It was with a sense of great foreboding that Bronx Zoo herpetology curator John Behler complied with a mandate to return 33 young endangered ploughshare tortoises to the island of Madagascar in 1998. Behler had rescued the animals—less than half of those stolen from a conservation breeding colony in 1996—a few months earlier from a small zoo in the Netherlands, where the Dutch government had stashed them after an illegal exotic-pet dealer got cold feet. But Dutch commercial animal trader Olaf Pronk, who was well known for dealing in rare Malagasy reptiles, pushed the Madagascar government to sue to get the tortoises back.

“It became a messy legal battle,” recalls British conservationist Richard Lewis, director of Durrell Wildlife Conservation Trust’s Madagascar program, which originally bred the tortoises. “The Bronx Zoo was worried, rightly or wrongly, that the animals were going to just disappear again.”

A national Dutch court ruled...

Today, 14 years later, conservationists believe that at least 10 to 14 of those 33 tortoises are still alive. They are now just a couple years away from breeding age, and though the engravings are small relative to the size of the adult animal, they are still visible.

Of course it’s a shame that these beautiful animals have to be defaced, but it’s
done with their best interest
in mind.
—Rhett Butler,

“It was very controversial when he did it,” says Eric Goode of the Turtle Conservancy, which he cofounded with Behler, now deceased. On one hand, Behler’s actions defaced a beautiful and extremely threatened species. On the other, “he never wanted to have those animals enter into the trade.”

Goode, for one, is supportive of such practices, especially since the illegal pet trade continues to threaten the tortoises. “We’re at the brink with this species,” he notes. “Unless we take pretty radical measures it’s just going to go extinct in the wild.”

So Goode and his collaborators researched the exotic pet trade to determine the best way to deter smugglers. They even interviewed an infamous reptile dealer who served prison time for his involvement in the trade of Galapagos tortoises. “He basically said he would not buy [a marked] tortoise,” Goode recalls. “He [said] it was the kiss of death. If an animal is marked, especially with the initials of the government of origin, no one wants to take that and put that in their collection.”

Convinced it was a necessary step to save the ploughshare tortoise, Goode teamed up with Lewis in 2008 to start marking the shells of the animals at Durrell’s breeding colony in Madagascar, and more than 200 captive tortoises have been marked so far. The pair has also coordinated with locals, who started finding, marking, and releasing wild tortoises in January.

Like Behler, the researchers are using a rotary tool to do the engravings, which consist of MG (for Madagascar) and a number. Though it may sound invasive, the technique appears to be harmless to the animals. Tortoise shells are covered with layers of keratin, like fingernails, and the ploughshare tortoise has the thickest keratin of any tortoise in which it’s been measured, allowing the conservationists to drill quite deep into the carapace without hitting the bone below. “They’re not showing any real signs of pain whatsoever,” Goode says. “You do it, and the tortoise will just go about its day.” (Tortoises less than 20 centimeters long are marked using a primitive tattooing technique, similar to that employed by prisoners, Goode notes.)

The big question, of course, is whether it will work. “It remains to be seen,” Goode says. Some people might still buy the animals to breed them, for example, or try to find a way to conceal the mark. Others may kill the animals out of spite, as has occurred in rhinos whose horns have been cut off. “There’s no perfect solution,” he says. “It’s not going to end the trade, for sure, but we think it will at least do a lot.”

Not surprisingly, “[the project] was met with a lot of resistance,” says Goode. Even project participants have fleeting reservations. In the end, however, it’s gained the support of the conservation community. “I certainly feel that what Durrell is doing seems to make complete sense and is warranted,” says Mal Mitchell of Azafady, a conservation-oriented charity with a presence in southeast Madagascar.

“Efforts like this are a good short-term strategy,” agrees conservation journalist Rhett Butler, founder of the rainforest conservation site “Of course it’s a shame that these beautiful animals have to be defaced, but it’s done with their best interest in mind.” Longer-term measures must also be taken to address the demand for such animals in the first place, Butler adds. “The obvious option would be establishing a captive breeding population for the pet trade, which would basically kill demand for wild animals.”

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