Fecal Specimen (IMAGE) University of Wisconsin-Madison Caption This is a fecal sample from a giant panda, showing a mix of bamboo stalk and leaves. Bamboo is tough and fibrous and panda digestive systems are not well-designed to break down this material, though it is the primary source of nutrition in their diet. Pandas eat up to a third of their body weight in bamboo every day. Credit Candace Williams Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.