Large Tortoiseshell Butterfly Declared Resident Species in the UK
The large tortoiseshell butterfly is now a resident species in the UK after being declared extinct in the last century. This significant development marks the first time in Butterfly Conservation’s 58-year history that the species has been classified as resident rather than migratory.
Recent sightings of the large tortoiseshell have been reported in woodlands across Kent, Sussex, Hampshire, Dorset, Cornwall, and the Isle of Wight. The butterfly’s return has contributed to an increase in Britain’s native butterfly count, which now stands at 60.
Historically, the large tortoiseshell butterfly flourished in Britain during the 1940s but was considered extinct by the 1960s due to factors such as Dutch elm disease. The species is larger than the small tortoiseshell and is distinguished by the absence of the white markings found on its smaller counterpart.
Experts believe that the large tortoiseshell’s return is linked to population rises in the Netherlands and France, as well as climate change. Caterpillars of the species have been found feeding in the wild since 2020, confirming that the butterfly is breeding again in Britain.
The large tortoiseshell hibernates as an adult and emerges in spring to mate and lay eggs. Adult butterflies from this year’s offspring are expected to take flight during midsummer. Richard Fox from Butterfly Conservation stated, “The signs are really positive, which is lovely,” and added, “It is resident and therefore it is another species to add to Britain’s total, which is good news.”
Despite this encouraging news, details remain unconfirmed regarding whether the large tortoiseshell will be widespread across multiple landscapes in the UK. Fox noted, “We’re still in that zone of uncertainty at the moment, but there are exciting signs.”
Butterfly Conservation is actively encouraging the public to log sightings of the large tortoiseshell using the iRecord app, further contributing to the monitoring and conservation of this remarkable species.