Using DNA to track poached elephant ivory

Fewer than half a million African elephants remain in the wild, and some 50,000 of these largest of land animals on Earth are slaughtered each year for their ivory tusks. That’s around ten percent of the population being lost to poaching each year. Reduce the demand for ivory and the motivation to kill elephants goes down, that’s basic supply-demand economics. But “one of the big problems with stopping demand is that it’s simply too slow,” says University of Washington researcher Samuel K. Wasser. “We need to do that in combination with other, more urgent tactics, which are primarily focused on stopping the killing of the elephants.”

One way to do that is by identifying the poaching “hotspots,” geographical locations in which elephant poaching is and has been occurring most frequently. Africa, after all, is a massive continent, larger in surface area than China, India, Japan, the continental U.S. and most of Europe combined. With all that space, conservationists and anti-poaching rangers can’t possibly monitor every elephant herd marching across the landscape. And even if they could, poachers are increasingly well funded and are therefore armed with impressive technology to allow them to find an elephant, tranquilize it, remove the tusks, and leave in a matter of minutes under cover of darkness.

The problem is that when tusks are seized by governmental agencies or conservation groups, they can be quite far from their origins. Many seizures are made, for example, in Malaysia, Singapore, the Philippines, Hong Kong, and other places far from the spots in which the animals were killed for their tusks. So Wasser and his colleagues from the University of Washington and INTERPOL developed a process that uses genetic data from seized ivory to estimate its origin.

Wasser and his team started by extracting genetic materials from 28 ivory seizures made between 1996 and 2014. Each seizure contained a minimum of half a metric ton of ivory, a statistic that’s unfortunately quite common. Such large seizures make up nearly three quarters of all ivory shipped since 2006. They compared the genetic data from the ivory to a database of pachyderm genetics taken from 1350 elephant dung samples, each from a single animal – 1001 savannah elephants and 349 forest elephants – from 71 locations in 29 different African countries. Their results were published yesterday in the journal Science.

What they discovered was that 27 of the 28 ivory seizures could be traced back to just four poaching hotspots. And seizures made in the past decade were comprised of ivory from just two places. “We were very, very surprised,” said Wasser.

They had to develop their own software to do it, and quality testing showed that they were able to assign a poached tusk to within 300 kilometers of its origin. In some parts of Africa, the spatial accuracy was actually far better, said Wasser.

For the smaller forest elephants, the critical hotspot is known as the “Tridom” (Tri-National Dja-Odzala-Mikébe) area, an ostensibly protected ecosystem that covers parts of northeastern Gabon, northwestern Democratic Republic of Congo (DRC), and southeastern Cameroon, plus the nearby Dzanga Sangha Reserve in southwestern Central African Republic (CAR). Six of seven seizures made of forest elephant tusks came from this area; the seventh included ivory from the Tridom area, but also quite a bit from West Africa, including Ghana and the Ivory Coast.

For the massive savannah elephants, the main hotspot for 15 of 16 seizures was centered in Tanzania, spreading just a bit into neighboring Mozambique. (The additional seizure, made in 2007, contained ivory from Zambia.) Until 2011, the majority of confiscated ivory was localized to an even smaller trans-border landscape in southeastern Tanzania and northern Mozambique, the Selous and Nyasa Game Reserves.

African elephants, Okavango Delta, Botwana. Copyright Art Wolfe.

African elephants, Okavango Delta, Botwana. Copyright Art Wolfe/

One important benefit of this genetic localization technique is that researchers can spot the movements of poachers as they decimate elephant populations and move on to fresh herds and territories, at least on a broad scale. Sometime in 2012 or 2013, savannah elephant poachers began to move several hundred kilometers northwest of the Selous and Nyasa reserves, into Tanzania’s Ruaha National Park and Rungwa Game Reserve, with some samples coming from even farther north. If the trend continues, the researchers suspect that the poachers will move towards southern Kenya.

By knowing that the clear majority of trafficked ivory comes from just a few places, anti-poaching and conservation efforts can be explicitly directed into those places, both to stop the killing of elephants and to hamper the ability of traffickers to move ivory into the world’s black markets.

The ivory, which ultimately destined for Asian markets, is “used mostly for small items, such as signature seals, jewelry, cigarette holders, and other items commonly weighing about 30 grams [on average],” said William Clark of INTERPOL’s Environmental Security Sub-Directorate, a co-author on the Science paper. Poachers stand to make enormous profits off of the raw material that eventually gets carved into those items. A typical piece of ivory in Africa sells for about $300 US dollars, so a single elephant with ten kilograms of ivory attached to its face will bring some $3000 dollars, which is “a fortune, especially for poachers.” That’s more than the per capita income for the areas in which most poachers live, just for killing a single animal. Once in the Asian markets, those trinkets can fetch more than $6000 per kilogram. It’s a $3 billion dollar per year enterprise.

It’s worrying that poachers could potentially make use of this sort of information and alter their habits to evade detection and law enforcement; the financial incentives for doing so are clear.

Wasser isn’t particularly worried about this possibility, though. “It may happen, but if it does, we will be able to detect it.” In part, that’s because a significant feature of these hotspots is the high-level governmental corruption that allows ivory to move out of a country without detection. Poachers won’t be able to rapidly create a new hotspot before that sort of infrastructure can be developed, he says. New CITES regulations, on the other hand, allow for the rapid turnover of ivory seizures for origin analysis. Wasser says that genetic samples from nearly 90% of all seizures made since 2013 that weighed a half ton or more are either already in his laboratory, are currently en route, or have been promised.

“This is a major transnational organized crime and the complex networks that drive it make this an extremely difficult problem to tackle,” Wasser says. On its surface, it seems like a fairly intractable problem. But “by identifying these major focused hotspots, this prevents countries that are involved in this trade from denying the extent of their involvement,” he hopes. And further, Wasser hopes that this sort of information will motivate the international community to collaborate on stopping the flow of ivory into these criminal networks. Indeed, in 1989 the international community succeeded at stopping elephant poaching in all of Africa for at least four years, thanks to the ivory ban.

Conventional detective work, such as attempting to follow paper trails, is no longer sufficient for understanding those complex networks, says Clark. Instead, organizations like INTERPOL are increasingly relying on more sophisticated, scientific methods like Wasser’s. Clark adds that by doing so, they can “establish investigatory priorities” and more efficiently plan their work.

Elephants are integral to Africa’s ecology. Savannah elephants allow the savannahs to remain savannah. Dozens if not hundreds of other species have come to rely on the elephants, either directly or indirectly through the impacts they have on the landscape. The forests of central Africa are critical for the planet’s carbon capture, just behind South America’s Amazon rainforest, and without elephants those forests could collapse. That would lead to serious problems in terms of climate change, public health, and food security. Then there are the economic concerns; eco-tourism is fundamental to the GDP of many African nations, and eco-tourism is driven by tourists’ ability to view elephants, rhinos, lions, and so on.

There’s quite a bit of complexity, but if anything is pure and simple it’s the bottom line. “If we do not curb the killings, we are going to cause serious problems throughout Africa,” warned Wasser. – Jason G. Goldman | 19 June 2015

Source: S.K. Wasser, L. Brown, C. Mailand, S. Mondol, W. Clark, C. Laurie, B.S. Weir. (2015). Genetic assignment of large seizures of elephant ivory reveals Africa’s major poaching hotspots. Science. DOI: 10.1126/science.aaa2457.

Header image: An ivory market in Central Africa, by Karl Ammann. Used with permission.