A modest but resilient British butterfly has bucked the trend of worried predictions about the species’ health, with scientists reporting it appears to have benefited rather than lost out from climate change.
Brown Argus (Aricia agestis) butterfly roosting on grass. Photograph: Bob Gibbons/Alamy
The Brown Argus, Aricia agestis, named after a 100-eyed giant in Greek mythology because of the multiple eye-like dots on its underwing, has long been dependent in the UK on a single plant species, the rockrose Helianthemum nummularium. It appears this is probably because the plant tends to grow on south-facing slopes and absorbs the warmth and sun which the butterfly’s caterpillars need.
But hundreds of records kept by amateur butterfly enthusiasts since 1990 show that Brown Arguses have expanded their range by 40 miles in the past two decades, moving north at more than 2.3 times the average pace of other flourishing insect species.