DNA evidence retrieved from elephant dung, tissue and hair can help identify the origins of illegal ivory, a new study finds. Researchers at the University of Washington and Interpol developed a method to extract DNA from samples of ivory, and compared the gene sequences with those obtained from dung and tissue samples.

More than 85 percent of the forest elephant ivory seized between 2006 and 2014 came from elephants innortheast Gabon, the northwest of the Republic of Congo, southeast Cameroon, and an adjacent reserve in the southwest of the Central African Republic.

The researchers found that more than 85 percent of the savanna elephant ivory seized between 2006 and 2014 came from elephants in East Africa. The findings could help target poachers: About 50,000 African elephants are killed each year, and the animals are at risk of extinction.