Over the past 50 years, lion numbers have decreased by three-quarters. Only 20,000 to 40,000 of these majestic big cats survive in the wild today. A third of lion deaths are a result of poaching, and even where lions are killed in retaliation over livestock predation, in many cases their body parts are harvested for sale.
Wildlife crime investigators face a big handicap when dealing with confiscated wildlife products. Sifting through dismembered remains — claws, bones, teeth — it is hard to say where they originate from.
To trace lion parts to their source populations, researchers at the University of Illinois Urbana-Champaign developed a web tool, the Lion Localizer, which uses DNA testing to pinpoint the geographic source of contraband lion parts.
“Currently, the origin of most lion products is unknown,” said Rob Ogden, director and co-founder of TRACE Wildlife Forensics Network, a partner in the Lion Localizer project. The U.K.-based nonprofit, which supports the application of forensic science in wildlife law enforcement and works in at least a dozen African countries, is trying to change that.
Barring a small population in India, these big cats (Panthera leo) are only found in Africa. Technically, there are two extant lion subspecies: the northern lion (P. l. leo) and the southern lion (P. l. melanochaita). The former includes populations in Asia and those in Central and West Africa, while the latter includes lions in Southern and East Africa.
DNA samples from confiscated parts are already used to identify species. This is key because to prosecute wildlife criminals, it’s necessary to show the contraband comes from protected wildlife. To pinpoint which population of a particular species takes investigations a step further. It may not directly contribute to proving illegality, but it deepens forensic intelligence into how the wildlife trade operates — knowledge that can aid conservation and management efforts.
While the East African lion population numbers in the thousands, fewer than 500 lions remain in the wild in West Africa. “The West African lion population is tiny, and it’s really, heavily threatened. We cannot afford to lose any,” Ogden said in a statement. “If a product is coming out of East Africa, then it might not be so critical in terms of population numbers, although law enforcement still needs to know about it.”
In a paper on the Lion Localizer in the Journal of Heredity, its creators called the tool a “valuable resource for combating lion poaching, by rapidly identifying populations that are newly targeted, or that are being targeted most aggressively by poachers.”
The DNA of individuals belonging to a species is nearly identical, but there are differences. These variations in their genetic code can distinguish one population from another of the same species.
Users of the Lion Localizer need to extract and sequence a slice of cytochrome b, a region of the mitochondrial DNA (mtDNA). Once they input that sequence in a web form, the tool compares it against fragments of mtDNA in a database. This repository includes sequences from samples collected at 146 sites in 24 countries (African nations and India), which yielded 21 distinct haplotypes or genetic markers that are inherited together.
This set of markers link individuals in a particular geography. Offspring inherit mtDNA only from their mothers. For species like lions, because lionesses don’t disperse far from their natal lands, certain haplotypes can be tied to a geographic area.
“Various researchers who had published scientific papers on lion genetics, and their published mitochondrial DNA sequences were incorporated into the Lion Localizer database,” said Alfred Roca, who teaches courses on conservation and population genetics at the University of Illinois at Urbana-Champaign and is one of the principal architects of the Lion Localizer.
Source : Mongabay
