The Duke of Burgundy is back from the brink – and the work to conserve it has helped other declining species. Does this mean there is hope in the face of Insectageddon?

Giles Wood pauses on our walk in search of the elusive Duke of Burgundy. “Look at that hideous field of oilseed rape,” he says, peering from the Wiltshire Downs over the Vale of Pewsey. “For an artist, it ruins the summer for two weeks.” No yellow paint, says Wood, can do justice to its “nitrogen-enhanced meconium”. The vast field poses another problem that the painter, environmentalist and one half of Giles and Mary, the upper-crust bohemians from Channel 4’s Gogglebox, is acutely aware of. Despite the acres of nectar-bearing flowers, there are no insects in sight. Wood, who is a butterfly-lover, despairs. “What I really object to is the frequency of spraying [insecticides]. It gets everywhere, even into the fat of seals in the Arctic.”

Wood hopes to show me “the duke” – not one of his posh mates but a small golden insect that seven years ago was hurtling towards extinction in Britain. In 2012, it was found in 160 colonies. This sounds plenty, but 60% of these numbered fewer than 10 butterflies, and the species had vanished from at least 260 sites since 1980. Extinction experts observe how endangered species enter a kind of death spiral in their final years, beset by disease, climate breakdown and cruel twists of fate. And the duke – its distribution falling by 84% since the 1970s – was relentlessly spiralling down.

There is no direct connection between the prairie fields of oilseed rape and the duke’s decline, but the symbolism is strong. “Insectageddon” has entered popular vocabulary, describing the terrifying loss of insect life upon which, ultimately, the complex web of life on Earth depends. A survey on German nature reserves found that the abundance of flying insects declined by 76% over 27 years, leading to warnings of an “ecological Armageddon”. An analysis of global studies suggested earlier this year that more than 40% of insect species are declining. Although some scientists have criticised this particular study as too imprecise, there is ample precise data on British butterflies, which have been scientifically monitored since 1976. Here, chemical farming and climate breakdown are increasingly recognised as key drivers of decline: widespread butterfly species declined in abundance by 58% on farmed land in England between 2000 and 2009, despite a doubling in conservation spending.

In recent years, however, the duke has staged a miraculous comeback. Or rather, it has been revived by human action. Last summer, its numbers increased by 65%. This wasn’t a seasonal fluke: the butterfly has bounced back in Kent, revived in Sussex and is booming in North Yorkshire, where its long-term trend is up 71%.

“This is a species that has come back from the brink,” says Dan Hoare of Butterfly Conservation. “We’ve halted the slide towards extinction and in some landscapes it is genuinely marching back across the landscape. That’s a real cause for celebration.” Hoare, the director of UK conservation at this small charity, headed a programme to halt the species’ extinction in Britain. The duke’s caterpillars eat common wildflowers, cowslips or primroses, but the butterfly is oddly fussy: it doesn’t like the open downs favoured by most warmth-loving butterflies, nor does it thrive in dense woodland. It requires lightly grazed grassland and scrub, or coppiced woodland.

Facebook Twitter Pinterest A closeup of the duke. Photograph: Iain H Leach/Butterfly Conservation

Conservation scientists began to save the duke by first assessing the reasons for its disappearance from former haunts: 57% of extinctions were caused by “lack of management” – too-shady woodlands or too-scrubby grasslands. But 27% of extinctions were caused by “excessive management” – grassland grazed too heavily, or cleared of scrub. Ironically, these clearances were often funded by well-meaning conservation schemes to ensure that flower-rich chalk grassland remained free of bushes and trees. As Hoare puts it: “The duke doesn’t like the way our conservation effort is funded, with grants awarded every 10 years to remove all scrub in one go. That’s disastrous – dukes want scrub-removal little and often.”

When I call Dave Wainwright, who coordinates Butterfly Conservation’s efforts to revive the duke in North Yorkshire, he is resting beneath a tree after reaching “three figures” for dukes in a single day for the first time in his life. “After last summer’s drought, the caterpillars’ foodplants were wilted and I was predicting all sorts of horrors this year, but I’m counting very, very good numbers,” he says.

The effort to save the Yorkshire dukes began in the early 00s, with areas of hawthorn scrub cleared from steep-sided valleys to create a mosaic of suitable cowslip-rich grassland. Woodlands were also coppiced. The key, says Wainwright, was to connect existing habitat to new areas. Volunteers have also been crucial, monitoring numbers to show where the management is working and where it isn’t. Esme Walton, 80, from Helmsley, North Yorkshire, encountered the duke while out walking one day, and began volunteering to record its numbers every week over the summer as part of the national UK Butterfly Monitoring Scheme. “This little creature just fluttered up under my feet and I was enchanted,” she says. “They look so fragile but they are very fierce territorial things. I’ve seen them chasing butterflies twice their size. I get quite side-tracked watching the little shows they put on, the males spiralling up and up into the air.”

Data collected by Walton and others has revealed that the duke is now moving on to new areas of scrubby grassland made suitable for it. This “landscape-scale” conservation, creating “corridors” through which wildlife can spread, is a contemporary conservation cliche, but the duke’s expansion is proof that this connectivity actually works. Corridors in North Yorkshire, Sussex and Kent are being used by these fussiest of animals.

This landscape-scale approach also helps the duke and other species adapt to the climate crisis. Dry spells imperil the butterfly by causing cowslips to wilt and die back before the caterpillars can feed up to maturity. Last summer was a classic example: eggs laid on hot, south-facing slopes failed as the plants died. But because the butterflies also laid eggs on cooler north- and west-facing slopes, their offspring are flying again this year.

Facebook Twitter Pinterest Tree pipits have benefitted from the conservation work. Photograph: Arterra Picture Library/Alamy Stock Photo

“‘Climate-proofing’ is common sense in a conservation programme,” says Hoare. “We’re anticipating more extreme weather events, and the only way to mitigate against that is to build big, well-connected populations that are able to move around and respond.”

The duke’s revival may be heartening, but can we really halt Insectageddon one species at a time? Phoebe Miles, a Natural England ecologist who works on the Back from the Brink programme, which is saving 20 endangered species and their landscapes, including the duke, says some individual species trigger emotional responses – leading to funding, volunteering and other action from the public.

“You get a lot further focusing on the beautifully named and beautiful-by-nature Duke of Burgundy than you would focusing on, say, fine-leaved sandwort, which would also benefit from restoring the duke’s limestone grassland habitat,” she says. “Single species conservation allows us to hook into human emotion, whether it’s wonderment watching a Duke of Burgundy hopping from flower to flower, or empathy and pity for the Cornish path moss, which persists at only two sites in Cornwall – about 0.16 square metres in total – and nowhere else on Earth. While it’s not beautiful or charismatic, the sheer valour and humility of the moss’s desperate fight for survival might just win our affection, and ignite our duty of care for other small, silent plants and animals.”

Besides, as Miles points out, every single species conservation effort has helped other species, from the RSPB’s resurrection of the cirl bunting, which also benefited skylarks and linnets, to saving the greater sage-grouse in the US and Canada. This single-species project restored sagebrush, one of the biggest communities of species in the western United States, and improved the fortunes of other declining species such as mule deer and the sagebrush sparrow. The work to save the duke is also benefiting the grizzled skipper, dingy skipper and green hairstreak butterflies, as well as adders and tree pipits.

Saving the duke has not, however, halted the decline of more widespread insects – the butterflies and bees that people notice are missing from their gardens. These disappearances are driven by “huge policy-level decisions with agri-environment schemes, neonicotinoids and other pesticides, atmospheric nitrogen pollution and climate change,” says Hoare, “and require government intervention, intervention in global markets and the lifestyle decisions of individuals. But I would passionately argue that the UK is better off for having the Duke of Burgundy. Species-based conservation offers hope and shows people they have a choice about the sort of world they want to live in.”

My tour of Wiltshire with Giles Wood is on an overcast day, and we fail to see any of “this punchy little butterfly”, as Wood admiringly calls it. Two weeks later, Wood triumphantly sends me a picture of a duke he has just spotted. Its return to England’s downs has a lesson for him. “Out of all the fog, it shows us that the future of the world’s wildlife entirely now depends on us.”

• This article was corrected on 28 May 2019. The total area of Cornish path moss is 0.16 square metres, not 0.16 square miles.