Poaching decimated African elephant populations from ~ 1.3 million to 500,000 individuals in the eight years between 1979 and 1987, prompting an international ban on new ivory sales. However, current poaching rates now exceed those prior to the ban.
This prompted the Convention on International Trade in Endangered Species (CITES) to list the African elephant as an Appendix I (endangered) species in 1989. Despite these protections, the illegal ivory trade is currently approaching its highest levels in history. Much of the demand for ivory is being driven by the growing economy in China and the prestige associated with owning ivory in that nation. However, the U.S. and Japan are also important sources demand. Increased demand in high paying industrialized nations has caused the price of ivory to soar. At the same time, liberalization of laws to promote global trade has made it easier for dealers to ship large volumes of illegal contraband without detection. Prosecutions of wildlife crime are virtually nonexistent, considered low priority relative to murder, rape, weapons, drugs and terrorism. Crime syndicates now flourish by taking advantage of this high profit low risk enterprise. The result of these combined factors is adding a whole new dimension to elephant poaching, causing elephant numbers to plummet at a rate of 8% annually—the highest rate in history, dramatically impacting elephant populations across Africa. This is clearly unsustainable.
Forest elephants suffer their own set of challenges. They are currently being slaughtered across central Africa because logging and road building have recently made elephants more vulnerable to bushmeat and ivory poaching. Worse yet, poaching in forests cannot be monitored by aerial surveys as in savanna habitat.
To address these problems, we developed a genetic method to track the geographic origin of poached ivory.
Our goal is to identify poaching hot spots and potential trade routes by determining the geographic origin of large volumes of contraband ivory seized by wildlife authorities. These large volumes bear the stamp of organized crime syndicates that can afford to lose millions of dollars if their cargo is seized. Identifying the origins of these large seizures helps reveal the strategies of poachers and where to focus law enforcement.
DNA is successfully isolated from small amounts of ivory, sampled anywhere along the length of the tusk (Fig. 1) and used to create a unique genetic “fingerprint” of each elephant. We also extract the same genetic information from elephant feces. DNA from feces enabled us to assemble a geographic-based map of elephant gene frequencies across Africa. We applied a novel statistical smoothing method to these gene frequencies to create a continuous distribution of elephant gene frequencies across the continent. This allows us to estimate each poached ivory sample’s position across Africa (Fig. 2), including areas with no reference samples, and provides a confidence estimate for each assignment.
We are now collaborating with the Interpol Working Group on Wildlife Crime and the Lusaka Agreement Task Force (LATF), using these methods to determine the geographic composition of major ivory seizures shipped from Africa to the Far East. We strive to improve the accuracy of predictions by collecting scat samples to fill the remaining gaps in the gene frequency map used to determine elephant origin. DNA extracted from feces provides a non-invasive method of rapidly acquiring these reference samples from across Africa.
Our first investigation identified the geographic origin of the largest ivory seizure since the 1989 ivory trade ban—6,500 kg of ivory seized in Singapore, June 2002, en route from Malawi. This shipment contained 531 tusks, many of which were atypically large (mean = 11 kg), suggesting it was targeting wealthy buyers. Small tusks were conspicuously absent. The shipment also contained 42,000 hankos (small solid ivory cylinders used to make individual seals for letters), representing 20% of Japan ’s annual hanko sales.
We also examined ivory scraps seized in a raid of an ivory carving factory in Malawi, two months prior. Confiscated records suggested these scraps might be from the same ivory that was cut into hankos.
The size of this seizure and the absence of small tusks led wildlife authorities to suspect that this shipment was assembled from multiple locations across forest and savanna Africa. However, our results showed that the tusks, hankos and ivory chips originated from the same location. All the ivory was from savanna elephants native to a narrow E-W band of southern Africa, centered on Zambia (Figure 4). This insight enabled law enforcement to focus their investigation on a smaller area and fewer trade routes, and led the Zambian government to significantly improved their anti-poaching efforts. It also explained the absence of small tusks in this seizure. Smaller tusks (from young elephants) were cut into hankos, increasing the overall value of the shipment.
Our second seizure began to uncover common strategies used by large syndicated dealers to traffic poached ivory. Nearly 4,000 kg of ivory were seized in Hong Kong, shipped from Cameroon. Hong Kong authorities using x-ray discovered the ivory in a false compartment of a container containing sawn timber.
They subsequently seized two more containers returning to Cameroon from Hong Kong, registered to the same shipper. False compartments were also found in these two containers. The compartments were empty, but a few ivory chips were found on the floor.
Our analyses showed that the tusks and ivory chips were from forest elephants of a common origin, centered on SE Gabon near the Congo-Brazzaville border.
Together, these two major seizures revealed that syndicated dealers were persistently hammering the same population over and over to fill their purchase orders. Results also revealed that the ivory was shipped from a different country from where it was poached as part of a risk reduction strategy. Traditional forensics evidence would never have detected that.
Our approach provides reliable information on where ivory poaching is most concentrated in Africa. Such information tells authorities where greater enforcement efforts are needed and helps to identify trade routes used to move ivory inside and outside Africa. Results also create accountability by forcing nations to be more responsive to poaching in their country.
Information gathered from these analyses, and associated increases in seizure rates, should enable international authorities to more effectively evaluate the consequences of future trade decisions.
Traffic in forest elephant ivory can also be used to indicate hotspots in the burgeoning bushmeat trade across central Africa . These methods may be among the only reliable means to monitor trade in forest ivory and bushmeat because poached carcasses are difficult to detect in dense forests.
Additional uses include:
- Detecting whether declared government ivory stockpiles are being sold off and illegally replenished.
- Detection of illegally traded tusks from other countries in sanctioned ivory sales.
Similar methods could be readily applied to other wildlife crimes as diverse as the illegal trade in timber or tiger parts.
Wasser, SK, J Poole, P Lee, K Lindsay, A Dobson, J Hart, I Douglas-Hamilton, G Wittemeyer, P Granli, B Morgan, J Gunn, S Alberts, R Beyers, P Chiyo, H Croze, R Estes, K Gobush, P Joram, A Kikoti, J Kingdon, L King, D Macdonald, C Moss, B Mutayoba, S Njumbi, P Omondi, K Nowak. 2010. Elephants, Ivory, and Trade. Science 327: 1331-1332.
Wasser, SK, B Clark, C Laurie. 2009. The Ivory Trail. Scientific American: 68-76.
Wasser, SK, WJ Clark, O Drori, ES Kisamo, C Mailand, B Mutayoba, M Stephens. 2008. Combating the illegal trade in African elephant ivory with DNA forensics. Conservation Biology 22: 1065-1071.
Mailand, C., SK. Wasser. 2007. Isolation of DNA from small amounts of elephant ivory. Nature Protocols 2: 2228-2232.
Wasser, S, C Mailand, R Booth, B Mutayoba, E Kisamo, B Clark, M Stevens. 2007. Using DNA to track the origin of the largest ivory seizure since the 1989 trade ban. Proceedings National Academy of Sciences 104: 4228-4233.
Wasser SK, A. Shedlock, K. Comstock, E. Ostrander, B. Mutayoba, M. Stephens. 2004. Assigning African elephant DNA to geographic region of origin. Applications to the ivory trade. Proceedings National Academy of Sciences 101: 14847-14852.
This research is being funded by grants from the U.S. Fish and Wildlife Service Elephant Conservation Act, the International Fund for Animal Welfare and the Bosack Kruger Charitable Foundation. This study is being conducted in collaboration with several government agencies and NGO’s, including: Interpol, Lusaka Agreement Task Force, WCS, WWF, CITES MIKE, and Sokoine University of Agriculture.