A2 AASHIRWAD, II CROSS LANE, LOKHANDWALA COMPLEX, ANDHERI (WEST), MUMBAI 400053, INDIA

The mystery of what drove two lions to hunt down and eat more than 130 railway workers in Kenya in 1898 may now be solved: The beasts suffered from excruciating toothaches.

The lions, which stand stuffed at the Field Museum of Natural History and were immortalized in the 1996 film "The Ghost and Darkness," had dental problems so severe that they might have abandoned more difficult prey and turned to humans, according to research by a Field zoologist and a Waukegan dentist.

"Humans are easy prey. We're very slow, we don't hear very well, and we don't see very well in the dark," said Bruce Patterson, a zoologist at the museum.

Patterson is scheduled to present a paper Tuesday at the annual meeting of the American Society of Mammalogists on his research on the skulls of the two Tsavo (SAH-vo) lions and on a third man-eater acquired by the museum two years ago. The paper is co-authored by Ellis Neiburger, a practicing dentist whose expertise on carnivores is often called upon by zoologists and paleontologists.

Their findings coincide, Patterson said, with an "infirmity theory" that explains that wild lions and tigers sometimes hunt humans when they are slowed by infirmities and can't chase or kill animals they normally eat.

All three of the Field's man-eaters had severe dental and jaw problems, said Patterson. One of the Tsavo lions was in particularly bad shape, with a row of three missing teeth, a broken, probably painfully abscessed lower canine tooth, and an upper canine so loose and wobbly that it probably was useless.

Canine teeth in cats are critical to their "killing bites" that sever spinal cords of smaller prey and their "throttling grips" across the throats of large prey, suffocating them by closing the windpipe.

"It's clear from the condition of the one Tsavo lion that it was severely disabled and probably couldn't go after normal prey," said Patterson.

He cited work by a famed tiger hunter in India, Jim Corbett, who in the 1930s often was called in to track and shoot tigers that were killing villagers. Corbett came up with the strongest evidence of the "infirmity" theory of man-eaters, Patterson said.

"Time after time," Patterson said of Corbett, "when he examined his slain quarry, he found broken bones, old age or some other crippling infirmity."

Only the skulls and skins of the Field's three man-killers were preserved, so it is difficult to determine if they had other serious physical infirmities in their limbs or torsos.

"All three of them had pretty severe dental problems, with abscesses that might have been so painful that they could not bite down forcefully," said Neiburger. "That might have sent them looking for human prey."

For more than 100 years, game experts have puzzled over why the two "Lions of Tsavo " came to acquire a taste for humans. Lions normally avoid any kind of human contact, but the Tsavo lions became so proficient at terrorizing the camps of railway workers that all construction on a bridge over the Tsavo River stopped for several months.

The railway route followed the footpath that for hundreds of years had been a route used by slave caravans carrying trade goods from the African interior to the coast. Slaves died constantly along the route, and Neiburger said lions in the area may have become conditioned to looking upon humans as easy food.

Whatever whetted the appetites of the Tsavo lions for humans, working in tandem, the lions efficiently raided railway camps almost nightly, leaping into tents and dragging men away. The lions spooked both workers and hunters hired to kill them by avoiding and evading ambushes and traps.

"We call them dumb animals," said Neiburger, "but, holy smoke, humans were just like chicken at the Jewel for them."

The Tsavo lions continued to kill until the railroad's construction engineer, British Lt. Col. John Patterson, no relation to Bruce Patterson, finally managed to kill them himself.

He kept their skulls and used their skins as rugs in his home until selling them for $5,000 to the Field Museum in 1926. They became one of the museum's most popular exhibits after the Michael Douglas film came out four years ago.