Overview
- More than 125,000 people recorded about 1.7 million butterflies and moths between 18 July and 10 August, averaging 10.3 per 15‑minute count.
- Overall numbers returned to modern averages despite the hottest summer on record, with higher per‑count figures seen in 2023 and in every year from 2016 to 2020.
- Large white led sightings with roughly 396,510, and along with small white and the day‑flying Jersey tiger moth posted best‑ever Big Butterfly Count results.
- Several formerly common species remained depressed, with the small tortoiseshell still about 60% down since 2011, holly blue at its second‑worst result, and meadow brown at its fourth‑worst.
- Butterfly Conservation said weather‑boosted gains do not alter 15‑year trends showing more than twice as many widespread species declining as increasing.