Significant Comeback for the Large Tortoiseshell Butterfly
The large tortoiseshell butterfly is now a resident species in the UK after being declared extinct in the last century. This remarkable development marks a significant milestone in conservation efforts, particularly for Butterfly Conservation, which has classified the species as resident for the first time in its 58-year history.
Sighting Locations and Population Growth
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. With the return of this species, Britain’s native butterfly count has increased to 60, highlighting a positive trend in biodiversity.
Historical Context and Factors for Return
The large tortoiseshell butterfly last flourished in Britain during the 1940s but was considered extinct by the 1960s, primarily due to factors such as Dutch elm disease. The species is believed to have returned due to population rises in the Netherlands and France, alongside climate change, which may have created more favorable conditions for its survival and reproduction.
Breeding and Lifecycle
Caterpillars of the large tortoiseshell have been found feeding in the wild since 2020, confirming that the butterfly is breeding again in Britain. The caterpillars primarily feed on elm, willow, aspen, and poplar. The adult butterflies hibernate during the winter months and emerge in spring to mate and lay eggs, with the offspring expected to take flight during midsummer.
Public Involvement and Future Monitoring
Butterfly Conservation is actively encouraging the public to log sightings of the large tortoiseshell using the iRecord app, which will aid in monitoring the population and distribution of this species. Richard Fox from Butterfly Conservation stated, “The signs are really positive, which is lovely,” emphasizing the importance of public engagement in conservation efforts.
Ongoing Uncertainties
Despite the encouraging signs, details remain unconfirmed regarding whether the large tortoiseshell will become widespread across multiple landscapes in the UK. Richard Fox noted, “We’re still in that zone of uncertainty at the moment, but there are exciting signs,” indicating that while the situation is hopeful, further observation is necessary.
The classification of the large tortoiseshell butterfly as a resident species is a significant achievement for conservationists and a testament to the resilience of nature. As efforts continue to monitor and support this species, the future looks promising for the large tortoiseshell in the UK.
