Courtesy of Born Free Foundation/Chris Draper
An Asian elephant in a European zoo.
An Asian elephant in a European zoo. Courtesy of Born Free Foundation/Chris Draper
Courtesy of C. Moss, ATE
An adult female elephant, her adult daughter and their calves in a natural, free-range population.
An adult female elephant, her adult daughter and their calves in a natural, free-range population. Courtesy of C. Moss, ATE
Living in a zoo shortens an elephant's life, according to a new research study published in the journal Science.
The study compared the life spans of African and Asian elephants living in European zoos between 1960 and 2005, with the life spans of African elephants living in the Amboseli National Park in Kenya and Asian elephants living in a reserve in Myanmar.
"We looked at about 300 African female elephants [in zoos], and of those, none have made it past the age of 50," says study author Georgia Mason of the University of Guelph in Canada. "In Amboseli National Park, about a third of the females will make it past age 50."
The results for Asian elephants were less promising. According to Mason, half the animals living in Myanmar had died by age 41, whereas in European zoos, half of all elephants die by the age of 19.
"Quite a dramatic difference," says Mason.
Critics point out that the two wild populations Mason studied have special protections, and that elephants outside of these areas face threats to their survival as a species, including poaching and loss of habitat. It's estimated there are only about 30,000 Asian elephants in the wild today, compared with an estimated 200,000 a quarter-century ago. The number of African elephants is also declining, although less drastically.
Paul Boyle, senior vice president for conservation and education at the Association of Zoos and Aquariums, takes issue with Mason's numbers. Research done by one of his member zoos showed that "the average life expectancy for Asian elephants in [U.S. zoos] is 44.8 years, and the average life expectancy for Asian elephants in the wild is 45 years," says Boyle. "Statistically, 44.8 and 45 are the same number."
In addition, he says that by including data going back as far as 1960, Mason has ignored improvements in animal management, including better diets and better medical care.
"So there's a significant bias in this paper to include data back at a time when nobody was as good at keeping animals healthy and alive as our institutions are today," Boyle says.
Mason says she and her colleagues looked for indications that things were getting better for elephants over time. She says she found improvements for African elephants, but not Asian elephants.
Zoos need to do a better job of figuring out what elephants in captivity need to live a long and healthy life, she says.
"It's clear that some animals are living decent, long lives," says Mason. "And other animals are dying really early. And I think it's now really important to work out why some zoos are successful and others aren't.