Wildlife & Biodiversity

Not global warming: Reemergence of ‘extinct' black-veined butterfly in England likely due to unscientific release

Unregulated introduction disrupts actual conservation efforts and is condemned by scientists

By Preetha Banerjee
Published: Tuesday 06 June 2023
Photo: iStock12jav.net

Not everything unusual happening in our natural environment can be attributed to climate change and the recent sightings of a butterfly in England, where it was thought to be extinct, is a fine example.

The subtly beautiful black-veined white butterfly, known to be a favourite of former United Kingdom Prime Minister Winston Churchill, was once common in the British Isles. But it has not been spotted in the entire landmass since 1925, according to entomologists.  

Earlier this month, the butterfly was spotted by a correspondent of news organisation BBC, Frank Gardner, and some other nature enthusiasts, in south-east London’s hedges, according to a news report by the journalist. 

The news initially thrilled nature lovers and even some experts. But soon, conservationists announced that there is no reason to cheer. 

While Gardner didn’t make any link between the sighting and climate-change induced global warming, some other media reports mentioned a section of naturalists may be hinting at the correlation. 

Their assumptions, the reports have stated, are based on the fact that the species is still abundant in warmer territories outside the UK, especially on Europe’s mainland and northern Africa. 

“Naturalists are wondering whether the recent spate of warm weather may account for their reappearance,” a report on the website of British daily The Guardian stated. 

But the sightings may be a result of something slightly less ominous, but harmful nonetheless. “These sightings are the result of an unofficial release and it is unlikely the butterfly will survive in the wild to breed,” said Butterfly Conservation, a British charity that follows the distribution and population of butterflies in the UK very closely and also drives conservation efforts. They don't know who did this or why. 

The organisation said in an official statement: 

Undocumented releases confuse existing conservation efforts. They disrupt the recording of species’ natural ranges and trends, and Butterfly Conservation does not support these unofficial releases.

A more scientific approach will be to first ensure the places the butterfly lives are suitable for the long-term survival of the species, according to the non-profit.

In the past, similar unregulated release of butterfly species in territories they were thought to be extinct didn’t yield good results. 

Even Churchill appointed the UK's best lepidopterist in 1940 to help bring back the butterflies he loved to his garden in Kent, but the attempt wasn’t successful, according to The Guardian report. 

The butterflies have a wingspan of about 7 centimetres and the females have more transparent wings because they rub their wings against each other and shed scales in the process – a trait not found in the males. 

The species was first listed as British in 1667 and preferred the open grounds, according to an 1895 article in the journal Nature.

Just like its reappearance in the English countryside, its disappearance from its meadows and gardens a hundred years ago was a mystery, mainly because the plants it would feed on are still present in their previous habitats. 

Experts have various theories, right from unusual weather patterns such as a wet and chilly autumn or a relatively mild winter, disease or increase in predation. 

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