Garden owners are being encouraged not to mow their lawns until September, due to more than half of UK butterfly species experiencing a long-term decline.
Experts have put this decrease down to habitat destruction by humans, pesticide use, and climate change.
The UK Butterfly Monitoring Scheme, managed by a number of conservation organisations, said that 2024 was one of the most disastrous years for butterflies in the UK. Species such as the small tortoiseshell, chalk hill blue, and small copper endured their worst year on record.
Richard Fox, from Butterfly Conservation, expressed his devastation at the decline in British butterflies, attributing it to human activities. 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 Fox mentioned that the wildlife charity was overwhelmed with inquiries last summer from people wondering where the butterflies had gone and how they could help.
He said: “By far the best thing we can do to help butterflies is to create more habitat”, referencing a study by the charity which found that allowing parts of gardens to grow wild with long grass boosts butterfly populations – especially in areas with gardens and intensive farming.
Dr Fox added: “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.”