Traced. Police in Singapore traced this 2002 shipment to Malawi. But genetic analysis shows that the elephants were killed in Zambia.

B. Mutayoba

Poached Tusks Point to Killing Fields

Poachers are once again decimating African elephants. But a team of researchers is tracing confiscated ivory to particular African elephant populations. The new information should help direct law enforcement officials to poaching hot spots and may allow them to head off the slaughter.

Usually when illegal ivory shipments are intercepted, law enforcers can only target the smuggler and the importers who bring the goods to market overseas. Rarely can they link a shipment to the place where the elephants were poached. But now, scientists are matching DNA extracted from elephant tusks with certain elephant populations across Africa, thus identifying the areas where the elephants were killed. "Our method tells law enforcement officials, 'This is where you need to be looking for poachers,' " says Samuel Wasser, a conservation geneticist at the University of Washington, Seattle, and the lead author of the new study published in this month's Conservation Biology.

Wasser's team analyzed 5.9 metric tons of ivory seized in Singapore in 2002, which had been shipped from Malawi via Mozambique and South Africa. The haul included 532 large tusks and 42,000 carved cylindrical signature seals, called hankos. Before that seizure, police had also raided an ivory factory in Malawi, collecting more than 100 ivory scraps left over from carving hankos. "We suspected that the ivory scraps from that raid and the tusks and ivory hankos in Singapore came from the same population of elephants," says Wasser. His team also analyzed 3.5 metric tons of ivory seized in Hong Kong in May 2006, as well as one small ivory chip found in a shipping container in Cameroon; they believed that these two were also connected.

The DNA analysis confirmed the researchers' hunches. Wasser's group then searched for a match between the ivory and elephant populations in Africa, using a database based on scat and tissue samples collected across the continent. They found that the Singapore and Malawi shipments came from savanna elephants in Zambia. The Hong Kong–Cameroon ivory, on the other hand, came from forest elephants along the border between Gabon and Congo-Brazzaville.

Documents from the Malawi factory indicate that it had made some 19 similar shipments over the preceding 3 years, says Wasser. If each had been about the same size--5.5 metric tons in weight--then some 17,000 adult elephants in total were killed, he estimates. His analysis for the Hong Kong–Cameroon shipments suggests that 5500 elephants were poached. Wasser says the soaring price for ivory--now worth as much as $850 per kilo wholesale--is fueling this round of killing, which he argues is worse than that of the 1980s.

"Wasser is doing what's needed, figuring out where on the ground the poaching is happening," says Ken Goddard, director of the U.S. Fish and Wildlife Service's Forensics Laboratory in Ashland, Oregon. Iain Douglas-Hamilton, a researcher with Save the Elephants in Nairobi, Kenya, says the approach is "new and very important" and should help direct law enforcement to poaching hot spots before all the elephants are killed.