The peat is dry and soft underfoot, a springy sponge topped with a green scouring pad of heather and gorse. A narrow path weaves through the abrasive stems, from the remote Warren House Inn (with its famous fire, said to have been burning continuously since 1845) down into a valley littered with the ruins of mine buildings. Vegetation has healed the scars of centuries of industry, but its evidence is everywhere – from overgrown spoil heaps and wheel pits to gullies carved into the hillside.
This is the start of my favourite walk on central Dartmoor – a circuit of about five miles which passes through medieval farmsteads and alongside the walled bronze age settlement of Grimspound.
But it is the first few hundred metres that I relish most – the deep-cut track submerging into a sea of heather as it descends the slope.
As I pause in the sheltered channel, inhaling the coconut scent of gorse, I notice something resembling a peach stone on the turf. Closer inspection reveals it to be the empty cocoon of one of our most magnificent insects: the emperor moth.
Active in spring, these hefty moths are strikingly patterned, their colourful wings bearing prominent dark eye spots front and rear, as if created with a hole punch. Males will fly by day in search of the larger and more secretive females. The warm conditions are ideal, and I keep a lookout for them as I walk.
It is only when I return to this section of path, on the way back to my car, that I finally spot one racing low over the heather. It could easily be mistaken for a butterfly, being roughly the same size as a small tortoiseshell. But there is something less refined and more urgent about its fluttery flight.
Such haste is understandable. The male – chocolate and orange markings just visible as he hurries past – does not feed. Instead, he dedicates his short life (of less than a month) to finding a mate, tracking the pheromones of females over long distances. Another male follows close behind. Then a third playing catch-up.
This moorland expanse, so inviting for a leisurely stroll in the sunshine, is no place to relax and unwind for these manic moths.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024 is published by Guardian Faber; order at guardianbookshop.com and get a 15% discount
