Reference Article: Harper, C., et al. (2018). Robust forensic matching of confiscated horns to individual poached African rhinoceros. Current Biology. 28(1), R13-R14. https://www.sciencedirect.com/science/article/pii/S0960982217314501
When you think about African wildlife, chances are that rhinoceroses are one of the first species that come to mind. Rhinos, however, are not just iconic examples of savanna fauna. Rhinos also act as both ecosystem engineers and keystone species, structuring their environments by knocking down trees, flattening shrubs, and keeping forests from taking over grasslands. Though the black and white rhinoceroses, Diceros bicornis and Ceratotherium simum, respectively, are vital members of savanna communities and adult rhinos do not have any natural predators aside from humans, their populations are dwindling due to illegal poaching driven by the horn trade. Unfortunately, the slaughter of African rhinos has become more frequent in recent years despite strictly enforced legislation that bans the trade of rhinoceros products. Because of this, African law enforcement officials have teamed up with wildlife rangers and genome scientists to make a forensic connection between confiscated products and specific crime scenes. By implementing a DNA-based protocol for identifying the individual rhino from which a confiscated horn was extracted, authorities have stronger evidence to support criminal investigations against poachers.
The DNA-based protocol that has been employed includes the identification of 23 highly variable short tandem repeats – a sort of DNA fingerprint unique to each rhino – for 4,000 individuals within black and white rhino populations. A database known as RhODIS® (Rhinoceros DNA Index System) has been created to compile genotypes of rhinos sequenced from confiscated horns and samples from living specimens. In addition to optimizing genotype panels to identify individuals, researchers have developed RhODIS® to include genotypic and demographic information (like age and sex) for over 20,000 different rhino acquisitions, analyzed population genetic structure of both species of rhinoceros, and determined the probability of match for profiles from both species. Finally, through this work, a reference database including 883 black rhino genotypes and 3,085 white rhino genotypes has been established. Population genetic analyses have identified one subspecies of white rhino and three of black rhinos, as well as traceable differences in the genomes of populations from different locations.
The ability to match confiscated rhino products to known poaching crime scenes has resulted in stronger cases against poachers. Since 2010, there have been more than 5,800 crime cases submitted to RhODIS®, including over 120 reports in which investigators have been supplied with carcass material that has been related to evidence. Through RhODIS®, several suspects have been prosecuted, sentenced, and convicted of participating in illegal hunting of rhinoceroses through forensic matching of evidence items to individual crime scenes.
The application of forensic evidence to poaching cases provides important links between the crime scene and its victim. It also adds an additional layer of support to prosecution of poaching suspects. What, though, does this mean in the grand scheme of rhinoceros conservation? It means that people who have been accused of poaching will have a far more difficult time getting away with their crimes. It does not, however, mean that rhinoceroses are safe. There is still much to be done to protect the rhino, and, thankfully, there are many individuals working to make their ranges safer. Public awareness remains incredibly important. Though poaching is often motivated by profit, there are also cultural components to illegal wildlife trade, and multifaceted approaches to conservation must be considered.
For More on the Rhino
For more information on rhinoceroses and the steps being taken to conserve them, check out the African Wildlife Foundation’s page on rhinoceroses at https://www.awf.org/wildlife-conservation/rhinoceros, and this article from Smithsonian Magazine that highlights their role in the environment https://www.smithsonianmag.com/articles/heres-what-might-happen-local-ecosystems-if-all-rhinos-disappear-180949896/.