Hibernating butterflies

The Brimstone is one of five species of British butterfly that spend the winter as adults rather than eggs, larvae or pupae. The others are the Small Tortoiseshell, Peacock, Comma and, recently, a few Red Admirals. These five species choose very different places to spend the winter. Peacocks and Small Tortoiseshells tend to prefer wood piles, and in recent years have also been found to overwinter in sheds, garages and outbuildings, and even inside homes; anywhere they can stay suitably cool. Commas prefer to hide in dead leaves. Red Admirals usually migrate here in spring, then die off in late autumn, but in recent years have begun to spend the winter in southern Britain, choosing ivy and other evergreen shrubs. All these large and hardy butterflies also take advantage of warm, sunny days early in the year to emerge and feed on nectar. However, if there is a sudden cold snap, they will usually return to their winter hiding place until spring properly arrives. In recent years, our overwintering butterflies have enjoyed very different fortunes. Having almost become extinct in Britain in the late 19th century, the Comma has made a major comeback and has spread northwards to colonise Scotland. Likewise, the Peacock has also surged north and can even be found in Orkney and Shetland. However, the Small Tortoiseshell has unfortunately fallen victim to a parasitic fly, which kills the caterpillars before they can pupate.