Captive elephants die much younger than their wild counterparts, a new study reports. Researchers comparing pachyderms in European zoos and in the wild found that those in captivity had lifespans decades shorter and a greater number of stillbirths. Obesity, limited roaming space, and lack of companionship are thought to contribute to the early deaths. Says study leader Georgia Mason: “Currently zoos are consumers rather than producers of elephants…. We feel that’s not really appropriate” [The New York Times].
As reported in Science [subscription required], the researchers analyzed data on 4,500 African and Asian elephants, mostly female (zoos usually keep female elephants), kept in European zoos; they also looked at wild populations in Kenya and Myanmar. They found that African elephants in zoos had a median lifespan of 16.9 years compared to 56 years for elephants living in national park in Kenya. For Asian elephants, which are more endangered, the median lifespan for those in zoos was 18.9, compared to 41.7 years for those working on a timber enterprise in Myanmar but allowed to roam free. These numbers excluded premature and still-births, but researchers say still-births are also more common in zoo elephants.
One major contributing factor could be the high rate of obesity among zoo elephants, which are kept in enclosures much smaller than their natural habitats, suggests Mason. “The vast majority are overweight in zoos, this could explain the high still-birth rates and why they’re dying early. Bigger mothers have bigger calves and more of these are still-born,” she said. “If the zoo does not have space, its simple – don’t take elephants” [BBC News]. Elephants in zoos are also deprived of their natural social structures and experience more stress as a result. In the wild, most elephants live in large herds of related females with males interacting with these groups in various ways. Zoos tend to have just a few elephants in the same enclosure [LiveScience.com]. Broken relationships forced by transfers between zoos can be especially traumatic for the social and highly intelligent animals.
Zoo officials expressed outrage at the new findings, calling them grossly inaccurate. Paul Boyle of the Association of Zoos and Aquariums criticized the study for using data that extended back to 1960. “If you were looking at the success of heart transplants and you reached back 48 years, you would be obviously biasing the success rate,” he said [The New York Times]. He says conditions in zoos and knowledge of pachyderm nutrition and behavior have improved significantly in recent decades. Mason says they are not recommending that zoos abandon elephants…. But she said their findings suggested that imports of elephants should be limited to zoos that can identify and treat their problems, that transfers between zoos be minimized and that breeding efforts be limited to zoos with a record of success [The New York Times].
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Image: flickr / Ryan McCullah