An analysis of the microscopic wear on the teeth of the legendary â€œman-eating lions of Tsavoâ€ reveals that it wasnâ€™t desperation that drove them to terrorize a railroad camp in Kenya more than a century ago.
â€œOur results suggest that preying on people was not the lionsâ€™ last resort, rather, it was simply the easiest solution to a problem that they confronted,â€ said Larisa DeSantis, assistant professor of earth and environmental studies at Vanderbilt University.
The study, which she performed with Bruce Patterson, MacArthur Curator of Mammals at The Field Museum of Natural History in Chicago, is described in a paper titled â€œDietary behavior of man-eating lions as revealed by dental microwear texturesâ€ published online April 19 by the journal Nature: Scientific Reports. …
In order to shed light on the lionâ€™s motivations, DeSantis employed state-of-the-art dental microwear analysis on the teeth of three man-eating lions from the Field Museumâ€™s collection: the two Tsavo lions and a lion from Mfuwe, Zambia that consumed at least six people in 1991. The analysis can provide valuable information about the nature of animalâ€™s diet in the days and weeks before its death.
DeSantis and Patterson undertook the study to investigate the theory that prey shortages may have driven the lions to man eating. At the time, the Tsavo region was in the midst of a two-year drought and a rinderpest epidemic that had ravaged the local wildlife. If the lions were desperate for food and scavenging carcasses, the man-eating lions should have dental microwear similar to hyenas, which routinely chew and digest the bones of their prey.
â€œDespite contemporary reports of the sound of the lionâ€™s crunching on the bones of their victims at the edge of the camp, the Tsavo lionâ€™s teeth do not show wear patterns consistent with eating bones,â€ said DeSantis. â€œIn fact, the wear patterns on their teeth are strikingly similar to those of zoo lions that are typically provisioned with soft foods like beef and horsemeat.â€
The study provides new support for the proposition that dental disease and injury may play a determining role in turning individual lions into habitual man eaters. The Tsavo lion that did the most man eating, as established through chemical analysis of the lionsâ€™ bones and fur in a previous study, had severe dental disease. It had a root-tip abscess in one of its caninesâ€”a painful infection at the root of the tooth that would have made normal hunting impossible.
â€œLions normally use their jaws to grab prey like zebras and buffalos and suffocate them,â€ Patterson explained. â€œThis lion would have been challenged to subdue and kill large struggling prey. Humans are so much easier to catch.â€
The diseased lionâ€™s partner, on the other hand, had less pronounced injuries to its teeth and jawâ€”injuries that are fairly common in lions which are not man eaters. According to the same chemical analysis, it consumed a lot more zebras and buffalos, and far fewer people, than its hunting companion.