Obesity has become one of the biggest problems facing zoo elephants today -- and threatening their ability to reproduce. About 40 percent -- nearly half -- of African elephants in captivity are affected by obesity.
"Much as we see in humans, excess fat in elephants contributes to the development of heart disease, arthritis, a shorter lifespan and infertility," Daniella Chusyd, M.A., a doctoral student in the University of Alabama at Birmingham Department of Nutrition Science who recently launched a study to examine the problem, told Phys.org.
Even worse, a high body mass index in elephants is strongly correlated with abnormal ovarian cycles, which means that the U.S. zoo population could face a challenge in the coming decades. In order to keep its population stable, zoo elephants in the U.S. must produce about six calves each year -- but the current average is only around three births a year. One scientist suggested that at the current rate, "the African elephant could be gone from U.S. zoos within 50 years."