A savannah elephant in Amboseli National ParkThomas Mukoya

Samuel Wasser has noticed that the tusks are getting smaller.

Since 2005, he has been helping customs officials analyze the vast quantities of illegally smuggled elephant ivory that circulate around the world. Such shipments are on the rise, and more than 40 tons are seized every year. At the same time, the average size of the confiscated tusks has fallen; having killed off many of the largest elephants, poachers are now turning their attention to younger individuals.

For example, Wasser, who is a conservationist at the University of Washington, recently investigated a seizure that comprised 1,800 tusks, most of which were under two feet long. A hundred or so were barely longer than a pencil, and hollow on the inside. Each one belonged to a calf who was just a few years old, and still dependent on its mother’s milk. Every pair represented a life that was ended for the sake of piddling amounts of ivory.

Elephant poaching really took off during the last decade, and it’s estimated that 111,000 individuals—up to a fifth of the full African population—have been killed since 2006. The slaughter is a local problem, but it eventually ties into organized crime networks that ship the plundered ivory around in huge containers that weigh half a ton or more. Once they leave port, these shipments are very hard to find. “There are so many containers on cargo ships that even the most sophisticated ports can inspect just 1 to 2 percent of them,” Wasser says. “If you’re a transnational criminal, you really just have to get your contraband into a container on a ship, and there’s a very low chance someone will find it in a search. We need to stop the trade before it enters into transit.”

To do that, Wasser first needed to find out where the ivory is coming from—and he began with poop. By collecting elephant dung from across Africa, and extracting DNA from them, he and his colleagues created a genetic map of the continent’s pachyderms. By cross-referencing the DNA from an unknown tusk to this map, Wasser can pinpoint the tooth’s source to within 200 miles. In this way, he showed that almost all the ivory that’s been seized in the last decade has come from just two poaching hotspots—one that includes Gabon and the Congo, and another centered in Tanzania.

But even with that knowledge, “poachers are very hard to catch,” says Wasser. “They work in very large areas, they know those areas very well, and they sometimes pay off rangers. And if you do catch them, there are ten other poachers waiting to take their place.” So, rather than targeting poachers, he says, it’s far more efficient to go after their customers.

Poachers sell their ivory to a pyramid of middlemen, who gradually consolidate it up to large export cartels, who then ship it out of Africa by the ton. It’s likely that these same cartels are funding poachers in the first place. “It costs between $25 and $30 for a bullet to kill a single elephant, so where are these poachers getting enough bullets to kill 1,000 animals?” says Wasser. It’s the cartels, “who are giving them purchase orders and quotas to fill.”

To him, these cartels aren’t just the core of the elephant poaching problem, but also its greatest vulnerability. If law enforcement officials could disrupt them, they could stem both the influx of arms and the outflow of ivory. To do that, they first need to know how many cartels there are, and where they operate. And Wasser recently discovered both bits of information, through a stroke of luck.

Whenever he and his colleagues would investigate a shipment of ivory, they’d try to pair the tusks up and, to cut down on costs, analyze just one from each pair. Pairing tusks is not unlike pairing socks: You do it by eye, looking for similarities in size, shape, and color. But the team noticed that in many seizures, over half of the tusks were unpaired. Where were their counterparts?

The team eventually found 26 cases where a tusk from one seizure perfectly matched a tusk from another. The matching tusks were almost always shipped from the same port within 10 months of each other, but they went out in different consignments. This suggests that tusks frequently get separated as they make their way from poachers to export cartels, even if they eventually end up in the same place.

“Connecting the tusks gives you a tremendous amount of information,” Wasser says. One pair might link seizure A to seizure B, and another might link B to C. “Now, you can start to see the size of the cartels and the connectivity between them.”

The team now thinks that just three major cartels, based out of Entebbe in Uganda, Mombasa in Kenya, and Lomé in Togo, were responsible for most of Africa’s ivory smuggling between 2011 and 2014. The Mombasa cartel is the biggest of the three, and is likely linked to the notorious ivory kingpin Feisal Mohamed Ali, who was arrested in 2014 and sentenced to 20 years. Ali was later acquitted on appeal, but Wasser hopes that the evidence from his tusk-matching work will help to build a stronger case.

The cartels are distinct entities, but they sometimes work together. For example, Wasser’s team identified one exceptional case in which the Mombasa cartel sent 4 tons of ivory from East African savannah elephants around the southern tip of the continent and up to Togo, where the Lomé cartel combined it with 2 more tons from ivory from West African forest elephants. Those 6 tons of tusks, stashed in 10 crates and split between two containers, was eventually shipped back around the cape. They were on their way to China, before they were intercepted in Malaysia in December 2012.

Two tusks from this shipment matched those from two later seizures in Togo, in August 2013 and January 2014. In the first of these, 0.7 tons of ivory were found in the warehouse of the alleged ivory trafficker Emile N’Bouke, who was arrested. It seems likely that he and his associates were responsible for adding all the forest elephant ivory to the 6-ton shipment that was seized in Malaysia. Wasser suspects that after N’Bouke’s arrest, his network tried to dump any extra evidence that could have been used against him. Their failed attempt led to the second Togo seizure in January 2014.

This kind of information, Wasser says, “becomes very useful when you get to the prosecution stage.” N’Bouke, for example, was convicted solely on the basis of the 0.7-ton seizure from August 2013. He was given the maximum permitted sentence of two years in prison and he is already out. If prosecutors could have proven that he was also involved in the earlier 6-ton Malaysian seizure, his sentence may well have been stiffer. “I’m not aware of any cases where the trafficker was charged for more than one seizure, and that’s something that could change,” says Wasser. For example, his results connect a Ugandan suspect who is awaiting prosecution for one seizure to at least two others.

“In a fair world, this would mean higher fines or longer sentences,” says Alice Catherine Hughes, a conservation professor at the Chinese Academy of Sciences. “But in the real world, those people are likely to be very well insulated, and might be able to pin [their crimes] on someone below them.” For that reason, she believes that the information from Wasser’s tusk-matching work will be “more academic than instrumental.” Still, the research “does provide more information about how many major cartels are operating, and which areas they’re operating in. Those areas are huge, but it gives us some idea of where to start doing monitoring.”

The DNA analyses “have been very successful in showing the connection between countries, and in getting all the partners to the table,” said John Brown, a special agent in the U.S. Homeland Security Investigations, in a press conference. “We have countries talking to each other [who] otherwise, wouldn’t have even picked up the phone.”

“There’s a lot of greedy people out there and they’re very clever,” Wasser adds. “It really requires a whole different approach to forensic science than what has been done until now.”

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