He was the consummate politician who could bend nations to his will, but Winston Churchill was powerless when it came to butterflies.
The British prime minister hired the country’s leading lepidopterist and spent years attempting to reintroduce two extinct species into his back garden.
Despite his best efforts, and the release of hundreds of black-veined whites and swallowtails in the 1940s, his schemes to have rare butterflies feasting on “fountains of honey and water” at Chartwell in Kent were an ignominious failure.
Churchill may, however, simply have been seven decades ahead of his time: new research has revealed that climatic conditions may be suitable for the black-veined white to fly in Britain once again.
The species – which is still found across much of Europe – became extinct in Britain after a series of disastrously wet autumns in the early part of the 20th century. Now, with average temperatures rising, experts believe it could prosper here once again.
Two studies in northern France, which has a similar climate to southern England, have found that it would be easy to provide for the black-veined white’s needs by creating flowery field margins and allowing the growth of young scrub such as hawthorn and blackthorn.
Fabrizia Ratto, from the University of Southampton, who conducted one of the studies for the charity Butterfly Conservation, said: “Our study found that the butterfly has a strong preference for small isolated bushes of blackthorn and hawthorn as egg-laying sites with abundant nectar sources such as red clover nearby.
“These habitat conditions can be recreated relatively easily in the UK through the implementation of agri-environmental measures such as nectar flower mixes in crop margins and by allowing some scrub regeneration beside adjacent hedgerows.”
The results of the studies are revealed at Butterfly Conservation’s international symposium in Southampton this weekend.
It is believed that Churchill became fascinated by the spectacular butterflies he encountered while serving as an officer in India. Unfortunately for him, his ambitious attempts to bring back the black-veined white were partly scuppered by his gardener, who accidentally hacked the nests of the young caterpillars from the hawthorn bushes where they had carefully been placed and burned them.
Churchill had no better luck with his attempts to bring the swallowtail back to Kent. Despite enlisting the services of the leading butterfly breeder of the day, L Hugh Newman, he could not persuade it to breed in the wild, and was again not helped by gardeners who burned the fennel which the caterpillars fed upon.
Churchill might have had more success today. While the British subspecies of the swallowtail is confined to the Broads of Norfolk and Suffolk, in recent summers climate warming has encouraged the continental subspecies of the swallowtail to cross the Channel, and several individual butterflies have bred successfully on carrot and fennel plants in gardens and allotments in Sussex.
Maverick attempts such as Churchill’s to reintroduce rare or extinct butterflies are frowned upon by conservation groups because they risk disrupting the scientific monitoring of species or introducing pathogens, but there is an increasing number of officially approved schemes to bring back scarce species. This summer the chequered skipper, which became extinct in England in 1977, is being returned to the forest of Rockingham in Northamptonshire via specimens from Belgium.
Of the possibility of bringing back the black-veined white, Prof Tom Brereton of Butterfly Conservation, who supervised the research, said: “We have so few butterflies in the UK, the return of one of Europe’s most spectacular species would be a major boost for everyone who loves butterflies. Creating habitat conditions for this butterfly would benefit pollinating insects and other valuable species, many of which are threatened by the impacts of climate change.”
While average temperatures look good for the black-veined white, experts say more research may be needed to determine whether the butterfly could survive the increasing frequency of extreme weather events that is a feature of our changing climate.