DNA detectives blow open the global ivory trade with incredible discovery

The African forest elephant was just deemed "critically endangered"
Grant Currin
DNA detectives blow open the global ivory trade with incredible discoveryiStock / wanderluster

According to a bombshell report published Monday, there could be just one — or perhaps a few — criminal organizations behind nearly all of the illegal ivory trade.

Researchers outline their findings in the journal Nature Human Behavior, writing they used DNA from 4,320 elephant tusks from 49 different seizures to figure out when tusks from close relatives were included in separate poaching shipments. The results show that elephants poached from the same family groups are frequently smuggled in shipments that had previously appeared to be unrelated.

"...a handful of networks are behind a majority of smuggled ivory"

"These methods are showing us that a handful of networks are behind a majority of smuggled ivory and that the connections between these networks are deeper than even our previous research showed," says University of Washington biologist Samuel Wasser. He led the team behind this work.

Their findings could help shape policies to slow the population decline in the African savanna elephant and the African forest elephant, which were listed as endangered and critically endangered, respectively, less than a year ago

Using genetics to untangle the illegal ivory trade

Elephant ivory is teeming with genetic information. All elephants have nearly the same DNA as each other. That high degree of similarity is what makes elephants, well, elephants.

But there are differences. In fact, every elephant (except in identical twins) has its own DNA, because genetic mutations pop up all the time during reproduction. Over long timescales, those mutations are the engine that drives evolutionary change.

They also make it possible to determine how closely related two elephants are to one another. That's because an elephant inherits nearly all of the variation in its DNA from its ancestors.

That makes genetic material rich in information, though that information isn't easy to understand. Geneticists have spent decades developing methods to figure out how closely individuals are related based on their DNA.

Wasser and his colleagues have spent more than two decades applying those methods to DNA found in elephant dung and tusks to find clues hidden in shipments of ivory that have been seized by law enforcement. 

That research has brought the illicit supply chain into much clearer view.

Mapping the elephant ivory supply chain

Initially, their work focused on determining where the elephants were being poached. Wasser and his team spent years collecting elephant dung samples and extracting DNA to build a map that shows the genetic geography of both forest elephants and savannah elephants.

That database of reference material has made it possible to trace ivory back to the population where it came from. That's turned out to be helpful information for law enforcement agencies and policymakers.

In 2009, the group used their new method to show that tusks in the largest ivory seizure since 1998, when the international ivory trade was made illegal, came from a sliver of southern Africa centered on Zambia. Before the analysis, law enforcement agencies had been operating under the incorrect assumption that the cache included tusks from across the elephants' range. The results led that country's government to improve its anti-poaching policies to reflect what was happening on the ground.

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In 2015, they reported that most of the ivory contained in 28 large shipments seized between 1996 and 2014 had also come from surprisingly small patches of elephants' range — and that the source was on the move. Shipments from the late 1990s and early 2000s had mainly come from Zambia. But starting in 2006, two new "poaching hotspots" became responsible for most of the supply of illegal ivory. The vast majority of ivory from savannah elephants came from an area straddling Tanzania and Mozambique. The vast majority of forest elephant ivory came from an area around Gabon, the Democratic Republic of Congo, and the Central African Republic.

Their picture of the illegal ivory trade came into a much clearer view a few years later when the researchers made another surprising discovery: large shipments typically contained just one tusk — either the left or the right — from each elephant. Most of the tusks in these shipments of 500 to 2000 tusks "lacked a pair," Wasser told journalists in a recent press briefing.

As they sampled more and more tusks, the researchers eventually noticed a pattern.

"Whenever the two tusks were in separate shipments, those two shipments always were moved out of the same port," Wasser says.

The vast majority of tusks were coming from just three ports: Mombasa, Kenya; Entebbe, Uganda; and Lomé, Togo.

That research "reveal[ed] connections between what would otherwise be isolated ivory seizures," he says. That made it possible to link seizures "not just to specific criminal networks operating in these ports, but to poaching and transport networks that funnel the tusks hundreds of miles to these cartels."

Looking for individual matches had its limits, though. In looking for exact matches, the researchers were trying to find a needle in a haystack. Since most ivory shipments aren't seized, they weren't working with much hay. Given the cost of genetic testing, it isn't feasible to examine all the tusks that end up in law enforcement agencies' hands. 

Uncovering family ties

This newest paper shows that the shipments are more tightly related than previously thought.

Instead of looking for DNA matches for individual elephants, the researchers used genetic clues to identify tusks that came from close relatives: parents and offspring or full and half-siblings.

"It was astounding what we found," Wasser says. "We had dozens of shipments that were tightly connected by multiple familial matches," suggesting it's "one big transnational criminal organization moving" all this ivory.

Evidence from more than 4,000 tusks seized in 49 different shipments between 2002 to 2019 show that while the ports where ivory is shipped have moved over time from Tanzania to Kenya and most recently to Uganda, the origin of most ivory is coming from the "same places in east Africa," he says. A similar pattern emerged in west Africa.

"What that suggests is either you have one large network that is moving all of that ivory out, or you have a very, very small number of networks that are very tightly connected," he says.

"It sounds horrible, but they may be waiting for elephants to go extinct."

The research is already changing how countries protect elephants and investigate poaching and smuggling. Wasser says one of the most important ways the information is being used is to prosecute smugglers for their entire operations, not just one shipment that happens to be seized, which he calls a "whack-a-mole" approach.

While the researcher didn't go into any specific cases, he noted that an alleged ivory kingpin was recently acquitted in Kenya because the evidence against him was too flimsy to prove the scope of his empire. DNA evidence from tusks could make a difference in future prosecutions.

Such information, combined with other sources of evidence, gives researchers deeper insights into the hidden dynamics of the ivory trade. Wasser says his team has come to one particularly gruesome conclusion, based on apparent disparities in how much ivory is exported and how much is ending up on the open market.

"What we really believe is that there are entrepreneurs that are buying these whole tusks, and they're actually stockpiling them... It sounds horrible, but they may be waiting for elephants to go extinct."

"They'll be able to make a fortune... when there [are] no more elephants," he says. 

With any luck, researchers' growing understanding of the illegal ivory market will contribute to the global effort to make sure that never happens.


Transnational ivory traffickers continue to smuggle large shipments of elephant ivory out of Africa, yet prosecutions and convictions remain few. We identify trafficking networks on the basis of genetic matching of tusks from the same individual or close relatives in separate shipments. Analyses are drawn from 4,320 savannah (Loxodonta africana) and forest (L. cyclotis) elephant tusks, sampled from 49 large ivory seizures totalling 111 t, shipped out of Africa between 2002 and 2019. Network analyses reveal a repeating pattern wherein tusks from the same individual or close relatives are found in separate seizures that were containerized in, and transited through, common African ports. Results suggest that individual traffickers are exporting dozens of shipments, with considerable connectivity between traffickers operating in different ports. These tools provide a framework to combine evidence from multiple investigations, strengthen prosecutions and support indictment and prosecution of transnational ivory traffickers for the totality of their crimes.

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