The giant panda weighs 75 - 160 kg (165 - 353 lb). It occupies montane forests with dense stands of bamboo at altitudes of 2700 - 3900 m (8850 - 12,800') (although it may descend to as low as 800 m (2600') during winter). Cubs are born singly or in pairs, but the mother usually only raises one. The giant panda does not make a permanent den but takes shelter in hollow trees, rock crevices and caves. It is predominantly terrestrial but can climb trees well. Activity is largely crepuscular and nocturnal. It spends 10 - 12 hours a day feeding.
The giant panda does not hibernate but descends to lower elevations in the winter. The giant panda's diet consists mainly of bamboo shoots, up to 13 mm (1/2") in diameter, and bamboo roots. It also eats bulbs of plants such as iris and crocus, grasses and occasionally fish, insects and small rodents. Giant pandas are usually solitary, except during the mating season.
Giant panda populations have been declining for thousands of years due to hunting by humans and climatic changes. In ancient China it was already considered rare. It occurs in China's Gansu, Shaanxi and Sichuan (Kansu, Shensi and Szechwan) Provinces. Chinese research on the panda has revealed that reproduction in the wild is adequate and that the giant panda population has remained stable for 20 years.
Habitat loss is a major problem, with logging in panda habitat outside reserves now being the major threat. Other threats to the giant panda include poaching for its pelt; accidental death due to poaching for musk deer; and starvation due to the fragmentation of habitat, which causes pandas to be unable to reach alternative food sources when bamboo experiences its natural die-off.