Whats for supper? The Man-Eating Lions of Tsavo as depicted at the Field Museum of Natural History (Image: Field Museum of Natural History)

When the food gets scarce, it’s every lion for itself.

In 1898, according to numerous accounts and no fewer than three Hollywood movies, two male lions went on a nine-month killing spree around the Tsavo area of Kenya, devouring between 28 and 135 workers building the Kenya-Uganda railway.

Now an analysis of bone and hair samples from the notorious duo has backed the theory that scarcity drives dietary specialisation, and shows that food preferences can diverge within cooperating groups.


By comparing the isotopic ratios of nitrogen and carbon in the lions’ remains with that of contemporary lions, humans and herbivore prey, Justin Yeakel of the University of California, Santa Cruz, estimates the lions ate around 35 people.

The study also made a surprise finding. “One lion was consuming a lot of humans, and one was not,” Yeakel says. He attributes 24 deaths to one cat, or 30 per cent of its diet, and 11 deaths to the other, just 13 per cent of its food.

By the late 19th century, elephants in the area had been hunted away, causing grasslands to become overgrown woodlands and the number of ungulate prey to decline.

Most lions probably left the region, but two turned man-eaters, Yeakel speculates. “People are a dangerous food to go after,” he says. “One lion was able to figure out how to do it and wasn’t afraid, the other was not.”

Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0905309106