UK butterfly populations face possible crash after record-dry summer

Butterfly Conservation cautions that the unusually hot and dry summer may lead to a significant drop in butterfly populations when one outlet generation of caterpillars emerge as adults next year. While the warm weather boosted adult activity and produced a strong showing in the Big Butterfly Count, the same conditions deprived larvae of moisture and food plants, especially for species that are drought-sensitive. The count recorded nearly 1.4 million sightings, with record numbers for Holly Blue and Gatekeeper, but below-average figures for Speckled Wood, Green-veined White and Ringlet, each showing steep declines since 2011.

Historical droughts in 1976 and 1995 caused lasting damage to butterfly numbers, and today 80% of UK species are already in decline. Researchers warn that increasing frequency of hot, dry summers could push vulnerable species toward extinction.