Genetic map pinpoints elephant poachers
DNA from tusks could help tackle ivory trade.
DNA from seized ivory could help conservationists and police identify hotspots where elephants are in particular danger from poachers.
Since the ivory trade was banned in 1989, elephant poaching in Africa has moved from the open savannahs into the dense rainforests, to avoid detection from aeroplanes overhead. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) now uses ground patrols to track poachers and search for elephant carcasses.
But patrolling the forests is slow and difficult, and killings can go unnoticed for years. The new DNA tool would immediately locate regions where elephants are at risk.
Sam Wasser, at the University of Washington in Seattle, and his colleagues studied gene variations in the DNA of elephant dung samples taken from 28 locations across Africa. They then mapped how the frequencies of different gene variations would be likely to vary for elephants from all over the continent. Their results are published in the Proceedings of the National Academy of Sciences1.
"Forest elephants live in communities that are very isolated from other elephant populations, so their DNA is unique," says Wasser. "We can tell apart elephants from different forests and savannahs in west and central Africa with an accuracy of almost 100%." There is more gene flow between east and south African elephant populations, but Wasser says the test can still identify the location of these populations 80% of the time.
Wasser is using his gene map to help Interpol trace the origin of seized ivory, by comparing DNA from the tusks with the DNA found at different locations on the map. His efforts are welcomed by other ivory trackers, such as Tom Milliken of TRAFFIC, a wildlife trade-monitoring network that works alongside CITES.
Milliken, who reconstructs the path of illegal ivory from the paper trail of documents that accompany shipments, explains: "The brightest window we have is on the endpoint, the ivory market. But the largest uncertainty in our chain is where it is coming from, and this method will help with that."
However, Milliken cautions, the method will not provide an easy solution to elephant hunting. Most poaching occurs in the Democratic Republic of Congo, where civil unrest has displaced refugees into protected wildlife areas, leading starving people to hunt elephants for food.
"DNA can tell us where the elephant was killed. But, unlike patrols, it can't tell us why it was killed," says Milliken. "If ivory is a by-product of a food trade, then we need to deal with the hunger first."
Milliken will be speaking at CITES's biennial meeting next month. He plans to stress that the best way to combat the ivory trade is to put pressure on the market countries, China and Thailand in particular, who buy the ivory for jewellery products.
Wasser will not be attending the CITES meeting. But because he needs more dung samples to improve the accuracy of his map, he does have a message for participants: "We're crying to CITES, please, this is such an important method for you to use. It costs you nothing. The patrols are already out there; so please, just ask them to pick up the poop."
- Wasser S. K., et al. Proc. Natl. Acad. Sci, (2004).