Was bad dentistry to blame for Tsavo man-eating lions’ 1898 killing spree?

Colonel Patterson with Tsavo Lion
The first of the two Tsavo man-eating lions ("The Ghost", FMNH 23970) shot by Lt. Col. Patterson.

While the man-eating lions of Tsavo were not the deadliest of the of all the threats facing the workers building the Lunatic Express, the British Empire’s railway from Uganda to the Indian Ocean, they were no doubt the most terrifying.

Over a period of nine months in 1898, the pair of maneless lions nicknamed The Ghost and the Darkness, appeared like spectres out of the Kenyan night skilfully avoiding traps, absorbing bullets with no visible effect, and killing and eating around 35 people, before they were finally killed by Lieutenant-Colonel John Henry Patterson.

Second Tsavo lion
The second man-eater from Tsavo, The Darkness, shot by Lieutenant-Colonel Patterson,now known as FMNH 23969.

To this day, naturalists have failed to agree on what drove the lions’ to their man-eating spree.

Some claim it was due to the outbreak of rinderpest (cattle plague) in 1898 which devastated the lions’ usual prey, forcing them to find alternative food sources. Another theory is that the Tsavo lions became accustomed to finding dead humans at the Tsavo River crossing which was routinely used by slave caravans bound for Zanzibar. Some have speculated that it was “Ritual invitation”, or abbreviated cremation of Hindu railroad workers, which invited scavenging by the lions.

However, an alternative argument put forward by Bruce Patterson, curator of mammals at the Field Museum in Chicago, which holds the lions’ stuffed remains, postulates that the first lion had a severely damaged tooth that would have compromised its ability to kill natural prey.

Tsavo Man-Eating lions
The Tsavo man-eating lions on display in the Field Museum of Natural History in Chicago, Illinois.Photo: Jeffrey Jung (used under the Creative Commons licence)

Dr Patterson and his colleagues claim the animals were driven to dine on the Indian workers by tooth abscesses that would have made biting through the tough hides of zebra and wildebeest too painful.

He developed his bad dentistry theory after analysing microscopic patterns of wear on the lions’ teeth. His findings, published in Scientific Reports, has been generally disregarded by the general public. andColonel Patterson himself (no relation to Dr Patterson) who says he damaged that tooth with his rifle while the lion charged him one night, prompting it to flee.

The Lunatic Express

Taking 30 years to complete and costing almost 2,500 lives, the Lunatic Express was loved by Winston Churchill who described it as “The British art of muddling through is here seen in one of its finest expositions,” in My African Journey.

It took Lieutenant-Colonel John Henry Patterson, who led the construction of the rail bridge over the Tsavo river in Kenya, four rifles and several months to finally kill the lions.

His published account of the struggle, The Man-Eaters of Tsavo (1907), has been dramatised in various movies including Bwana Devil (1952), Prey (2007), Mrugaraju (2001) and The Ghost and the Darkness (1996), which starred Michael Douglas and Val Kilmer.

The lions’ skins spent the next 25 years on the soldier’s floor before being sold for $5,000 to the museum in 1924.

An 2009 analysis by Dr Patterson in 2009 found that the first man-easter, The Ghost, which was 3m long and 1.14m tall, had eaten about 24 people. The other lion, The Darkness, which was 2.9m long and 1.19m high had eaten 10 or 11 victims.