Giant Panda - biology.

Giant Panda - biology. I INTRODUCTION Giant Panda, bamboo-eating bear that lives in forests high in the mountains of central China. As one of the rarest but most recognized animals in the world, the giant panda has become an international emblem of endangered species and wildlife conservation efforts. The Chinese name for the giant panda, da xiong mao, means "great bear-cat." II PHYSICAL DESCRIPTION The giant panda resembles other bears in general appearance, with the exception of its coloring. The giant panda is white with black patches over its eyes, ears, and legs and a black band across its shoulders. Like other bears, the giant panda has long, shaggy fur. It keeps the giant panda warm in the cold and damp forest. Giant pandas have an enlarged wrist bone on the forefoot that functions as an opposable thumb. Their premolar teeth and molars are generally larger and broader than those of other bears, and their jaw bones and cheek muscles are exceptionally strong. These adaptations assist giant pandas in holding, crushing, and eating bamboo. An adult giant panda usually weighs between 75 and 160 kg (between 165 and 350 lb). Males are generally 20 percent heavier than females. The giant panda grows to about 1.5 m (about 5 ft) in head-and-body length, plus a 12.5-cm (5-in) tail. III HABITAT AND BEHAVIOR Giant pandas are found in the wild in the Sichuan, Gansu, and Shaanxi provinces of central China. They live in a few rugged mountain ranges at the eastern edge of the Tibetan Plateau where temperate broadleaf and coniferous forests contain dense stands of bamboo. Giant pandas are usually found at elevations between 2,300 and 3,800 m (7,500 and 12,500 ft) but will relocate to lower elevations in winter and spring. However, the zone of bamboo vegetation below 1,200 m (3,800 ft) has been cleared for agriculture in many areas, greatly restricting the giant panda's range. Unlike other bears that live in temperate climates, giant pandas do not hibernate. Bamboo is usually abundant and green even in winter, so they generally have no lack of food. Although giant pandas eat bamboo, they have the digestive system of a carnivore like other bears. Their system cannot efficiently digest bamboo, so they must eat large amounts to obtain enough nutrition. A giant panda must consume between 12 and 38 kg (26 and 84 lb) of bamboo each day. It spends 10 to 16 hours a day foraging and eating. A giant panda usually feeds in a sitting position, enabling it to grasp a bamboo stalk between its "thumb" and first two digits. It strips away the bamboo's tough outer layer with its teeth, and then slowly eats the peeled stalk. It also eats bamboo leaves, shoots, and roots. If its usual food supply is unavailable, a giant panda may feed on other plants, such as irises and crocuses, or even small animals, such as rodents. When not eating, a giant panda spends most of its time sleeping and resting. Giant pandas seem to have no permanent den, although they find shelter and give birth in caves or hollow trees. Giant pandas are fairly solitary most of the year. Small groups of giant pandas share a large territory and sometimes meet outside the breeding season. Both males and females may have overlapping ranges, and males show no evidence of territorial behavior other than scent-marking their routes. Giant pandas make a variety of sounds to communicate with each other, including bleats, honks, barks, growls, moans, and squeals. However, they never roar like some other bears. Mating takes place from March to May, and the young are born during August or September. A newborn cub usually weighs only 90 to 130 g (3 to 5 oz) and is about the size of a stick of butter. Born nearly hairless and unable to open its eyes for 40 to 60 days, the cub is completely defenseless and dependent on its mother. A giant panda mother will cradle her tiny cub in one paw and hold it close to her chest, nursing it often. Nearly half of giant panda pregnancies produce twins, but only one cub usually survives in the wild because the mother will neglect the other one. In captive breeding centers, human caretakers will switch the cubs so each receives enough milk from the mother to survive. A giant panda cub begins to walk when it is three to four months old. It starts eating bamboo around the fifth month of its life but will not be fully weaned from its mother's milk until the eighth or ninth month. Giant panda cubs may stay with their mothers for up to three years before striking out on their own. In the wild, a female giant panda will usually have a cub every other year for about 15 years of her life. However, many panda cubs do not survive to adulthood, and losses of young hinder the recovery of giant panda populations. Giant pandas generally live to between 20 and 35 years of age in captivity, and it is believed their lifespan is longer in the wild. IV CONSERVATION STATUS The World Conservation Union (IUCN) lists the giant panda as an endangered species. The giant panda is officially protected in China. An estimated 1,600 giant pandas live in the wild, about 60 percent of them in protected forests. More than 160 pandas live in captive settings such as zoos and breeding centers, mostly in China. Because giant pandas are restricted to a small area of China, their status may be the most precarious of all the species of bears. World interest and research funds from many nations have improved the giant panda's prospects, but the species remains vulnerable. Habitat destruction ranks as the greatest threat to the giant panda's survival. Giant pandas have lost most of their original habitat to an expanding human population. Giant pandas were once widespread in southern and eastern China. Due to human settlement and development, giant pandas have been pushed to the edge of their former distribution. They are now confined to small isolated patches of forest on six mountain ranges in central China. So many bamboo forests have been cleared at lower elevations that often only one species of bamboo survives on any given mountain. This lack of diversity in bamboo forests represents a threat to giant panda populations. In certain areas, giant pandas have died of starvation due to shortages of edible bamboo. The shortages occurred after entire bamboo forests flowered and set their seed. In the life cycle of bamboo, a mass flowering may happen at intervals of 1 to 100 years. The interval depends on the bamboo species, and only plants of the same species will flower at the same time. The mature plants die shortly afterward. It can take years for the bamboo sprouts, which grow from the seeds, to become tall enough to sustain a population of giant pandas. Before so many bamboo forests were cleared, giant pandas had been able to move up and down the mountainsides to find different types of bamboo to eat. Poaching (illegal hunting) continues to be a threat to giant pandas, despite severe penalties. Giant pandas are also injured or killed in illegal traps and snares set for other animals, such as musk deer and other kinds of bears. In 2007 conservationists announced that a parasitic roundworm was responsible for a significant number of the panda deaths reported in the wild since 1990. The parasite Baylisascaris schroederi causes the disease visceral larval migrans, which results in bleeding in the lungs, the liver, and the intestines, and can also affect the brain. It is not known if other recent pandas deaths were caused by the same parasite or by a different contagious disease. Loss of habitat from deforestation is forcing pandas to live closer together, likely making the animals more vulnerable to the spread of disease. V CONSERVATION EFFORTS The government of China has created more than 50 giant panda reserves, protecting more than 45 percent of the animal's remaining habitat. The first and largest of these, the Wolong Panda Reserve in Sichuan Province, was established in 1963. This and six other reserves in the province are now part of the Sichuan Giant Panda Sanctuaries, established as a World Heritage Site in 2006. Covering more than 9,000 sq km (3,475 sq mi), the mountain sanctuary is home to about a third of the world's wild giant panda population. The World Heritage Site designation qualifies the area for additional international aid in managing and protecting the giant panda populations there. Overall, nature reserves cover more than 16,000 sq km (more than 6,000 sq mi) of forest in and around the giant panda's habitat. However, studies indicate this is not enough to sustain wild giant panda populations in the long term. The giant panda's habitat is still fragmented, and the surviving populations are small and isolated from each other. Conservationists hope to establish protected forest corridors linking these isolated populations, in part to help reduce the incidence of inbreeding. A Research on Giant Pandas In 1980 the World Wildlife Fund (WWF) became the first international organization to work in China at the Chinese government's invitation. The WWF led the first-ever field studies and population surveys of the giant panda. It also helped establish the China Conservation and Research Center for the Giant Panda, based in the Wolong Panda Reserve. The WWF adopted the giant panda as its symbol, and the animal became an emblem of wildlife conservation efforts. Detailed information on wild giant panda populations remains scarce, largely due to difficulties in studying and monitoring them in their remote, rugged habitat. The WWF and other international organizations have collaborated with Chinese scientists on comprehensive field studies to learn more about the giant panda's ecology and behavior. In recent years more is being learned about the elusive animal and its habitat thanks to more high-tech surveying techniques, such as satellite imagery. Scientists long debated whether giant pandas are more closely related to raccoons or bears. In the 1980s molecular analyses comparing the proteins and genetic material (DNA) of giant pandas with those of bears and members of the raccoon family fully corroborated the substantial anatomical and fossil evidence classifying the giant panda as a member of the bear family. DNA analysis suggests the ancestors of the giant panda branched off from the main bear lineage about 15 million to 18 million years ago. This knowledge has helped scientists develop more effective conservation programs specifically suited to bears. Research is carried out in zoos and breeding centers around the world. Several zoos in the United States contain giant pandas, including the National Zoo in Washington, D.C., and the San Diego Zoo in California. These zoos host giant pandas on ten-year loans from China. In 1998 the U.S. Fish and Wildlife Service instituted a policy requiring U.S. zoos to partner with China in conservation efforts in order to host giant pandas. Zoos must contribute funds for habitat conservation in China, as well as designing research and breeding programs to benefit giant pandas. B Breeding Programs Increasing the number of giant pandas in captivity through breeding programs is another important conservation goal. The zoo population represents an insurance policy against the threat of giant pandas going extinct in the wild. The first giant panda to be born in captivity was at the Beijing Zoo in 1963. That zoo also produced the first giant panda birth resulting from artificial insemination in 1978. However, for many years giant pandas were notoriously difficult to breed in captivity. Newborn cubs suffered high mortality rates, with few surviving the first month. More recently, intensive and collaborative research on the giant panda has increased the success of breeding programs. Improvements have included providing giant pandas in captivity with a more natural, forest-like environment and an enriched diet. Scientists also improved the formula used to feed newborn cubs, thereby boosting their immune systems. Weak immune systems make young cubs more likely to die of diseases. The Wolong Giant Panda Research Center, the world's leading facility for captive-breeding efforts, reported unprecedented success in 2005. That year, 11 female giant pandas at the Wolong center gave birth to 16 cubs, all of which survived. The new mothers at the center included Hua-mei, a giant panda born in 1999 at the San Diego Zoo. Hua-mei was noteworthy in her own right as the first giant panda born in North America to survive to adulthood. VI GIANT PANDA HISTORY Fossil evidence suggests that giant pandas were already widespread in what is now southern and eastern China about 2 million to 3 million years ago, during the Pliocene epoch. Giant panda fossils have also been found in northern Myanmar and northern Vietnam. References to the giant panda are found in ancient Chinese texts. The Classics of Seas and Mountains, a 2,500-year-old geography book, refers to "a bear-like, blackand-white animal that...lives in the Qionglai Mountains south of Yandao County." This book refers to the giant panda as mo, an ancient name for the species. The Western world first became aware of the giant panda in 1869, when the French missionary and naturalist Père Armand David reported his observations of a dead hunted specimen. In 1916 German zoologist Hugo Weigold became the first Westerner to see a live giant panda in the wild. In 1936 American socialite Ruth Harkness brought a female cub named Su-lin to the United States. The first giant panda to reach the country alive, Su-lin was exhibited in the Brookfield Zoo in Chicago, gaining worldwide attention and adulation during her short life. Other giant pandas brought to U.S. zoos in the years after Su-lin also died early due to lack of knowledge about how to properly care for them. In the 1950s the Communist government of China began giving giant pandas as goodwill gifts to other countries, a practice that became known as "panda diplomacy." For example, China sent two giant pandas to the United States in 1972 following a visit to China by President Richard Nixon. China currently loans pandas for exhibit in zoos around the world in a program that requires cooperative research and funding for conservation in exchange. Scientific classification: The giant panda was formerly classified as a member of the raccoon family, but is now considered a true bear. The giant panda belongs to the subfamily Ailuropodinae in the family Ursidae, order Carnivora. It is classified as Ailuropoda melanoleuca. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.