Ivory DNA test takes poachers to tusk

Illegal ivory tusks seized in Singapore in 2002 give reveal the scale of the poaching problem (Image: PNAS)Enlarge

Tools

A DNA test that reveals where ivory has come from has been used to pinpoint the geographic origins of hundreds of tusks seized from poachers, providing law enforcement agencies with valuable clues.

The test was developed in 2004 through a comparison of elephant DNA from different regions. Theoretically, it can pinpoint the origin of a particular sample to between 500 and 1000 kilometres.

Now, the DNA test has survived its first genuine challenge. It revealed that a huge sample of 532 tusks – seized in Singapore in 2002 but originally shipped from Malawi – came mainly from Zambia, not from multiple locations as originally suspected.

“We were delighted with the results,” says Sam Wasser, who developed the test at the University of Washington in Seattle, US. “The method actually performed better than expected.”

Unimaginable carnage

The results also showed that poaching was more widespread in Zambia than the country’s government had admitted. “The number of killed elephants was at least 30 to 60 times higher than Zambia indicated,” Wasser says.

The new results have helped Zambian police focus on poachers and traders in areas where the seized samples originated. “We’re now working closely with Interpol to analyse many other large seizures in this way,” he says.

Wasser adds that he has improved the geographic accuracy of the test after receiving additional samples, but gaps remain. “We are especially desperate for reference samples from the Democratic Republic of Congo and a few other areas where the carnage has been unimaginable,” he says.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0609714104)