Adense, early morning fog blanketed the moorland valley. From my garden I could just make out submerged shapes of scattered stone buildings, soft silhouettes of trees skirting the hillside, the pale disc of the rising sun like a pill dissolving in the mist. I stood and waited, listening hard for the sound that had brought me outside. Then it came again, cutting through the damp air, two notes repeated with the rhythm of a heartbeat: Cuck-oo. Cuck-oo. Cuck-oo. It must have arrived in the night. Now at dawn it proclaimed its arrival on Dartmoor with such stridency it all but silenced the chorus of smaller birds. I hoped that other early risers in the village were listening in – it felt too important to miss. Its clear and simple song sounded as if it might carry for miles. I liked to imagine it drifting far and wide across the county, the country, that I might share such a precious sign of spring. If I could, I would have shaken the population awake and urged everyone to cock an ear in this direction: “Listen – can you hear it? Can you hear it?” We are fortunate to get cuckoos every year along this western fringe of Dartmoor, but as numbers dwindle nationally it is a relief when they return. Fewer and fewer people will get to welcome back this annual visitor. And that is particularly sad for such an eccentric spring celebrity, with its comical clock connections and dump-and-run attitude to parenting. The cuckoo is also one of a handful of bird species that even non-experts can recognise by song alone – a connection with nature that is gradually being lost. I got into my car and drove the short distance to the moor. Windows wound down, stopping every so often, I followed its voice in the mist. There was little sense in getting out and trying to close the gap on foot, given the lack of visibility. It hardly mattered. It is the sound, rather than sight, of a cuckoo which is so distinctive. I sat in a layby with the engine off, savouring the notes until the bird moved on unseen. Gradually its call grew fainter – a fading pulse in the fog.