WHEN the black velvet curtain drops, the farmyard, the meadow, the hill, the river remain the same theatrical stage. But the cast changes at night. Where swallows lacily wheeled around the cowfield in the sunshine comes the nightjar, hawking by hard angles in moonlight. Where butterflies fluttered in the afternoon garden, at midnight the pale ghosts of moths flicker on the honey-suckled arbour. In place of bees on the lane’s verge, glow-worms. Instead of the thrush chanting in the orchard, the nightingale serenading. At night, the desolate fen is no longer the hunting ground of the marsh harrier, but of the short-eared owl.
Almost 70% of the world’s animals are nocturnal—for good reasons. Animals that feed by night exploit sources of food that are also taken by day animals, but without coming into direct competition with them. Also, daylight desiccates and
