Evrim Yazgin
Cosmos science journalist
DNA extracted from between the teeth of 2 Kenyan lion specimens from the 1890s shows that the animals ate humans, as well as giraffes and wildebeests.
The pair of male lions were dubbed the “Tsavo Man-Eaters” and are thought to have eaten dozens of people, including workers on the Kenya-Uganda railway in the late 19th century. Some estimates suggest they killed more than a hundred people.
Both lions were killed in 1898 by Lieutenant-Colonel John Henry Patterson. He wrote a book about the hunt called The Man-eaters of Tsavo.
In 1924, the lions’ skins were sold to the Field Museum of Natural History in Chicago, US where they are displayed alongside their skulls.
To put the legends to the test, a team of US and Kenyan scientists analysed hairs collected from between the teeth of the pair of big cats. The findings are published in the journal Current Biology.
“As biotechnologies advance, there are unexpected sources of knowledge, in this case genomics, that can be used to inform about the past,” says senior author Ripan Malhi of the University of Illinois Urbana-Champaign in the US. “Our results inform on the ecology and diet of lions in the past as well as on the impacts of colonisation on life and land in this region of Africa.”
“Our analysis showed that the historic Tsavo lions preyed on giraffe, human, oryx, waterbuck, wildebeest, and zebra, and we also identified hairs that originated from lions,” adds first author Alida de Flamingh, also at Illinois. “This method can be used in many ways, and we hope other researchers will apply it to study prey DNA from other animal skulls and teeth.”
The Tsavo lions had dental injuries where prey hair had stuck.
It is even possible, the researchers say, that going back through the layers of accumulated hair can reveal how the lions’ diet changed as they aged.
The researchers pieced together fragments of degraded DNA to determine the 6 prey species. They even narrowed the giraffe sample to a subspecies of Masai giraffe from southeast Kenya.
Finding wildebeest hair was a surprise.
“It suggests that the Tsavo lions may have either travelled farther than previously believed, or that wildebeest were present in the Tsavo region during that time,” de Flamingh explains. “The closest grazing area for wildebeest was over 50 miles [80km] from where the lions were killed.”
The research may offer insight into human-lion interactions today, as well as holding promise for future studies on even older samples.
“This methodology can potentially be used on hairs from broken teeth of more ancient carnivores from hundreds to thousands of years ago,” Malhi says. “The method opens up a new avenue of inquiry into the past.”
