Without Jones, the world might have lost the Mauritius kestrel, the pink pigeon, the echo parakeet and more – but the biologist’s methods are controversial

The last surviving bird of prey on Mauritius seemed doomed. In 1974, there were only four Mauritius kestrels left in the wild and attempts to breed them in captivity were failing. Extinction was “all but inevitable”, in the words of Norman Myers, one of the world’s leading environmental scientists.

Carl Jones, a biologist who arrived on the island in the 70s as an idealistic 24-year-old, remembers his employers, the charity that became BirdLife International, instructing him to “pull out elegantly” and leave the kestrel-saving to Mauritius government officials. “That actually meant closing it down, because the Mauritians didn’t have the resources or capacity for doing it,” he says.

What happened next on the island of the dodo is a source of inspiration in an age of extinction. Since 1970, humanity has wiped out 60% of mammals, birds, fish and reptiles, according to WWF, and one in eight bird species are threatened with global extinction. But Jones rescued the kestrel from oblivion, increasing its numbers a hundredfold, before going on to save more species than probably any other individual. Now the chief scientist at Durrell Wildlife Conservation Trust, the charity founded by Gerald Durrell, he has preserved many plant species and nine animals, including four other bird species that numbered fewer than 12 known wild individuals: the pink pigeon, the echo parakeet, the Rodrigues fody and the Rodrigues warbler. The 64-year-old has won the Indianapolis prize – the conservationists’ Oscars – but he is not an international celebrity, perhaps because his thinking challenges the conservation establishment.

There are few better guides to the Anthropocene – the era of the sixth mass extinction, in which we live – but Jones sighs at that phrase. “We definitely have to be aware of what’s happening, but we can do a lot to reverse these trends. All species are saveable,” he says. Even obscure insects? “I’m sure you can find examples where they are not saveable. I know this is very cliched, but you’ve got to start with solutions, otherwise you do nothing.”

He is still infuriated by Myers’ argument for wildlife triage – prioritising species more likely to survive at the expense of desperate cases such as the Mauritius kestrel. “Where does it end?” Jones says. “You can’t save rhinos? You can’t save elephants? There’s no room in the modern world for Californian condors? The worst is: ‘We don’t have enough money.’ How much money is there in the world and how much is wasted on trivial things? It’s such a defeatist argument.”

How do you save species? “It’s very easy. It’s no secret at all,” says Jones. We meet at the remote Welsh farmhouse he shares with his partner, his two young children, 6,000 books, a black-chested buzzard-eagle called Igle and countless skulls, remains and taxidermied animals he has encountered around the world, from giant tortoises and a huge grizzly bear to a polecat’s penis bone. “They talk to you after a while,” he says of his treasures. “A specimen is a repository for an infinite amount of information. You’ve got to live with your specimens, your animals. They’ve got to be part of your life.”

Facebook Twitter Pinterest ‘You’ve got to live with your specimens, your animals. They’ve got to be part of your life’ ... Jones among his stuffed giant tortoises and other wildlife curios. Photograph: Richard Jones/Guardian

Jones is tall, witty and imaginative, with “the admirable passion and zeal of an adolescent pigeon fancier”, as David Quammen put it in his book The Song of the Dodo. He embraces EO Wilson’s concept of biophilia, the human need to live intimately with other species. He has done so all his life and it has honed his hands-on approach to saving species.

His fascination with animals began in his earliest moments – soothed by an owl’s hoot in his cot – in rural Carmarthenshire, Wales. As a boy, Jones rescued injured wild creatures – badgers, tawny owls, kestrels – and bred raptors in homemade cages. “My headmaster always used to say: ‘Why don’t you do proper work instead of playing with the birds in your back garden?’ Deep down in my heart, I knew that breeding birds was something very special. When I learned about the plight of the Mauritius kestrel, I thought: ‘I can do that.’”

Jones challenges the classic conservation wisdom that we must first precisely understand the reasons for a species’ decline and then restore its habitat. Instead, he argues that scientists must tweak the limiting factors on a species’ population – food, nesting sites, competition, predation, disease – with practical fieldwork. “If there’s a shortage of food, you start feeding. If there’s a shortage of nest sites, you put up nest boxes. You don’t need endless PhD students studying a species for 20 years.” Conservation science, he argues, is often too remote. “Do you sit back and monitor a sick patient or do you treat them and see what works? A lot of species have been studied to extinction.”

In Mauritius, he used traditional captive-breeding methods developed by his heroes – Durrell and the conservationists Sir Peter Scott – “cosseting them in captivity and encouraging them to reproduce”. To this, he added new scientific methods to manipulate the birds’ productivity such as “double-clutching”, removing a kestrel’s eggs and hand-rearing the young to encourage females to lay a second brood.

There’s a great reticence to do hands-on conservation in Britain Carl Jones

Controversially, he also applied these techniques to wild birds, spending hundreds of hours camping beneath wild kestrel nests. “The most important thing when you start to work with a critically endangered species is to know that species with great intimacy,” he says. He trained wild Mauritius kestrels to take white mice; supplementary feeding encouraged them to lay more eggs. “By stealing those eggs and putting them in incubators, I could get them to lay second clutches. When I’d hatched eggs in captivity, I put some of the youngsters back in the wild and I fed the wild parents so they could look after them.”

Then, when he discovered that mongooses – brought to the island in 1900 to control rats – were raiding nests, he designed mongoose-proof nest boxes for safer wild breeding, trapped mongooses around nest sites and, if he encountered a mongoose during his fieldwork, killed it with his bare hands. His bosses were “very sceptical”, he says: “Traditional conservation is all about preserving animals and being hands-off. Here I was doing completely the opposite.” But his methods worked.

Jones worked on Mauritius throughout the 80s and 90s and still spends three months there each year. He used similar hands-on techniques to rescue the pink pigeon (now numbering 400 wild birds) and the echo parakeet (now 750) and worked with islanders on Rodrigues, 600km (370 miles) east, to restore lost forests, helping the Rodrigues fody and the Rodrigues warbler increase in number to 14,000 and 20,000 respectively. Some rarities still require “supportive management”, says Jones: the number of Mauritius kestrels has declined recently, although he is confident the population can be boosted with more nest boxes.

Facebook Twitter Pinterest Back from the brink ... a Mauritius kestrel. Photograph: Kevin Elsby/Alamy

Many conservationists view “single-species” conservation as trivial or expensive – an old-fashioned luxury in the 21st century. Jones argues that this is completely wrong. “Working with species is a key to unlock all the problems that you see in the system,” he says. Restoring a species revives an actor that performs a function – grazing or scavenging – within an ecosystem. “When you save an individual species you end up looking after the whole system.”

Jones’s species-saving has led to the restoration of whole systems. Round Island, a once-verdant islet near Mauritius inhabited by unique reptiles including the Round Island boa and Günther’s day gecko, was reduced to a moonscape by goats and rabbits released by sailors. These invasive mammals were removed to allow the flora to recover. Surprisingly, however, native plants found nowhere else in the world then started to decline. Jones decided to put the Aldabra giant tortoise, from the Seychelles, on to Round Island. “Everybody thought it was the worst idea in the world. They said: ‘You can’t do this. Extinctions on islands are caused by exotic animals and you want to put exotic animals on islands!’” Jones stressed that he would be restoring the ecological role of extinct giant tortoises. By the 90s, he had won people round. Now, 600 tortoises roam Round Island and native plants such as the ebony tree are thriving again thanks to the tortoises’ grazing and seed dispersal.

Facebook Twitter Pinterest Jones’s techniques have helped to raise the number of wild pink pigeons to 400. Photograph: Eric Nathan/Alamy

Jones thinks small islands are where we can begin to revive species. How would he revive Britain, one of the most nature-depleted countries in the world? After decades working overseas, the Durrell trust is planning collaborative projects to revive British wildlife. Restoring “ecological functions” with proxy species is an idea whose time has come: Konik horses are already used widely on nature reserves to mimic the grazing of extinct wild horses. One extinct European species is the great auk; Jones thinks a penguin species could be a proxy. “We should seriously assess the ecology of the great auk to see whether or not there is an appropriate penguin we could release in the northern hemisphere as its ecological replacement. We could reactivate the lost ecological interactions of the great auk. It’s a wacko idea, but it’s a lovely idea.”

Britain is pathologically nervous about carnivores, but Jones advocates slow, consensual rewilding and hopes eventually to reintroduce extinct wildcats to Wales. “If we bring wildcats to Wales, we’ll do it very gently. We’re not going to thrust it down farmers’ throats. We’ll do it by showing that wildcats won’t have any profound effects on farming practices and might even be beneficial, reducing rodent numbers and medium-sized predators such as foxes.”

Small islands could be ideal laboratories for larger carnivores. “I’m not necessarily saying we should put wolves and bears back into the Highlands, but we could certainly be thinking about putting them on some islands and large fenced areas.” He admits this is not perfect, but “it’s a way of getting them back into people’s consciousness, about seeing the beneficial impact that these species can have on systems”.

He would like to use captive breeding to save the turtle dove, the most rapidly declining European bird species, which could be lost from Britain within a decade. Big conservation charities, he argues, are “very risk-averse” and hide behind landscape-scale conservation schemes.

“While you’re doing big landscape stuff, the species can disappear and you can say: ‘Oh well, you know, these things happen,’” he says. “There’s a great reticence to do hands-on conservation in Britain. Think about your dying patient. You get in there and start looking after them, rather than standing back and watching them through binoculars.”