All it has to do is wander around the woods putting its offspring callously into care – then clear off back to Africa.
The books tend to dismiss the cuckoo as a parasite. As indeed it is.
But finding the right foster parents can be a battle, and requires weeks of patient work.
It also requires patience from the ornithologist to find out what really happens.
I have tried this in the past in these woods when cuckoos were common here 20 years ago with three males fighting it out for prime territory in the coppice.
I was lucky once, when I watched a female glide down into the hazels only 20 yards from me.
After a minute or two she rose up with that extraordinary bubbling call of triumph and relief – like a demented witch.
A grey egg like igneous marble lay with the three turquoise gems of the dunnock in their cup of velvet moss.
That would seem to have been an easy birth.
Mother dunnock had fussed around but had given the huge invader very little real grief.
But back in 1922 one ornithologist, Edgar Chance, had quite a different tale to tell. He and his chum Smyth set up camp with Charlie Chaplin-style winding film camera in prime cuckoo habitat on a heathery common.
Every movement of the birds was recorded. And in due course it was all published in The Cuckoo’s Secret by Sidgewick and Jackson. One day Chance had been sitting in his hide as usual for several hours when a female cuckoo came into view.
It glided down and landed in front of him.
It started to potter about looking for the nest of the meadow pipit which she knew was somewhere there on the ground – the parents having given themselves away by their own, although discreet, behaviour.
Three pipits attacked this cuckoo, diving and pulling feathers out of the back of her neck.
She grunted defiance at them but they did not give up. After a quite fruitless hunt she gave up and flew back to her reconnaissance tree.
After a while she again glided in, hunting backwards and forwards for the nest. Again she was attacked and beakfuls of her feathers were ripped out.
This went on for several minutes. Then suddenly she spotted the nest and made a dive for it.
For eight to ten seconds she sat perfectly still, looking for all the world like a placid pigeon: then she flew hurriedly away from the indignant owners, leaving her egg in their care, eating one of theirs in exchange.
Now if these attacks are something she has to endure for every one of her 14 eggs, she is running quite a gauntlet from the chosen surrogates.
On June 15 she then has to face those thousands of miles across the savage Sahara.
I think she’s a brave bird: I only hope she comes back to us again.
I forgive her sins for the chance to hear that almost mystical sound: cuckoo, cuckoo.