A conservation group has announced the sighting of a previously thought-to-be-extinct butterfly in the southern region of England. The Large Tortoiseshell Butterfly has been spotted in various locations including Kent, Sussex, The Isle of Wight, Cornwall, and Dorset, leading Butterfly Conservation to reclassify the species as now breeding in the UK, rather than being migratory. This reclassification marks the first time since the 1980s that the butterfly has been identified in this manner.
Professor Richard Fox, head of science at Butterfly Conservation, mentioned to the BBC that the reasons behind the disappearance and reappearance of the butterfly in Britain remain unclear. However, it is believed that climate change may be a contributing factor pushing increased numbers of the species across its European habitat.
Distinguishing features of the Large Tortoiseshell Butterfly include its larger size compared to the small tortoiseshell butterfly, as well as the absence of white dots on its wing tips, which the smaller species possesses. Caterpillars of the Large Tortoiseshell feed on leaves from elms, willow, aspen, and poplar trees.
Historically, the spread of Dutch elm disease was thought to have played a role in the decline of the Large Tortoiseshell Butterfly. Yet, current research suggests that the species was naturally at the upper limit of its range, with global warming now aiding its return to the UK.
The phenomenon of species making comebacks due to rising temperatures is not unique to this butterfly. Warmer conditions have also been linked to continental moth species either migrating to or reestablishing themselves in the UK. Butterfly Conservation encourages the public to report sightings of the Large Tortoiseshell Butterfly on the iRecord app to help track their reproductive locations and patterns.