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Giant Panda Diet |
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| Giant pandas are a study in the evolutionary process. Their most recent ancestor was a bearlike creature. Like other bears, giant pandas are technically carnivores - members of the order Carnivora. But, in fact, most bears are omnivores - they will eat almost anything, including meat, fruit, seeds and insects. But at one stage in their evolutionary history, giant pandas abandoned omnivory in favor of strict herbivory - eating green vegetation. Indeed, going a step farther than most herbivores, giant pandas even limited themselves to a single sort of grass - bamboo.
Their adaptations for feeding on bamboo make them morphologically unique. Giant pandas possess huge molar teeth and powerful masticatory muscles for breaking the woody portion of bamboo and chewing the stem, culms, and leaves. In addition, their forepaws are equipped with a sixth "digit" that acts as a thumb for holding bamboo. This "thumb" is derived from the radial sesamoid bone of the wrist. Surprising as it may seem to observers of giant pandas in the Zoo, black-and-white coloring probably acts as camouflage in the wild. In patches of dense bamboo, an immobile giant panda is nearly invisible, and virtually disappears among snow covered rocky outcrops on a mountain slope. The combined effect of foreshortened snout, round face, black eye rings, small rounded black ears, short squat tail, and distinctive body shape and markings gives the giant panda its characteristic infantile appearance, which is further enhanced by its habit of sitting upright, holding objects in its flexible forepaws, and walking pigeon-toed. For most of the year, individual giant pandas use fairly small home ranges: In good habitat they can find all the bamboo they need without moving very far. Males and females roam over areas varying in size from about one to 10 square miles, with little difference between the sexes. Some females studied by George Schaller in Wolong even occupied home ranges as small as 75 to 100 acres - less than the size of the Zoo. Seasonal as well as long-term changes in the availability of preferred foods, and the location of potential mates, sometimes results in pandas taking very long hikes outside of their normal territory. But more often they migrate vertically, up and down the mountainside, to find a preferred bamboo species or preferred parts of bamboos. Giant pandas normally exist at altitudes of 3,600 to 10,500 feet, depending upon prevailing local conditions; for example, in Wolong Reserve, the giant pandas occupy habitat from 7,550 to 10,500 feet, while in Shaanxi??s Foping Nature Reserve, the giant pandas remain at 3,600 to 9,500 feet. |