The Return of the Large Tortoiseshell Butterfly in the UK
The large tortoiseshell butterfly is now a resident species in the UK after being declared extinct in the last century. This marks a significant milestone in the conservation of Britain’s native butterflies, bringing the total count to 60.
Recent sightings of the large tortoiseshell have been reported in woodlands across several regions, including Kent, Sussex, Hampshire, Dorset, Cornwall, and the Isle of Wight. Richard Fox from Butterfly Conservation noted, “The signs are really positive, which is lovely,” emphasizing the importance of this development.
This is the first time in Butterfly Conservation’s 58-year history that the large tortoiseshell has been classified as resident rather than migratory. Historically, the butterfly thrived in Britain during the 1940s but was considered extinct by the 1960s due to factors such as Dutch elm disease.
The return of the large tortoiseshell is believed to be linked to population increases in the Netherlands and France, alongside climate change. Caterpillars have been found feeding in the wild since 2020, confirming that the butterfly is breeding again in Britain. The species is known for its distinct characteristics, being larger than the small tortoiseshell and lacking the white markings found on the smaller species.
Adult large tortoiseshell butterflies hibernate and emerge in spring to mate and lay eggs, with this year’s offspring expected to take flight during midsummer. Fox remarked, “It is resident and therefore it is another species to add to Britain’s total, which is good news.” This resurgence highlights the ongoing efforts and successes in butterfly conservation.
Butterfly Conservation is encouraging the public to log sightings of the large tortoiseshell using the iRecord app, fostering community involvement in monitoring this species. Observers are optimistic about the butterfly’s future, although details remain unconfirmed regarding whether the large tortoiseshell will be widespread across multiple landscapes in the UK.
As the large tortoiseshell butterfly continues to establish itself, the conservation community remains vigilant, monitoring its progress and the ecological factors that contribute to its survival. Richard Fox noted, “We’re still in that zone of uncertainty at the moment, but there are exciting signs,” reflecting the cautious optimism surrounding this remarkable comeback.