Scientists use DNA analysis to track elephant poaching networks

Friday, February 18, 2022

Cambodian customs agents pose with a cache of illegal ivory from Mozambique on December 21, 2016, seized in the same period as those in the study.
Image: Andyb3947.

Findings published Monday by a team composed mostly of University of Washington Center for Forensic Science researchers in Nature Human Behaviour report using a form of DNA analysis techniques originally designed for human teeth to track ivory poached from African elephants.

The scientists, in collaboration with the United States Department of Homeland Security, identified the criminal networks that killed the endangered animals and smuggled their valuable tusks across national borders.

The scientists took DNA samples from 4,320 tusks taken from both African bush (Loxodonta africana) and African forest (Loxodonta cyclotis) elephants that were confiscated from 49 separate ivory smuggling events in twelve countries from 2002 to 2019. The scientists found that teeth from the closely related elephants, or even two tusks from the same individual, often surfaced in different shipments that transited through the same ports. The data also showed when criminal networks shifted their operations from between port cities. They inferred poachers were making kills, then separating the tusks at some point along the smuggling route.

The team had been studying DNA analysis on poached tusks for years: in 2018, they found two tusks from different shipments had come from the same animal, which indicated both shipments were from the same kill and transited by the same criminal network. This is the first report of DNA identification tusks that came from elephants in the same families.

Lead author Dr Samuel Wasser said: "Identifying close relatives indicates that poachers are likely going back to the same populations repeatedly — year after year — and tusks are then acquired and smuggled out of Africa on container ships by the same criminal network." He added: "This criminal strategy makes it much harder for authorities to track and seize these shipments because of the immense pressure they are under to move large volumes of containers quickly through ports."

Wasser said similar studies will provide law enforcement groups access to a greater range of evidence with which to prosecute poachers and their criminal partners by providing verifiable links between different caches of captured ivory. The researchers concluded in their paper that law enforcement could use their information to discern the ways in which poachers are collaborating.

Humans have used the ivory from elephant tusks to make art, decorations, and tools since prehistory. Many countries have since outlawed the sale of ivory, but poachers continue to kill tens of thousands of elephants each year.

The paper's authors were from the University of Washington, the U.S. Department of Homeland Security, the U.S. Fish and Wildlife Service, Kenyan-based organisation SeeJ-Africa, the Kenya Wildlife Service, and Singapore's National Parks Board.