Ailuropoda melanoleuca (David, 1869)

Taxonomic Name

Scientific name: Ailuropoda melanoleuca (David, 1869).

Body Shape

Description: The giant panda has a bear-typical body shape.

Fur Coloration

It has black fur on its ears, limbs, shoulders, and around its eyes, with the rest of its coat being white.

Coloration Function

The species' distinctive coloration is thought to act as camouflage in both winter and summer environments, since giant pandas do not hibernate: white fur camouflages them against snow, while black shoulders and legs hide them in shade.

Wild studies show that from a distance, the panda has disruptive coloration, while it relies more on blending in when viewed up close.

Marking Function

Black ears may be used to display aggression, and eye patches may help giant pandas identify one another.

Coat Insulation

The giant panda's thick, woolly coat keeps it warm in the cool forests of its habitat.

Skull Structure

Its skull shape is typical of durophagous carnivorans.

It has evolved from ancestors to have larger, more complex molars and an expanded temporal fossa.

Bite Force Measurement

One study recorded that a 117.5 kg (259 lb) giant panda had a bite force of 1298.9 Newton (BFQ 151.4) at the canine teeth, and 1815.9 Newton (BFQ 141.8) at the carnassial teeth.

Finite element analysis confirms that among ursids, giant pandas have the highest bite force relative to their body size.

Masticatory Muscles

Giant pandas have the largest masticatory muscles of any bear; for individuals with equivalent brain weight, their masticatory muscles are more than twice as large as those of the American black bear.

The giant panda's digastric muscle equals 30% of its brain weight, compared to 10% in the American black bear.

Adult Body Size

Adult giant pandas measure 1.2 to 1.9 m (3 ft 11 in to 6 ft 3 in) in total length, including a 10–15 cm (3.9–5.9 in) tail, and stand 60 to 90 cm (24 to 35 in) tall at the shoulder.

Male Weight

Males can weigh up to 160 kg (350 lb).

Female Weight

Females are generally 10–20% smaller than males, weighing between 70 kg (150 lb) and 125 kg (276 lb).

The average adult weight is 100 to 115 kg (220 to 254 lb).

Paw Adaptation

The giant panda's paw has one thumb-like modified sesamoid digit plus five regular fingers; the pseudo-thumb helps it hold bamboo while eating.

The pseudo-thumb likely evolved because the giant panda's original first forepaw digit, equivalent to a primate thumb, is not opposable and aligns with the rest of the digits.

Tail Length

At 10 to 15 cm (3.9 to 5.9 in) long, the giant panda's tail is the second-longest in the bear family, only shorter than that of the sloth bear.

Current Distribution

Distribution and habitat: The giant panda is endemic to China, with small fragmented populations in six of the country's mountainous regions.

Most populations live in Sichuan, with additional populations in neighboring Shaanxi and Gansu.

Primary Threat

Successful habitat preservation has led to an increase in giant panda numbers, though habitat loss from human activity remains the species' biggest threat.

Interspecific Competition

Giant panda populations are generally low in areas with high concentrations of medium-to-large mammals such as domestic cattle, which degrade the landscape; this is mostly attributed to the giant panda's avoidance of interspecific competition.

Elevation Range

Giant pandas have been recorded at elevations of 2,400 to 3,000 m (7,900 to 9,800 ft) above sea level.

General Habitat Preferences

They prefer habitats with abundant bamboo, most commonly old-growth forests, but will also use secondary forest habitats.

Regional Habitat Variation

The Daxiangling Mountain population lives in both coniferous and broadleaf forests.

The Qinling population often selects evergreen broadleaf and conifer forests, while pandas in the Qionglai mountain region exclusively select upland conifer forests.

The two remaining populations, in the Liangshan and Xiaoxiangling mountains, live mostly in broadleaf evergreen and conifer forests.

Historical Range

Giant pandas once ranged across Southeast Asia from Myanmar to northern Vietnam, and covered most of southeastern China.

Historic Population Decline

By the Pleistocene, climate change impacted giant panda populations, and the later spread of modern humans caused large-scale habitat loss.

Subfossil remains from sinkholes show that giant pandas still lived in the Gaoligong Mountains of Yunnan Province, on the China-Myanmar border, as recently as 5,000 years ago.

Heavy deforestation in this area during the early Ming Dynasty may have been the event that eliminated pandas from this region.

Range Reduction

By 2001 estimates, the giant panda's current range has declined by about 99% from its range in earlier millennia.

Sexual Maturity

Reproduction: Giant pandas reach sexual maturity between 4 and 8 years of age, and can remain reproductive until age 20.

Mating Season

Mating season occurs between March and May, when females enter an estrus period that lasts two to three days and occurs only once per year.

Mating Position

During mating, the female holds a crouching, head-down position while the male mounts her from behind.

Copulation lasts from 30 seconds to five minutes, and males may mount females repeatedly to ensure successful fertilization.

Gestation Period

Gestation lasts between 95 and 160 days; this variability occurs because fertilized eggs can remain in the reproductive tract for some time before implanting on the uterine wall.

Twin Births

Around half of all giant panda pregnancies result in twins.

If twins are born in the wild, usually only one survives: the mother chooses the stronger cub, and the weaker cub dies of starvation.

It is thought that mothers cannot produce enough milk for two cubs, as they do not store fat.

Parental Care

Fathers do not participate in raising cubs.

Newborn Characteristics

Newborn giant pandas are pink, blind, and toothless, weighing only 90 to 130 g (3.2 to 4.6 oz), approximately 1/800 of the mother's weight.

This makes the giant panda cub proportionally the smallest baby of any placental mammal.

Nursing Behavior

Cubs nurse 6 to 14 times a day for up to 30 minutes per nursing session.

For three to four hours each day, the mother may leave the den to feed, leaving the cub defenseless.

Early Fur Development

One to two weeks after birth, the cub's skin turns gray in areas that will eventually grow black hair.

A slight pink tint may appear on the cub's fur, caused by a chemical reaction between the fur and the mother's saliva.

Juvenile Development

One month after birth, the cub's full adult color pattern is developed.

A cub's fur is very soft when young, and becomes coarser as it ages.

Cubs begin to crawl between 75 and 80 days old, and mothers play with their cubs by rolling and wrestling with them.

Weaning Process

Cubs can eat small amounts of bamboo after six months, but mother's milk remains their primary food source for most of their first year.

Juvenile Independence

Giant panda cubs weigh 45 kg (99 lb) at one year old, and stay with their mothers until they are 18 months to two years old.

Birth Interval

The interval between wild births is generally two years.

Initial Captive Breeding Challenges

Initially, artificial insemination was the primary method for breeding giant pandas in captivity, because captive pandas often lost interest in mating.

This led scientists to test methods such as showing captive pandas mating videos and giving males sildenafil (commonly known as Viagra).

Captive Breeding Success

In the 2000s, captive breeding programs began seeing consistent success.

Researchers have now determined that giant pandas have breeding rates comparable to some populations of the thriving American black bear.

Frozen Sperm Insemination

In July 2009, Chinese scientists confirmed the birth of the first giant panda cub successfully conceived via artificial insemination using frozen sperm.

The technique of freezing sperm in liquid nitrogen was first developed in 1980, and this first birth was seen as a solution to limited giant panda semen availability, which had previously led to inbreeding.

Frozen panda semen can be stored for decades and shared between different zoos to support conservation of the species.

As of 2009, it was expected that zoos in destinations including San Diego (U.S.) and Mexico City would be able to provide their own semen to inseminate more giant pandas.

Interspecific Pregnancy Attempts

Attempts have also been made to produce giant pandas via interspecific pregnancy, by implanting cloned panda embryos into the uterus of another species.

These attempts have produced panda fetuses, but no live births.