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 100 to 115 kg (220 to 254 lb) and are typically 1.2 to 1.9 m (3 ft 11 in to 6 ft 3 in) 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 3,000 m (9,800 ft). It is solitary and gathers only in mating seasons. It relies on olfactory communication to communicate 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.
A bear that quit meat for bamboo and never looked back.
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 117.5 kg (259 lb) 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 more than twice as large as those of the American black bear with an equivalent brain weight; digastric muscle is equal to 30% of brain weight in giant panda compared to 10% in black bear.
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 mammals—such as domestic cattle, a species known to degrade the landscape—the 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 2,400 to 3,000 m (7,900 to 9,800 ft) 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.
Ecology
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 54.8–66.1 mg (0.846–1.020 gr) 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.
Behavior
The giant panda is a terrestrial animal and primarily spends its life roaming and feeding in the bamboo forests of the Qinling Mountains and in the hilly province of Sichuan. Giant pandas are generally solitary. Each adult has a defined territory and a female is not tolerant of other females in her range. Social encounters occur primarily during the brief breeding season in which pandas in proximity to one another will gather. After mating, the male leaves the female alone to raise the cub. Pandas were thought to fall into the crepuscular category, those who are active twice a day, at dawn and dusk; however, pandas may belong to a category all of their own, with activity peaks in the morning, afternoon and midnight. The low nutrition quality of bamboo means pandas need to eat more frequently, and due to their lack of major predators they can be active at any time of the day. Activity is highest in June and decreases in late summer to autumn with an increase from November through the following March. Activity is also directly related to the amount of sunlight during colder days. There is a significant interaction of solar radiation, such that solar radiation has a stronger positive effect on activity levels of panda bears.
Conservation
The giant panda is a vulnerable species, threatened by continued habitat destruction and habitat fragmentation, and by a very low birthrate, both in the wild and in captivity. Its range is confined to a small portion on the western edge of its historical range, which stretched through southern and eastern China, northern Myanmar, and northern Vietnam. The species is scattered into more than 30 subpopulations of relatively few animals. Building of roads and human settlement near panda habitat, result in population declines. Diseases from domesticated pets and livestock is another threat. By 2100, it is estimated that the distribution of the giant panda will shrink by up to 100%, mainly due to the effects of climate change. The giant panda is listed on CITES Appendix I, meaning trade of its parts is prohibited and that it requires this protection to avoid extinction. It has been protected by China's 1988 Wildlife Conservation Law.