Country diary: Waiting for a nightjar is elusive and maddening – then thrilling | Mark Cocker

Goyt Valley, Derbyshire: My patience into dusk is rewarded with a full display of unlikely calls and aerial prowess

The setting sun spread a last Iberian glow over the hills opposite before they were drained of colour and sound, and by nine, the world was in monochrome. In line with national increases in their numbers and range, nightjars have prospered here recently. It seems especially so with the clearance of conifers, which has left a mix of old Scots pine and open space perfectly suited to this crepuscular ground-nesting migrant.

You hear nightjars much more than see them. Churring is the name given to their vocalisation – a continuous unfurling throat song that is one-part stridulation, one-part deep earth rumble. It feels subterranean, but also flows weightlessly like mist. Intermittently the unseen bird will turn its head; the song shifts key, then resumes, but its location is barely more obvious.

Flying nightjars constantly make another noise – a monosyllabic “gwic” call – that is so sharp, so emphatic that it seems almost to shine. Perhaps imagine the sound as an iridescent beetle, and as the bird moves so the glittering call shifts through the plantation shadows. If a nightjar’s churr is soothing, this call is maddening as you fail to fix the author while he passes.

At last, you glimpse a silhouette and the thrill of nightjars finds full outlet. You’re struck most by the extraordinary length of its tail and body, but especially those slender wings, which yaw now almost in slow motion as it hangs or weaves through the trees. One detail comes to dominate, because a male’s outermost flight and tail feathers have intense white terminal spots and, while a flying bird merges with the background, those luminous dots inscribe zany lines of white into the darkness.

There is one further sound to mention. If a pair combines in a brief aerial tangle, as they did tonight, both sexes can bring their wings together high overhead. The night air vibrates with their impact and it comes to the ear as a loud, clear clap. It is at once elemental and an outcome of exquisite control, and as you walk back into the increasing white noise of our kind, you realise you have encountered something precious that is indisputably ancient and mysterious.

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