African Elephants in U.S. Zoos becoming Obese: Researchers

African elephants in captivity are getting fat. Obesity in elephants could be a threat to the survival of the species, researchers say.

Researchers at the University of Alabama at Birmingham said that obesity in elephants is no laughing matter.

"Obesity affects about 40 percent of African elephants in captivity," said Daniella Chusyd, M.A., a doctoral student in the University of Alabama at Birmingham Department of Nutrition Sciences, according to a news release. "Much as we see in humans, excess fat in elephants contributes to the development of heart disease, arthritis, a shorter lifespan and infertility."

Infertility is a major problem affecting African elephants in captivity. Estimates suggest that zoos in the United States need about six births per year to maintain a stable elephant population. However, the current average is just three births a year.

Daniella Chusyd and colleagues have now begun a new study to explore the relation between obesity and infertility in elephants. The team will be looking at the body composition and inflammation in these animals to understand what is driving obesity in elephants.

Researchers plan to use an objective method to gauge obesity in elephants. In their study, they will be using stable isotope called deuterium to measure total body water. They will also be comparing the amount of lean tissue in the body to the amount of fat tissue.

Currently, the only way zoologists can tell if a particular elephant is fat or not is by looking at the animal. "It's difficult to gauge obesity in an animal as large as an elephant," said Nagy. "The gold standard is a body condition score based on visual assessment, which is very subjective. This study will give us a much more reliable measure to determine which of these animals are obese."

The study, which will include female African elephants from U.S. zoos, is funded by the Eppley Foundation for Research.