Butterfly Conservation Head of Recording Richard Fox said: “We don’t understand what is causing the drastic long-term decline of this familiar and much-loved butterfly. Theories involve climate change, pollution and parasitic flies that kill the butterfly’s caterpillars, but we need more information.

“If you see Small Tortoiseshells or any other butterflies in your garden, the Garden Butterfly Survey provides an easy way to enter your sightings, contribute to citizen science and store your records for posterity.” butterfly-conservation.org