Country diary: fretting at the bird ledges devoid of guillemots

Castlemartin, Pembroke: I thought about the brutal annihilation of its larger cousin the great auk. But I was worrying needlessly

Ten feet below the top of Mowing Word is a hollowed-out bedding-plane that stretches the whole length of this magnificent limestone cliff. Decades of nesting auks have whitewashed the rock, making their breeding site obvious even from a distance. Though it's one of the best locations for sea-cliff ascents in Britain, voluntary bans negotiated years ago between naturalists and climbers have generally been scrupulously observed during the razorbill and guillemot breeding seasons. The critical period is during incubation, which generally takes place in June, is short, and concludes with the fledgling guillemot, accompanied by its father, flailing off the ledge to bounce and belly-flop its way to the water below.