One of Tsavo's lions ate mostly human prey

CHICAGO (Reuters) - Two man-eating lions terrorized Kenya during the building of a railroad bridge over the Tsavo River in the late 19th century, but only one was making regular meals of human prey, researchers said on Monday.

The lions attacked and devoured workers building the Ugandan Railway line through Kenya during several months in 1898, stalling construction and creating a legend that became fodder for the 1996 movie "The Ghost and the Darkness."

The man-eaters, whose skins are displayed at the Field Museum in Chicago, were finally slain a few weeks apart in December 1898 by British officer John Henry Patterson.

Patterson often claimed the predators had killed 135 people but that figure has been disputed. Other researchers at the Field Museum analyzed Patterson's journal and other accounts to arrive at a much lower range of probable victims.

In the latest research published in the Proceedings of the National Academy of Sciences, a researcher at the University of California, Santa Cruz, and one at the Field Museum analyzed the hair and teeth of the beasts to determine what they ate.

The research showed that the lions consumed as many as 72 victims, although there may have been considerably fewer.

"We don't seek to diminish the story at all. If anything we're adding an additional layer," said University of California ecologist Justin Yeakel, one of several researchers who worked on the study. "The lions had different diets."

One of the two large male lions was getting nearly one-third of its diet from human meat, while the other about half that much.

"It doesn't appear they were starving," said Yeakel.

Lions, which hunt in groups and alone, respect ownership of a kill when it comes to eating prey, he said.

The lion with the substantially human diet was known to be the main predator hunting humans and probably consumed the biggest share of his kills, with little left over for the other lion.

"Because we're not a big meal, that's why they had such different diets," Yeakel said.

Environmental changes in that part of Kenya had reduced the lions' usual prey -- mainly zebra and antelope in the grasslands. But injuries to the big cats' teeth and jaws may also have made hunting wild animals more difficult, leading them to turn their attention to the railway workers.

"Humans are dangerous animals to specialize on, if you're a lion. Lions know this," Yeakel said. "We live in groups, we have weapons, we're very efficient predators."

(Editing by Chris Wilson)