Does the stork’s return to Britain restore history or rewrite it?

DIAL POST, England — The noisy throng of birds beat their wings and hopped up and down in their pen. These 3-month-old white storks, fueled by a generous morning’s feed, were ready for takeoff.

As a keeper twisted open the gate of the pen, a dedicated crowd of bird-watchers in stork-themed shirts held its collective breath from several hundred feet away. The sight of a juvenile stork on its first flight is not to be missed.

The lanky bird, fabled in European folklore as a bringer of life, is now a permanent addition to Britain’s skies. It is also a surprisingly contentious one.

To the conservationists behind the yearslong effort to establish a population, the storks’ introduction restores a species that was presumed to have been wiped out in Britain some 600 years ago. To some more skeptical naturalists, it is a misguided act that introduces a bird that had never made Britain its home.

The White Stork Project, as the effort is known, has so far established a colony of some 100 birds at Knepp, a 3,500-acre former dairy farm in West Sussex.

Over two decades, the environment has done most of the reclamation there unaided as part of a wider “rewilding” effort that lets natural processes govern the landscape. But Isabella Tree, the conservationist who co-owns Knepp, is giving it something of a push with the storks.

Unlike other birds that could strike out and breed from just one pair, storks are a sociable species that are more likely to survive in a colony, she said.

To build that colony, conservationists have released captive-bred storks at Knepp every summer for the past eight years. The effort is working: Some 40 nests silhouette the landscape’s oak canopies.

Related

More

This year’s batch of fledglings was bred at a zoo from flightless birds that had crashed into electrical pylons in Poland. After mingling with the colony’s existing population of wild-hatched chicks, the juveniles are embarking on a 1,000-mile seasonal migration to northern Africa this fall. It is a grueling voyage: Most typically die in the attempt, but survivors will return three or four years later to find a mate.

Tree’s hope is that the colony will eventually become self-sufficient and spread across southern England to form satellite colonies. “We know that we can bring them back,” she said in an interview in July.

As the colony has grown, so has a reexamination of the archaeological and written record of its existence.

Though white storks have been spotted in Britain over the centuries, some researchers say there is little sign they made more than fleeting visits.

“We have no evidence from any source whatsoever that there were ever areas in Britain with a significant stork population,” said Ulrich Schmölcke, an archaeologist who specializes in birds at the Leibniz Center for Archaeology in Mainz, Germany.

By that logic, Knepp might be Britain’s first white stork colony ever.

The question has opened a ferocious debate over how actively conservationists should reshape the wilderness.

Archaeologists have unearthed the occasional adult white stork bone in Britain, but they have never found juvenile remains that would show the birds were not just visitors, Schmölcke said.

Nor do white storks appear in Britain’s rich canon of folk tales or written laws, he pointed out, as they do in parts of Europe where they are unquestionably native breeders.

The evidence, Schmölcke said, suggested “they never established a stable population.”

Ian Carter, an ornithologist who previously worked with the official environmental body Natural England, objected to the managed release of white storks on that basis. “No matter how many times people say it’s a ‘reintroduction,’ it absolutely isn’t,” he said.

The birds could pose a threat to existing wildlife, because they breed in high densities and prey on vulnerable wetland creatures, Carter said. “You can’t impose a species on the environment without having knock-on effects on other species,” he added. “And it changes the meaning of wildlife if you can just pick and choose any bird.”

The uproar prompted Natural England to weigh in with an assessment. In May, it said it had determined that white storks were never a native breeding bird.

Although the birds had visited from continental Europe, researchers could locate only a single historical reference to a nesting pair: In 1416, a Scottish priest observed two white storks building a nest on the roof of St Giles’ Cathedral in Edinburgh before they flew off. It was not clear from the text whether they bred successfully.

“It’s an animal that has turned up here sporadically,” said Tony Juniper, the chair of Natural England. “But we can’t convince ourselves yet that this was an established species.”

While Juniper was effusive about the broader effort to “rewild” Knepp with native plants and other animals, he said environmental authorities could not actively support the introduction of a species without an established breeding history in Britain.

Sponsored

In response to the skeptics, Tree said the standard of evidence they demanded — juvenile remains or legal records mentioning breeding — was impossibly high.

Storks were part of medieval Britain, she said, pointing to their appearance in artworks and place names. One is Storrington, a village near Knepp.

“Ultimately, you can argue either way,” Tree said. “And I don’t think it matters.”

Bringing the birds to England has justifications beyond historical rectitude, Tree said. The storks’ large nests provide homes and food for other birds, she said. And the storks benefit from access to a cooler climate as continental Europe warms.

“We need to allow species to be able to move north in response to climate change,” she said.

While Tree’s critics contest her rationale, their objections are not a serious obstacle to her work. The releases at Knepp are independently funded and do not require official permission.

Juniper and Schmölcke both said that storks from mainland Europe could push north into Britain as the climate changes, regardless of the effort at Knepp.

At the estate in July, debates over their presence did not seem to concern the young storks as they took flight. Humans may have started the colony, but the birds did what feathered creatures tend to do. One by one they emerged from the pen, outstretched their wings and, after a few false starts, took flight.

Days later, the birds had embarked on their migration across the English Channel. Within weeks, some had been spotted in Morocco, scavenging in a garbage dump.