Giant panda to digest cellulose is ascribed to the microbes in its gut. Pandas are born with sterile intestines and require bacteria obtained from their mother's feces to digest vegetation. The giant panda is a "highly specialized" animal with "unique adaptations", and has lived in bamboo forests for millions of years. The average giant panda eats as much as 9 to 14 kg (20 to 30 lb) of bamboo shoots a day to compensate for the limited energy content of its diet. Ingestion of such a large quantity of material is possible because of the rapid passage of large amounts of indigestible
Giant panda diet. Anthropologist Russell Ciochon observed: "[much] like the vegetarian gorilla, the low body surface area to body volume [of the giant panda] is indicative of a lower metabolic rate. This lower metabolic rate and a more sedentary lifestyle allows the giant panda to subsist on nutrient poor resources such as bamboo." Similarly, the giant panda's round face is the result of powerful jaw muscles, which attach from the top of the head to the jaw. Large molars crush and grind fibrous plant material. The morphological characteristics of extinct relatives of the giant panda suggest that while the ancient giant panda