This year’s Big Butterfly Count saw the lowest number of sightings recorded in the 13 years since the project began.
Wildlife charity Butterfly Conservation said it expected this year’s warm summer to result in better figures, and is concerned that more were not seen.
Almost 100,000 butterfly counts were submitted as part of one of the UK’s biggest citizen-science projects.
Dr Richard Fox, the head of science at the organisation, has called for more to be done to protect and restore butterfly habitats.
“The sun could shine for days on end, but we still won’t see more butterflies unless there is habitat for them to thrive in,” he said.