Butterfly study finds sharpest fall on record for small tortoiseshell in England

Although numbers of the small tortoiseshell fell in England, Wales and Scotland, it had its second-best year on record in Northern Ireland. Photograph: Geoffrey Swaine/Rex/Shutterstock

The small tortoiseshell butterfly has suffered its worst year on record in England, and has declined by 82% across the UK since 1976, according to the annual scientific count of butterfly populations.

The sharp decline in numbers of the once-common garden butterfly has puzzled scientists, but it is thought to be linked to climate breakdown. It had its worst year on record in England, its second worst in Wales and its joint-fifth worst in Scotland in 2023 but did well in Northern Ireland, logging its second-best year.