DNA testing on seized ivory shipments that reveals family ties among African elephants killed for their tusks is helping to identify poaching areas and trafficking networks at the center of an illegal trade that continues to devastate the population of Earth's largest land animal.
Researchers said they conducted DNA tests on 4,320 elephant tusks from 49 ivory seizures, totaling 111 tons in 12 African nations from 2002 to 2019.
The results could help crack the transnational criminal organisations behind the trafficking and strengthen prosecutions.
"These transnational criminal organizations we're trying to get - they are the key," said University of Washington biologist Samuel Wasser, lead author of the study published in the journal Nature Human Behaviour.
Most ivory is exported in large consignments - up to ten tonnes each - shipped as marine cargo and concealed among legal exports crossing oceans on container ships.
The DNA testing matched two tusks from the same elephant or, more often, tusks from close relatives found in separate containers for shipment in the same port.
Mr Wasser said the largest amount of ivory is now being smuggled out of Uganda through the Mombasa seaport, with ports in Kenya and Nigeria also often used. The ports used by smugglers have changed over time, he noted.
Previous research by Mr Wasser and his colleagues identified tusks from the same individual elephant that had been separated and smuggled by traffickers in different shipments prior to being seized by law enforcement at African and Asian ports.
The new research expanded the testing's scope to also identify tusks of elephants that were closely related, including parents, offspring, full siblings and half siblings.
The researchers used DNA from elephant faeces collected across Africa to compile a genetic reference map of various populations.
The new testing allowed them to identify the geographic location where the elephants were poached and also connect seized shipments to the same transnational criminal organizations.
Trafficking continues despite a worldwide ivory trade ban approved in 1989, with demand strongest in Asia.
Up to 2016, tusks were coming from elephants primarily from northern Mozambique north through Tanzania up to southern Kenya, Mr Wasser said.
Around 2016, there was a significant increase in tusks poached from a region twice the size of Britain called the Kavango-Zambezi Transfrontier Conservation Area that includes northern Botswana, northeastern Namibia, southern Zambia and southeastern Angola, he added.
This area is home to 230,000 of the remaining 400,000 African elephants, a population that includes two separate species - savanna and forest elephants. The study did not involve the world's third elephant species, the Asian elephant.
"There are about 415,000 elephants in Africa today, and we estimate that close to 50,000 elephants are being killed each year," said Mr Wasser, co-executive director of his university's Center for Environmental Forensic Science.
He said efforts made by law enforcement to connect one ivory seizure to others currently are rare, leaving cartels able to continue operating and rendering individual prosecutions vulnerable "for corrupt people in power in the country to sabotage the investigation."
