Garden owners are being urged to avoid mowing their lawns until September, as more than half of the UK’s butterfly species are experiencing a long-term decline. Experts have put this decrease down to destruction by humans, pesticide use, and climate change.
The UK Butterfly Monitoring Scheme, managed by several conservation organisations, declared 2024 as one of the most catastrophic years for butterflies in the UK. Species such as the small tortoiseshell, chalk hill blue, and small copper suffered their worst year on record.
The monitoring data reveals that 2024 was the fifth worst year on record for butterflies, with 51 out of the UK’s 59 butterfly species experiencing a decline compared to 2023, while only six saw an increase.
It was the second worst year on record for common butterflies found in gardens, parks, and the wider countryside, including the common blue, gatekeeper, and large whites. Nine species experienced their worst year since records began.
Dr Richard Fox, from Butterfly Conservation, said that the wildlife charity was inundated with inquiries last summer from people wondering where the butterflies had gone and how they could help.
In a plea to those with gardens, he urged: “By far the best thing we can do to help butterflies is to create more habitat”, highlighting a study by the charity which found that wilder garden patches with long grass significantly boost butterfly numbers, particularly where gardens and intensive farming are prevalent.
He continued: “That is why we are calling on people and councils across the UK to pledge to not cut their grass this year from April to September. This simple act can make a real, immediate difference to butterflies, moths and other wildlife.”
Dr Marc Botham, a butterfly ecologist at the UKCEH, said: “These deeply concerning results from the UKBMS emphasise just how important it is to monitor and record our wildlife so we can target conservation efforts and protect our beloved species.
“Butterflies in particular are valuable not just in their own right but also as indicator species, meaning they can tell us about the health of the wider environment, which makes the UKBMS data invaluable in assessing the health of our countryside and natural world in general.”