An elephant's butt can tell you a lot about its health

Newsflash: Elephants are big. And they're getting bigger. Rose Eveleth at Smithsonian's "Smart News" writes:

Elephants in zoos are facing health problems that aren't so different from humans'. Like us, elephants are becoming obese, a condition associated with cardiac disease, arthritis, infertility and all sorts of other problems. Forty-five percent of elephants in zoos right now are infertile, and the biggest killer of zoo elephants is heart disease. If we don't do anything about it, the elephants we see in zoos will all be dead in 50 years.

Aside from being increasingly fatter, elephants can also be uncooperative, and even dangerous. They're not animals you can just take to the vet's office on a leash and give a checkup to. So how do assess their health easily? Look at their butts!

So [Kari] Morfeld [a researcher at the Wildlife Conservation Research Center] developed a system that used butt shots from elephants to give them a relative health score. She looks at indications like the visibility of the rib cage and the depth of fat along the pelvic bone and back bone...

On her score sheet, skinny elephants get 1′s and fat elephants get 5′s. In the wild, most elephants come in around 2, but in zoos, 40 percent of elephants are 5′s.

Elephants gain weight for the same reasons humans do—diet and lack of exercise. In the wild, elephants eat a whole wide range of foods from grass to tree leaves to bamboo to bark. But in captivity they eat quite differently, with fruits and grains and high-quality hay full of calories. Morfeld suggests switching to less calorie-rich hay as a first step. [Smart News]