It’s not often that the lede in a science story is attributed to Hollywood movies, but in this case Ewen Callaway of New Scientist does precisely that.

Callaway’s lede: “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.”

He’s reporting a study in PNAS in which Justin Yeakel of the University of California, Santa Cruz, used bone and hair samples from the man-eating lions of Tsavo to determine that they ate about 35 people. But one had more of a taste for humans than the other, devouring 24, while his more discerning partner ate a mere 11. They didn’t eat 135.

Yeakel figured that out, Callaway reports, by “comparing the isotopic ratios of nitrogen and carbon in the lions’ remains with that of contemporary lions, humans, and herbivore prey.” Callaway doesn’t explain how Yeakel did that, and I’m having trouble guessing.

This is a local story for Kim Janssen of the Chicago Tribune, who seems a little sorry to deflate the Hollywood account: “For more than 80 years, the man-eating Tsavo lions have been one of the [Chicago] Field Museum’s top tourist draws,” Janssen writes. “Now a study released Monday suggests the Tsavo lions’ taste for human flesh may have been exaggerated.” (According to the Trib, this is a photo of the stuffed human-eaters.)

Janssen doesn’t help me with the isotope business; she adds that the comparisons were made between the human prey and the lions’ usual prey of zebra, wildebeest, and buffalo. But I’m still guessing how that leads to a number as precise as 35.

The news section in Nature solved my problem. Lizzie Buchen explains the isotope business. (See her story for more.) She also quotes another researcher not involved with the research who is skeptical of the findings. That sort of informal peer review should be done in just about every science story, as I used to tell my AP colleagues when I worked there. (I’ve complained before about Nature’s silly policy of charging exorbitant fees for copies of news articles, but I’m including this story because it appears to be freely available.)

NPR files a short blog post on this story, quoting at length from the Trib story. Did NPR have permission? Why bother with this instead of running with the AP, or (better) doing its own story? What gives? The blog is called “The Two-Way,” but this looks to me like a one-way expropriation.

Randolph E. Schmid of the AP, by way of the San Francisco Chronicle website: “The nightly attacks by two man-eating lions terrified railway workers and brought construction to a halt in one of east Africa’s most notorious onslaughts more than a hundred years ago. But the death toll, scientists now say, wasn’t as high as previously thought.”

Grist for the Mill: UC Santa Cruz press release.

- Paul Raeburn

This entry was posted on Monday, November 2nd, 2009 at 3:25 pm and is filed under Science Stories. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.