Giant Panda Hu Bao eats bamboo at Bifengxia base in Ya'an, Sichuan province, in this file photo taken September 3, 2012. Researchers have found that the giant panda is downright miserly in the amount of energy it expends on a daily basis – a level similar to that of the famously sluggish three-toed sloth – thanks to low levels of physical activity and low levels of thyroid hormones. (Photo by Reuters/China Daily)
