Giant panda

Today, the giant panda (Ailuropoda melanoleuca ) is one of the best known and most popular large mammals among the general public. Although its existence was known long ago, having been mentioned in a 2,500-year-old Chinese geography text, Europeans did not learn of its existence until its discovery by a French missionary in 1869. The first living giant panda did not reach the Western Hemisphere until 1937. The giant panda, variously classified with the true bears or, often, in a family of its own, once ranged throughout much of China and Burma, but is now restricted to a series of 13 wildlife reserves totaling just over 2,200 mi² (5,700 km²) in three central and western Chinese provinces. The giant panda population has been decimated over the past 2,000 years by hunting and habitat destruction. In the years since 1987, they have lost more than 30% of their habitat. Giant pandas are one of the rarest mammals in the world, with current estimates of their population size at about 1,000 individuals (150 in captivity). Today human pressure on giant panda populations has diminished, although poaching continues. Giant pandas are protected by tradition and sentiment, as well as by law in the Chinese mountain forest reserves. Despite this progress, however, IUCN—The World Conservation Union—and the U. S. Fish and Wildlife Service consider the giant panda to be endangered. Some of this species' unique requirements and habits do seem to put them in jeopardy.

The anatomy of the giant panda indicates that it is a carnivore, however, its diet consists almost entirely of bamboo, whose cellulose cannot be digested by the panda. Since the giant panda obtains so little nutrient value from the bamboo, it must eat enormous quantities of the plant each day, about 35 lb (16 kg) of leaves and stems, in order to satisfy its energy requirements. Whenever possible, it feeds solely on the young succulent shoots of bamboo, which, being mostly water, requires it to eat almost 90 lb (41 kg) per day. This translates into 10–12 hours per day that pandas spend eating. Giant pandas have been known to supplement their diet with other plants such as horsetail and pine bark, and they will even eat small animals, such as rodents, if they can catch them, but well over 95% of their diet consists of the bamboo plant.

Bamboo normally grows by sprouting new shoots from underground rootstocks. At intervals from 40 to 100 years, the bamboo plants blossom, produce seeds, then die. New bamboo then grows from the seed. In some regions it may take up to six years for new plants to grow from seed and produce enough food for the giant panda. Undoubtedly this has produced large shifts in panda population size over the centuries. Within the last quarter century, two bamboo flowerings have caused the starvation of nearly 200 giant pandas, a significant portion of the current population. Although the wildlife reserves contain sufficient bamboo, much of the vast bamboo forests of the past have been destroyed for agriculture, leaving no alternative areas to move to should bamboo blossoming occur in their current range.

Low fecundity and limited success in captive breeding programs in zoos does not bode well for replenishing any significant losses in the wild population. Although there are 150 pandas in captivity, only about 28% are breeding. In 1999, the first giant panda to live more than a few days was born in captivity. For the time being, the giant panda population appears stable, a positive sign for one of the world's scarcest and most popular animals.

[Eugene C. Beckham ]

RESOURCES

BOOKS

Nowak, R. M., ed. Walker's Mammals of the World. 5th ed. Baltimore: Johns Hopkins University Press, 1991.

PERIODICALS

"China goes High Tech to Help Panda Population." USA Today, August 13, 2001.

Drew, L. "Are We Loving the Panda to Death?" National Wildlife 27 (1989): 14–17.

"Pandas Still under Threat of Extinction." USA Today, February 16, 2001.