Ailuropoda melanoleuca (David, 1869)

Don E. Wilson & Russell A. Mittermeier, 2009, Ursidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 448-497 : 487

1.

Giant Panda

Ailuropoda melanoleuca

French: Ours panda / German: Bambusbar / Spanish: Panda

Other common names: Da Xiong Mao (meaning large bear cat)

Taxonomy. Ursus melanoleucus David, 1869 ,

Sichuan Province, China.

Previously included in genus Ursus . Once placed in a separate family, morphological and molecular evidence now strongly supports placement in Ursidae . No subspecies yet recognized, although one population in Qinling Mountains, Shaanxi Province, shows differences in cranial and dental morphology, pelage characteristics, and genetics indicative of isolation for several thousand years, and a subspecies designation (ginlingensis) has been proposed.

Distribution. C China (Sichuan, Gansu & Shaanxi Provinces).

Descriptive notes. Head-body 120-180 cm, tail 10-16 cm; males weigh 85-125 kg (sometimes exceeding 150 kg in captivity), about 10-20% more than females, which weigh 70-100 kg. Stocky, barrel-shaped body, large forelimbs, wide massive head with short muzzle and erect ears (10 cm). Hairs are coarse and oily. Specific name melanoleuca refers to distinctive black and white color pattern, which is unique among mammals. Face is white with an oblong black patch around each eye, black ears, and a black nose. Forelegs are black, continuing up over shoulders with a narrower band across the back. Hindlegs below the hips are also black. The remainder of the body, including the tail, is white. Occasionally, individuals may have more brown than black coloration. Forepaws are modified with a greatly enlarged radial sesamoid bone, which functions as a sixth digit for grasping bamboo. This “false thumb” is nearly equal in size to the metacarpal bones of the five true digits, and has its own pad that opposes the first digit, although it cannot be moved like an independent thumb. Bamboo is held within the haired furrow between the digits and plantar (palmar) pad, which can be tightly flexed. The Giant Panda’s generic name, meaning panda foot, derives from the foot’s likeness to the structure and function of the foot of the Red Panda, a bamboo-eater that was discovered and named earlier. Claws are short, both front and rear.

Habitat. Occupy temperate montane forests with dense stands of bamboo at altitudes of 1200-4100m, or more typically 1500-3000m. Bamboo is a dominant understory plant in broad-leaved, broad-leaved mixed with conifer, and subalpine conifer forests in the mountainous regions of central China. However, the type and density of bamboo greatly affect habitat use by Giant Pandas. The growth rate of bamboo, and hence its suitability to Pandas,is also related to the amount of overstory tree canopy. Remaining habitat for Pandas is steep and rugged, being the only land that was not farmed and settled by people in a once-extensive range that extended from Beijing to eastern China and south to present day Vietnam and Myanmar. Within this remaining habitat, Pandas seek areas with relatively gentle slopes and high moisture.

Food and Feeding. Their diet is almost entirely bamboo (over 99%); however, they occasionally feed on leaves, stems or roots of other plants as well as some meat, from rodents and young ungulates, either killed or scavenged. During large-scale flowering and die-off of bamboo, individuals may seek other foods, including crops and human garbage. For unknown reasons, some individuals do this even when bamboo is readily available. Across the six mountain ranges that they inhabit, Giant Pandas utilize over 60 species of bamboo, 35 of which constitute their main food source. They select species higher in protein and lower in fiber, hence more digestible. They use different species of bamboo in different elevational bands, varying with the seasons and coinciding with the germination and growth of the plants. They eat different parts of bamboo at different times of year, alternating between young tender leaves and shoots, versus stems and branches. They prefer shoots and stems of certain lengths and diameters, selecting those that are easier to hold and chew. Pandas sit or recline to eat. Holding a stem in one paw, a Panda inserts it in the side of its mouth and repeatedly and rapidly bites off chunks approximately the width of its palate, chewing very little. Scats of any individual Panda thus have intact fragments of bamboo that are all approximately the same length. This characteristic has been exploited in population surveys, where the size of bamboo fragments in scats is used to differentiate individuals with overlapping home ranges.

Activity patterns. Pandas are active about 50% of the day, mostly collecting or eating bamboo. Activity occurs rather uniformly through the day and night, in bursts of a few hours. Little variation occurs seasonally. Unlike other bears, which exhibit an energymaximizing strategy, increasing consumption and activity when food is most plentiful, Pandas are least active when feeding on abundant and nutritious leaves. Because food is available throughout the year, Pandas do not hibernate, although during cold and snowy conditions they may take temporary shelter in hollow trees, rock crevices, and caves. They climb trees, although infrequently, to escape danger, to rest, or in courtship—during the mating season males may vocalize from trees to attract females, and estrous females may climb to fend off suitors. However, they spend less time in trees than several other species of bears (Andean Bears, Sun Bears, Asiatic Black Bears) because they do not feed there.

Movements, Home range and Social organization. Individuals have home ranges of 1-60 km?, averaging 5-15 km? depending on gender and habitat. Range size changes seasonally, and they make seasonal elevational shifts (sometimes referred to as vertical migrations), which vary by area, corresponding with growth patterns of various kinds of bamboo. Typically they descend to lower elevations during winter, to escape deep snow, and to high elevations in summer. They can move several hundred meters in elevation in just a few days. Home ranges overlap, but pandas may remain in smaller core areas of only about 30 ha for half their time; these core ranges overlap little among animals of the same sex, but adult males overlap the core ranges of several females. Communication and spacing appears to be maintained by extensive scent marking, using secretions from anogenital glands. Secretions are often deposited on stumps, logs or trees along prominent ridges. One study used fecal genetics to investigate relatedness of Pandas living in the same vicinity, and inferred that, unlike all other bears, females rather than males disperse from their natal area. In another study, two radio-collared males settled near their mother, whereas two young females dispersed. As Panda range has expanded, several young, apparently dispersing females have appeared in several new areas, including a large city.

Breeding. Mating occurs from March through May. Vocalizations (bleating, chirping) and scent marking are used to attract mates. Pairs may remain together for days or weeks prior to mating. Both sexes may mate with multiple (3-5) partners. Peak estrus lasts less than one week. Females use rock dens or hollow trees for birthing. Cubs are born in August or September, 3-5-5 months after mating; a variable period of delayed implantation accounts for the variability in total gestation. At 80-200 grams, the infant at birth is only about 0-1% of the mother’s weight, one-third to one-quarter that of other bears. Infants are born pink in color, with short, sparse white hair; the typical black and white pelage is achieved by three weeks of age. Litter size at birth is often two, generally born about two hours (but up to 36 hours) apart; however, the mother raises just the first born, if it is healthy. Thus, functional litter size in the wild is only one. In captivity, females can be fooled into raising two cubs by switching them every twelve hours. This is the only species of bear to regularly give birth to more cubs than it can raise—the explanation for this unusual reproductive strategy remains elusive. Also, unusual for bears, Panda mothers change dens multiple times, carrying their cub in their mouth, and also periodically leave the den to feed. During the birthing process they only fast for 2-3 weeks. Pandas are often erroneously believed to be poor breeders. This impression stemmed from the previous low reproductive performance of captive animals, now known to have resulted from inadequate captive conditions. Studies of wild Pandas indicate that their reproductive rates are comparable to some other species of bears, with cub production beginning at 5-7 years and inter-litter intervals of two or three years. Breeding continues into the early-20s, so a female could wean six or more cubs in her lifetime.

Status and Conservation. CITES Appendix I. Listed as Endangered on The IUCN Red List. The Giant Panda is considered a threatened and precious species in China. They are also listed as Endangered under the USA Endangered Species Act, thereby regulating import of captive animals into the USA. Their total population in the wild has been estimated at less than 2000, but this may be revised as better methodology is developed for estimating numbers (e.g. using DNA in their feces to identify individuals). They are a Category I species (maximum level of protection) under the Chinese Wildlife Conservation Law. A national conservation plan, adopted by the Chinese government in 1992, guides conservation initiatives for this species. Intentional poaching of Pandas has been largely curtailed by severe penalties and increased patrolling in their remaining habitats. Markets for their skins have virtually disappeared, and other body parts are not used in traditional Chinese medicine. However, they are still sometimes killed in snares set for Musk Deer and other species. Limited and degraded habitat remains their greatest threat. The species only exists in portions of six mountain ranges separated by expanses of agriculture, and within these, inhabitable bamboo forests are separated by a patchwork of clearings and forested areas without bamboo. Conservation measures have included the establishment of a network of more than 60 Panda reserves, a ban on logging, and a policy that compensates farmers who convert agricultural fields on steep slopes to forest. However, small population size and restricted total range remains a threat to the viability of this species. A further threat relates to the panda’s reliance on bamboo for food. Bamboo is subject to periodic, synchronous flowering and dieoffs at intervals of 15-120 years, and the fragmented habitat restricts where Pandas can move when such die-offs occur. Effects of climate change on bamboo abundance and flowering cycles are as yet very uncertain. Captive breeding in China has now succeeded (with the aid of artificial insemination) to the extent that captive facilities will soon be overpopulated, providing a potential stock for augmenting wild Panda populations. However, the lack of suitable release sites—having adequate habitat but few resident pandas—Ilimits hopes of eventually releasing many of these captive Pandas into the wild.

Bibliography. Endo et al. (1999), Garshelis et al. (2008), Johnson, K.G. et al. (1988b), Lindburg & Baragona (2004), Liu et al. (2005), Loucks, Lu, Dinerstein, Wang, Fu & Wang (2003), Loucks, Lu, Dinerstein, Wang, Olson et al. (2001), LG, Johnson et al. (2001), LU, Pan et al. (2000), Li, Wang & Garshelis (2007), Lumpkin & Seidensticker (2002), Pan et al. (2001), Reid & Gong (1999), Schaller, Hu et al. (1985), Schaller, Teng et al. (1989), Wan et al. (2005), Xu et al. (2007), Zhan, Li et al. (2006), Zhan, Zhang et al. (2007), Zhu et al. (2001).

Figures

1. Giant Panda (Ailuropoda melanoleuca), 2. Andean Bear (Tremarctos ornatus), 3. Sun Bear (Helarctos malayanus), 4. Sloth Bear (Melursus ursinus), 5. Asiatic Black Bear (Ursus thibetanus), 6. American Black Bear (Ursus americanus)

Distribution. C China (Sichuan, Gansu & Shaanxi Provinces).