The zoo world is in uproar over claims that captive elephants have far shorter lives than their free-roaming cousins.

Researchers writing in Science blame stress and obesity for the problem, which is most apparent in Asian elephants. Using data on 4,500 of the lumbering beasts, Georgia Mason, of the University of Guelph in Canada, and colleagues estimate that animals in European zoos have half the lifespan of protected populations in the wild.

“These kinds of questions often generate more heat than light, and our research shows what can be found out by analysing objective data,” says Mason (press release). “We hope it provides a model for tackling similar issues with other species.”

There’s certainly some heat coming her way this morning. Paul Boyle, of the US Association of Zoos and Aquariums, told the NY Times the paper was “terribly flawed” and contained “flagrant” errors.

Boyle takes particular issue with the claim that infant mortality rates for Asian elephants are far higher in zoos and have not improved over time. The researchers used data going back to the 1960s and Miranda Stevenson, of the British and Irish Association of Zoos and Aquariums, says in the Daily Mail, “Every year we have more young being born and surviving in European zoos, but we need to learn from past mistakes.”

Boyle also says the article doesn’t necessarily mean much for US zoos, including the controversial plan for LA’s zoo to breed Asian elephants.

“This is about elephants in Europe,” he says (LA Times). “There are wonderful zoos in Europe and there are zoos that are not so wonderful.”

Image: Born Free Foundation / Chris Draper

Graph: Survivorship curves for female African (A and B) and Asian (C and D) elephants aged 1 to 10 [juveniles in (A) and (C)] and 10+ years [adults in (B) and (D)] / Science.