Butterfly Conservation warns of population crash despite record summer counts

The 2026 Big Butterfly Count revealed that record-breaking heatwaves in Britain resulted in the second-best butterfly season in 16 years. Over 100,000 volunteers recorded nearly 1.4 million butterflies and day-flying moths. Notable increases included painted ladies, which saw a 335% rise compared to the previous year, while holly blue and gatekeeper species achieved their highest counts since the study began in 2010.

Despite the high numbers of adult butterflies, Butterfly Conservation has issued a warning regarding a potential population crash in the coming years. Experts note that while adult butterflies thrive in hot, sunny weather, the extreme drought conditions may have devastated caterpillar populations. Many essential plants and wildflowers withered before caterpillars could finish feeding, which could lead to a significant decline in numbers by 2027. Richard Fox, head of science at Butterfly Conservation, noted that similar extreme droughts in 1976 and 1995 led to severe impacts on species that some have never fully recovered from.