WASHINGTON -- Zoo elephants don't live as long as those in the wild, according to a study sure to stir debate about keeping the giant animals on display.
Researchers compared the life spans of elephants in European zoos with those living in Amboseli National Park in Kenya and others working on a timber enterprise in Myanmar. Animals in the wild or in natural working conditions had life spans twice that or more of their relatives in zoos.
Animal care activists have campaigned in recent years to discourage keeping elephants in zoos, largely because of the lack of space and small numbers of animals that can be kept in a group. Debates have been especially vocal in Dallas and Los Angeles.
The researchers found that the median life span for African elephants in European zoos was 16.9 years, compared with 56 years for elephants who died of natural causes in Kenya's Amboseli park. Adding in those elephants killed by people in Africa lowered the median life span there to 35.9 years. Median means half died younger than that age and half lived longer.
For the more endangered Asian elephants, the median life span in European zoos was 18.9 years, compared with 41.7 years for those working in the Myanmar Timber Enterprise. Myanmar is the country formerly known as Burma.
There is some good news, though. The life spans of zoo elephants have improved in recent years, suggesting an improvement in their care and raising, said one of the report's authors, Georgia J. Mason of the animal sciences department at the University of Guelph, Canada.
But, she added, "protecting elephants in Africa and Asia is far more successful than protecting them in Western zoos."
There are about 1,200 elephants in zoos, half in Europe, Mason said in an interview via e-mail. She said researchers concentrated on female elephants, which make up 80% of the zoo population.
"One of our more amazing results" was that Asian elephants born in zoos have shorter life spans than do Asian elephants brought to the zoos from the wild, she added in a broadcast interview provided by the journal Science, which published the results in its Friday edition.