In the thankless fight against the poaching and slaughter of rhinos on the African continent, conservationists and law enforcers have a powerful new tool at their disposal. By developing a DNA database of rhinoceroses, investigations are now able to link the suspected poacher to a crime scene, and sometimes the exact rhino carcass that a horn came from.
This astonishingly precise methodology, known as the Rhino Index System (RhODIS®), has now been used in over 5,800 forensic cases and has managed to directly link horns, blood-stained items, and even the carcasses of poached rhinos discovered by wildlife rangers in over 120 of these cases.
A new paper published in Current Biology has looked in detail at how the system has been used to provide direct evidence of rhino poaching that enabled the successful conviction of nine people, one of whom was put behind bars for 29 years.
“Unlike similar work in which genetic databases provide an indication of geographic provenance, [the rhino DNA database] provides individual matches that, similar to human DNA profiling, is used as direct evidence in criminal court cases,” explained the University of Pretoria’s Cindy Harper, coauthor of the study.
Amazingly, the new database can help law enforcement not only trace exactly which carcass a seized horn has come from, but can also be used if the horn has been ground down, or if someone is arrested and the clothes or other objects they have are splattered in blood. In South Africa, evidence gathered from the clothes of a suspected poacher was used to sentence the accused to eight years in jail.
The DNA testing works by using sampling kits that can be used by rangers, police, and scientists. It then looks for 23 short tandem repeat (STR) loci in the genome, which the researchers showed by sampling almost 4,000 rhinos, can be used to reliably match any tissue samples, including carved curios and powdered horns, to the actual animal.
One of the biggest hurdles to overcome is the rapidity in which poached horn is hacked from the rhino and then smuggled from the crime scene to the markets in East Asia. This means that police and law enforcers have to communicate and cooperate internationally. Amazingly, however, this has not been too major an issue.
“Thanks to this support, we've seen rapid growth of the database into a representative source of rhinoceros genetic data for both forensic and management applications from its inception,” said Harper. “The unprecedented cooperation and support for the program from these authorities has been surprising and encouraging.”
As more and more samples are added, the database will continue to grow, providing even more detailed data, as well as vastly increasing our knowledge of the animals.