The giant panda (Ailuropoda melanoleuca), also known as the panda bear or simply panda, is a bear species endemic to China. It is characterised by its white coat with black patches around the eyes, ears, legs and shoulders. Its body is rotund; adult individuals weigh and are typically long. It is sexually dimorphic, with males being typically 10–20% larger than females. A thumb is visible on its forepaw, which helps in holding bamboo in place for feeding. It has large molar teeth and expanded temporal fossae to meet its dietary requirements. It can digest starch and is mostly herbivorous with a diet consisting almost entirely of bamboo and bamboo shoots.
The giant panda lives exclusively in six montane regions in a few Chinese provinces at elevations of up to . It is solitary and gathers only in mating seasons. It relies on olfactory communication and uses scent marks as chemical cues and on landmarks like rocks or trees. Females rear cubs for an average of 18 to 24 months. The oldest known giant panda was 38 years old.
As a result of farming, deforestation and infrastructural development, the giant panda has been driven out of the lowland areas where it once lived. The Fourth National Survey (2011–2014), published in 2015, estimated that the wild giant panda population aged over 1.5 years, excluding dependent young, had increased to 1,864 individuals; based on this number, and using the available estimated percentage of cubs in the population (9.6%), the total population comprised approximately 2,060 adult individuals as of 2018. Since 2016, it has been listed as Vulnerable on the IUCN Red List. In July 2021, Chinese authorities also classified the giant panda as vulnerable. It is a conservation-reliant species. By 2007, the captive population comprised 239 giant pandas in China and another 27 outside the country. It has often served as China's national symbol, appeared on Chinese Gold Panda coins since 1982 and Chinese Silver Panda coins since 1983, and was one of the five Fuwa mascots of the 2008 Summer Olympics.
Etymology The word panda in English was borrowed from French, but no conclusive explanation of the origin of the French word panda has been found.Oxford English Dictionary, s.v. panda n. 1. The closest candidate is the Nepali word ponya, possibly referring to the adapted wrist bone of the red panda, which is native to Nepal. In many older sources, the name "panda" or "common panda" refers to the red panda (Ailurus fulgens), which was described some 40 years earlier and over that period was the only animal known as a panda. The binomial name Ailuropoda melanoleuca means black and white (melanoleuca) cat-foot (ailuropoda).
Since the earliest collection of Chinese writings, the Chinese language has given the bear many different names, including mò (, ancient Chinese name for giant panda),Harper, Donald (2013), "The Cultural History of the Giant Panda (Ailuropoda melanoleuca) in Early China", Early China 35/36: 185–224. (abstract ) huāxióng (; "spotted bear") and zhúxióng (; "bamboo bear"). The most popular names in China today are dàxióngmāo (; ), or simply xióngmāo (; ). As with the word panda in English, xióngmāo () was originally used to describe just the red panda, but dàxióngmāo () and xiǎoxióngmāo (; ) were coined to differentiate between the species.
In Taiwan, another popular name for panda is the inverted dàmāoxióng (; ), though many encyclopedias and dictionaries in Taiwan still use the "bear cat" form as the correct name. Some linguists argue, in this construction, "bear" instead of "cat" is the base noun, making the name more grammatically and logically correct, which have led to the popular choice despite official writings. This name did not gain its popularity until 1988, when a private zoo in Tainan painted a sun bear black and white and created the Tainan fake panda incident.
Taxonomy For many decades, the precise taxonomic classification of the giant panda was under debate because it shares characteristics with both bears and raccoons. In 1985, molecular studies indicated that the giant panda is a true bear, part of the family Ursidae. These studies show it diverged about from the common ancestor of the Ursidae; it is the most basal member of this family and equidistant from all other extant bear species.
Subspecies
Two subspecies of giant panda have been recognized on the basis of distinct cranial measurements, colour patterns, and population genetics. The nominate subspecies, A. m. melanoleuca, consists of most extant populations of the giant panda. These animals are principally found in Sichuan and display the typical stark black and white contrasting colours. The Qinling panda, A. m. qinlingensis, is restricted to the Qinling Mountains in Shaanxi at elevations of . The subspecies has a slightly higher tendency towards a brown and white coloring, rather than the usual black and white coloring, although most examples exhibit the normal coloration. The skull of A. m. qinlingensis is smaller than its relatives, and it has larger molars.
A detailed study of the giant panda's genetic history from 2012 confirms that the separation of the Qinling population occurred about 300,000 years ago, and reveals that the non-Qinling population further diverged into two groups, named the Minshan and the Qionglai-Daxiangling-Xiaoxiangling-Liangshan group respectively, about 2,800 years ago.
Phylogeny Of the eight extant species in the bear family Ursidae, the giant panda's lineage branched off the earliest.
Distribution and habitat The giant panda is endemic to China. It is found in small, fragmented populations in six mountainous regions in the country, mainly in Sichuan, and also in neighbouring Shaanxi and Gansu. Successful habitat preservation has seen a rise in panda numbers, though loss of habitat due to human activities remains its biggest threat. In areas with a high concentration of medium-to-large-sized mammalssuch as domestic cattle, a species known to degrade the landscapethe giant panda population is generally low. This is mainly attributed to the panda's avoidance of interspecific competition.
The species has been located at elevations of above sea level. They frequent habitats with a healthy concentration of bamboos, typically old-growth forests, but may also venture into secondary forest habitats. The Daxiangling Mountain population inhabits both coniferous and broadleaf forests. Additionally, the Qinling population often selects evergreen broadleaf and conifer forests, while pandas in the Qionglai mountainous region exclusively select upland conifer forests. The remaining two populations, namely those occurring in the Liangshan and Xiaoxiangling mountains, predominantly occur in broadleaf evergreen and conifer forests.
Giant pandas once roamed across Southeast Asia from Myanmar to northern Vietnam. Their range in China spanned much of the southeast region. By the Pleistocene, climate change affected panda populations, and the subsequent domination of modern humans led to large-scale habitat loss. Subfossil remains from sinkholes suggest that they still inhabited the Gaoligong Mountains of Yunnan Province, on the border between China and Myanmar, as recently as 5,000 years ago. This area suffered heavy deforestation around the time of the early Ming Dynasty, which may have been the event that extirpated pandas from the area. In 2001, it was estimated that the range of the giant panda had declined by about 99% of its range in earlier millenniums.
Description
The giant panda has a body shape typical of bears. It has black fur on its ears, limbs, shoulders and around the eyes. The rest of the animal's coat is white. The giant panda's distinctive coloration appears to serve as camouflage in both winter and summer environments as they do not hibernate. The white areas serve as camouflage in snow, while the black shoulders and legs conceal them in shade. Studies in the wild have found that when viewed from a distance, the panda displays disruptive coloration, while up close, they rely more on blending in. The black ears may be used to display aggression, while the eye patches might facilitate them identifying one another. The giant panda's thick, woolly coat keeps it warm in the cool forests of its habitat.
The panda's skull shape is typical of durophagous carnivorans. It has evolved from previous ancestors to exhibit larger molars with increased complexity and expanded temporal fossa. A study revealed that a giant panda had a bite force of 1298.9 Newton (BFQ 151.4) at canine teeth and 1815.9 Newton (BFQ 141.8) at carnassial teeth. Finite element analysis has found that pandas have the highest bite force relative to their body size among ursids. The giant panda has the largest masticatory muscles among bears, being at least twice heavier than those of an American black bear or a polar bear of the same brain mass; digastric muscle is equal to 30% of brain mass in giant panda compared to 10% in black bear. Adults measure around long, including a tail of about and tall at the shoulder. Males can weigh up to . Females are generally 10–20% smaller than males. They weigh between and . The average weight for adults is .
The giant panda's paw has a digit similar to a thumb and five fingers; the thumb-like digit is actually a modified sesamoid bone that helps it to hold bamboo while eating. The evolution of the panda's pseudo-thumb may have occurred because the first digit of its forepaws, equivalent to the thumb in primates, is not opposable and is aligned with the rest of the digits. The giant panda's tail, measuring , is the second-longest in the bear family after the sloth bear.
Ecology Diet
Despite its taxonomic classification as a carnivoran, the giant panda's diet is primarily herbivorous, with approximately 99% of its diet consisting of bamboo. However, the giant panda still has the digestive system of a carnivore, as well as carnivore-specific genes, and thus derives little energy and little protein from the consumption of bamboo. The ability to break down cellulose and lignin is very weak, and their main source of nutrients comes from starch and hemicelluloses. The most important part of their bamboo diet is the shoots, that are rich in starch and have up to 32% protein content. Accordingly, pandas have evolved a higher capability to digest starches than strict carnivores. Raw bamboo is toxic, containing cyanide compounds. Pandas' body tissues are less able than herbivores to detoxify cyanide, but their gut microbiomes are significantly enriched in putative genes coding for enzymes related to cyanide degradation, suggesting that they have cyanide-digesting gut microbes. It has been estimated that an adult panda absorbs of cyanide a day through its diet. To prevent poisoning, they have evolved anti-toxic mechanisms to protect themselves. About 80% of the cyanide is metabolized to less toxic thiocyanate and discharged in urine, while the remaining 20% is detoxified by other minor pathways.
During the shoot season from April to August, the giant panda stores a large amount of food in preparation for the months succeeding this seasonal period, in which it lives off a diet of bamboo leaves. The average giant panda eats of bamboo shoots per day to compensate for the limited energy content of its diet. Ingestion of such a large quantity of material is possible and necessary because of the rapid passage of large amounts of indigestible plant material through the short, straight digestive tract. Such rapid passage of digesta limits the potential of microbial digestion in the gastrointestinal tract, limiting alternative forms of digestion. Given this voluminous diet, the giant panda defecates up to 40 times a day.