The world's largest insect survey, the Big Butterfly Count, returns from 18 July to 10 August, with organisers urging volunteers to spend 15 minutes in a local green space counting butterflies and day-flying moths. This year's count comes after a dramatic decline in 2024, which saw the lowest numbers in the survey's history and prompted Butterfly Conservation to declare a 'butterfly emergency'.
Naturalists report an 'outstanding' summer for many butterfly species, thanks to fine, sunny weather in April and May that boosted caterpillar survival. Early emergences of peacocks, gatekeepers, and marbled whites have been noted, alongside butterflies appearing further north than ever before—such as the purple emperor in North Yorkshire and the white-letter hairstreak in Dundee—likely driven by global heating.
Despite the encouraging signs, experts caution against 'shifting baseline syndrome'. Dr Richard Fox of Butterfly Conservation warns that a single good summer does not reverse 50 years of decline, and drought conditions pose a threat to future generations. While the sunniest spring on record and continued sunny weather have helped many species, some, like the rare large blue and common ringlet, have struggled due to dry conditions.
Matthew Oates, a naturalist and butterfly expert, described the turnaround as remarkable after last year's 'insect nadir', which he called the worst in nearly 70 years. However, he noted that not all species are thriving, with the small tortoiseshell continuing its baffling decline in southern Britain.
The Big Butterfly Count relies on up to 100,000 citizen scientists each year to provide valuable data beyond monitored nature reserves. Participants can log their sightings via the Butterfly Conservation website or free app. Dr Fox emphasised the mental wellbeing benefits of spending 15 minutes in nature, offering a sense of agency amid environmental threats.
