Country diary: butterflies instinctively make chemistry sexy

Wyre Forest, Worcestershire: The male pearl-bordered fritillaries were laying pheromone trails low along the track

The amber flicker materialised in air so saturated that it steamed through the trees, sauna hot. The orange light became two, spinning around each other only a metre above the ride, knotting and unknotting in the air. These were small pearl-bordered fritillary butterflies, Boloria selene, males in a dogfight over territory.

After each skirmish they separated, flying low in opposite directions, occasionally stopping to feed on bugle flowers or resting for a brief moment. Only then was it possible to see the black patterns on their orange wings, like glimpsing a sunset through the leaded lights of stained glass. The undersides of the wings, when they flexed at rest, revealed pearly, futurist compositions of bright, reflective panels.