Appendix: Advantages of feeding on umbrella bamboo shoots

Umbrella bamboo shoots are much larger and have more girth than those of arrow bamboo. They are also higher in protein than arrow bamboo leaves, although the amino acid balance is not so good. From a panda’s point of view it makes good sense to feed on umbrella bamboo: it is far more rewarding, in terms of energy, to eat thick juicy shoots than thin juicy shoots. With both, energy must be expended to search for, pick and process the shoots. The umbrella bamboo shoot obviously provides a far higher ratio of energy input to energy output than its less robust relative. This is true is shown by the animal’s behavior within such a stand.