Pandas

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Pandas

The name “panda” applies to two different species: the familiar and well-loved giant panda (Ailuropoda melanoleuca ), and the lesser-known red panda (Ailurus fulgens ). Scientists originally thought the two species were closely related because of similarities in their behavior, diet, anatomy, and distribution. However, despite these shared characters of the pandas, researchers have now determined that the two species are not related as closely as was previously thought.

Giant Panda

Despite the popularity and familiarity of the giant panda to most people, and its status as an endangered species, much is still unknown about its biology and ecology. Researchers working in the Chinese A giant panda in China. (JLM Visuals.)

mountain-forest preserves where the remaining wild pandas live are hoping to correct this, and to increase the chances of saving the species from extinction.

Giant pandas are large, heavy-set animals with distinctive coloration: white fur with black or brownish black patches on their legs, shoulders, ears, and around the eyes. Fully grown giant pandas measure 4-5 ft (1.2-1.5 m) from nose to rump and weigh 156-350 lb (75-160 kg). The habitat of giant pandas is sub-alpine spruce-fir-bamboo forest in eastern China, at altitudes of 8,200-11,500 ft (2,500-3,500 m) above sea level. Adults are solitary, except females with offspring, and they den in tree holes, small caves, or crevices in rocky slopes. Although their diet consists largely of bamboo stems and leaves, pandas also eat other plant material (such as iris, crocus, vines, grasses, and tree bark), as well as some meat. To obtain sufficient nutrition from their fibrous foods, pandas spend 10-14 hours per day eating up to 80 lb (36 kg) of plant material, mostly bamboo.

Evolution and classification

Fossils of giant pandas dating as far back as the middle Pleistocene era (about 600,000 years ago) have been found in central and southern China. This suggests that the prehistoric range of giant pandas was much greater than at present, which is restricted to portions of north-central Sichuan Province and southern Gansu Province, and the Qinling Mountains of Shaanxi Province of China.

Giant pandas are descended from the same ancestral carnivores as bears, raccoons, dogs, and cats, and so are placed in the order Carnivora (carnivores) within the class Mammalia (mammals). Pandas have, however, almost entirely lost the meat-eating habit. Some scientists classify the giant panda in the bear family (Ursidae), while others place it in its own family (Ailuropodidae).

The first non-Chinese person to describe the giant panda was Pere Armand David, a French missionary living in China, in 1869. He called the panda a bear, based on its bear like appearance. The next year scientists in Europe examined skeletons and concluded that giant pandas resembled red pandas (which were classified within the raccoon family) more than they did bears. This element of panda classification is still being examined by biologists.

Many aspects of the panda’s skeletal structure and behavior support the idea that it is not a bear. An especially important piece of evidence is the presence of a special “sixth digit,” which acts in the manner of an opposable thumb. This digit is actually an extension of a bone in the wrist, and it allows giant pandas to grasp bamboo shoots and efficiently strip off their leaves. The red panda also has such a “thumb,” although it is less well-developed. Other aspects of panda biology which bears do not possess include: well-developed molar teeth and non-hibernation in winter.

Techniques in molecular biology have allowed scientists to create a “family tree” (or phylogenetic tree) of the relationships among bears, pandas, and raccoons. This has suggested that giant pandas are more closely related to bears than to raccoons, whereas red pandas are more closely related to raccoons.

Reproduction

Giant pandas are territorial throughout the year, with males and females maintaining separate feeding territories. During the breeding season (March to May in the wild), males increase their territory size to overlap the territories of several females, with whom they attempt to mate. Gestation is five months long, and one to two young are born (although only one is ever raised). The young are 3.2-4.6 oz (90-130 g) in weight and 5.9-6.6 in (15-17 cm) long at birth, and are blind and helpless. They are initially covered with sparse white fur, but the characteristic black patches appear within two weeks. At two months, the cub weighs 7-11 lb (3-5 kg), its eyes are open, and it has begun to crawl, although its hind limbs will not yet support it. At six months, the cub is weaned (meaning it has stopped suckling), but it does not leave its mother until she becomes pregnant again, about six months later.

After leaving their mother, young female pandas are thought to wander some distance to find a territory in a different area. This behavior reduces inbreeding in panda populations. Pandas become sexually mature at six to seven years of age, and probably live to about age 15 in the wild. The small number of young produced per female per year, plus the relatively late age of sexual maturity, means that population growth rates are low. This makes giant panda populations vulnerable to extinction if the rate of mortality increases.

Conservation and Captive Breeding

In 1984, the U.S. Fish and Wildlife Service listed the giant panda as an endangered species, restricting importation into the United States. The giant panda is also listed as endangered by the IUCN. International trade in giant pandas is controlled under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Official Chinese estimates place the total giant panda population in the wild at fewer than 1,600 individuals, most of which live in 13 forest reserves established for this rare animal in China. Recent DNA studies of panda feces, however, indicate that the population may be greater than estimated by as much as 50%, good news for the survival of the species. The two major threats to the survival of giant pandas are habitat loss and poaching.

The giant panda lives only in particular types of subalpine forest. Destruction of this habitat by deforestation is a serious problem, because giant pandas living there have no other place to go. It is estimated that suitable habitat was halved between 1980 and the late 1990s. The Chinese government is attempting to deal with this problem through a plan to relocate logging operations out of panda habitats, to create 14 new reserves, and to expand the size of existing reserves.

Although pandas are legally protected in China as an endangered species, poaching still occurs. Panda pelts can sell for more than $10,000 in Hong Kong, Taiwan, and Japan. The Chinese government has set sentences for convicted poachers of life imprisonment, or even death, and these stiff sentences may begin to deter the killing of wild pandas.

Pandas have been kept in western zoos since the 1930s, and in Chinese zoos since the 1950s. The first birth of a giant panda in captivity occurred at the Beijing Zoo in 1963, and other births have followed. The first captive birth outside China occurred in 1980 at the Mexico City Zoo. The Chinese government presented a pair of pandas to the National Zoo in Washington, D.C. in 1972. For 20 years, the pair attracted visitors from around the country, although they never succeeded in raising young. To date, captive births outside of China have been very few, although researchers in many countries are trying to develop successful breeding programs.

Red panda

Red pandas are medium-sized mammals with striking coloration. Their coat is colored reddish to dark chestnut on the back and darker on their legs and belly. They have a striped tail, white on the face and the front of the ears, and red or brown stripes from the outside corners of the eyes to the corners of the mouth. Adult red pandas are 20-24 in (50-60 cm) long, with a bushy 11-19 in (28-49 cm) tail, and weigh 7-10 lb (3-4.5 kg). They are native to Himalayan conifer-bamboo forest, at altitudes of 4,900-13,000 ft (1,500-4,000 m). Red pandas are nocturnal, foraging for food on the ground at night, and sleeping in trees during the day. Like giant pandas, red pandas eat mainly bamboo (although they eat only the leaves, not the stems), supplementing their diet with grasses, fruits, and small animals such as insects.

Red pandas are mainly solitary and territorial, with the territory of a male overlapping that of several females during the breeding season. One or two young are born in mid-May to mid-July after a three to five month gestation period. Females give birth in a tree-hole and raise the young alone. The young are weaned at five months, and become sexually mature at 18-20 months of age.

Like giant pandas, red pandas are classified in the order Carnivora. Within this order, the red pandas are usually placed in the raccoon family (Procyonidae). However, the IUCN places the red panda in its own family, the Ailuridae. This is partly because the red pandas are found only in the Old World, while members of the raccoon family occur in the New World.

KEY TERMS

Bamboo —Tropical grasses with tough woody stem from which leaves sprout.

Inbreeding —Breeding between closely related individuals, which is undesirable because of an increased probability of birth defects in the offspring.

Phylogenetic tree —A diagram showing the evolutionary relationships among groups of organisms.

Procyonidae —A family in the order Carnivora, including the coatis, kinkajou, olingos, raccoons, ringtails, and according to some biologists, the red panda.

Ursidae —A family in the order Carnivora, including all types of bears, and according to some biologists, the giant panda.

Red pandas are found over a much wider range than giant pandas, although this is still a relatively small area. They are found in the Himalayas, from Nepal to Sichuan and Tibet. At present some researchers estimate the Nepalese population size of red pandas to be only 300, although other workers argue that this estimate is too low. Population sizes in other areas of the range of the red panda are unknown, but are thought to be declining. The IUCN classifies the red panda as endangered.

Like giant pandas, red pandas are affected by habitat destruction and poaching. Deforestation removes not only their food supply, but also the trees in which they roost. Some red panda habitat is protected in the system of Chinese reserves designed for the giant panda. However, the situation in other parts of the red panda’s range is unclear. Red pandas are still hunted for their fur and, in places, for their meat. CITES has reduced the illegal trade in red pandas, although animal dealers may get around the convention by falsely stating that their animals originated in a captive-breeding program. Captive breeding of red pandas is relatively successful, with five programs worldwide.