I OFTEN clash with my fellow conservationists, even though we have the same goals. I’ve always focused on species, whereas most of the conservation community look at ecosystems. For me, it all started with a love of birds of prey: as a schoolboy in rural Wales I kept and bred common kestrels in my garden.
When I was 20, I went to a conference on captive breeding at the University of Oxford, where I was inspired by the ornithologist Tom Cade. He said: “No birds of prey need become extinct – we have the capability to breed them and put them back into the wild.” He showed a picture of the Mauritius kestrel and said it was the world’s rarest bird but it could be saved.
I thought this was amazing: what I had been learning in my garden could help save the Mauritius kestrel. I was so fired up that I later went to the US to meet Cade and learn more about captive breeding. The trouble was that many conservationists believed that it was too late to save critically endangered species like the Mauritius kestrel. They were doomed, and the money would be better spent elsewhere.
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The World Wildlife Fund (WWF) and the International Council for Bird Preservation (ICBP) had a small Mauritius kestrel project, but were talking about pulling out. I was determined: through a contact, I persuaded Peter Scott, an ornithologist and head of WWF, to give me, a novice, the chance to go to the island in a last-ditch bid to save the species.
So in 1979, aged 24, I arrived in Mauritius. I was convinced we could breed and restore this endemic bird, even though there were only two breeding pairs left in the wild plus a few captive birds.
Things looked bad. In my first year, the captive birds got sick and died. We realised later that this was because the shed where we raised mice as bird food had been sprayed with the pesticide DDT during a campaign to rid the island of malaria. The mice were full of DDT, and eating them killed the birds. DDT was the reason the kestrel was rare in the first place.
I rethought how we were going to save the species and soon began clashing with the ICBP. They disapproved of my new approach, which was to take captive breeding techniques into the wild: removing eggs from nests for artificial incubation, killing predators, feeding the birds, providing nest boxes and so on. It was very intensive; I and a small team of local and international volunteers were often literally sleeping under the birds’ nests.
The ICBP, whose project was funded by the WWF, had a more hands-off approach. They wanted to protect the forests and set up an education project, but leave the wildlife to look after itself. Otherwise, as one of them told me, there was no point in saving it. We clashed badly, and they pulled out in 1984. I set up the (MWF) and found money from other sources, including Cade’s .
No quick fix
The birds soon responded to intensive management and their numbers steadily grew. But it was a long haul. I had realised almost as soon as I arrived that saving the species was not something that you could do in five years; it would be more like 50. If you dig into the recovery of the most endangered species – black-footed ferret, whooping crane, California condor and so on – they all show this pattern. It takes at least 10 generations. In the end, I spent 20 years full-time on Mauritius, and I still go back three times a year to follow .
We have used our techniques to save other endemic species on the island that would probably have gone extinct, like the pink pigeon, the echo parakeet and the Rodrigues fruit bat. I firmly believe that if we want to keep critically endangered species, we are going to have to look after them more or less permanently. That is a big challenge for the conservation community, which often acts as if we can return the world to its pristine state. That is total nonsense.
I soon realised on Mauritius that we were not just managing species intensively, but were also starting to manage ecosystems – restoring their functions, though sometimes using different species from those that were there before.
To restore ecosystems on the islands of Mauritius, we often had to rid them of invasive species like rats, goats and rabbits. But that created unexpected problems. For example, after we eliminated rabbits from Round Island, we expected to see the recovery of native tussock grasses and other endemic plants important for nesting seabirds and reptiles. Instead they started to disappear and we had to think again. I decided the system needed grazers. By getting rid of the rabbits, we had removed the only grazers still there.
The original grazers had been giant tortoises, until they went extinct. So I figured we should introduce Aldabra giant tortoises. They were a different species, but it seemed to me they would do the same job. When I talked to my friends about this, they all thought I was mad. “How do you know they will be an exact fit?” they asked. Botanists were literally purple with rage, saying the tortoises would eat critically endangered plants. I said: “Sure, that’s the idea. Your plants won’t survive unless tortoises graze on them.”
We conducted some studies that showed tortoises would do far more good than harm. It turned out that the seeds of endemic plants that passed through a tortoise’s gut germinated far better than if they hadn’t. After the MWF restored the tortoises, the native plants started to come back.
“The idea that the world can be returned to a pristine state is total nonsense“
The lesson is that we cannot turn back the clock on nature. With climate change, reconstructing ecosystems by design will be the only way to save them. What is important now is to keep all the component parts – all the species – for rebuilding. I am in favour of rewilding, but it will require more management, not less. This sticks in the craw of purists. What we did in Mauritius is still regarded by many as a failure, even though we now have 300 kestrels, because we continue to manage them rather than leaving them alone.
Our critics have to get real. It is only by taking the techniques of captive breeding into the field that we can be optimistic about saving species. I believe that with more aggressive approaches, we can save all species. Of course that will not happen in practice, but the conservation of most is within our reach.
This article appeared in print under the headline “Kestrel manoeuvres in the dark”
