Giant panda

Diet: Herbivore

• Wild – almost exclusively bamboo (25-35 pounds per day); when bamboo availability is limited, they may feed on crops or local fruits and tree bark; wild giant pandas have also been observed consuming carrion.

  • • Wild giant pandas may eat up to 60 different species of bamboo, but their primary diet consists of about 35 species. Not all species grow in each of the disjunct forests. They seasonally adjust which species they forage and what part(s) of the plant they consume to take advantage of key nutrients.

    • Giant pandas cannot digest bamboo efficiently, due to their digestive tracts resembling that of other carnivores. To compensate for this, giant pandas consume large volumes of bamboo. Wild giant pandas spend over half of their time (about 14 hours per day) foraging for and eating bamboo. During other hours, they conserve energy by resting. Other energy conservation strategies include avoiding travel up steep slopes, communicating via scent, and remaining in small ranges of which they do not defend boundaries.

    • Research suggests that giant pandas prefer bamboo sources with higher levels of protein. Across their range, wild giant pandas show a preference for fresh bamboo leaves, which are higher in protein than stems, branches, or withered leaves. They also prefer species with higher crude protein levels.

• Zoo – bamboo supplemented with commercially prepared leafeater biscuits and fresh produce (apple, banana, sweet potato, pear); they receive sugar cane as a favorite enrichment item.

  • • Each of the adult giant pandas are offered around 80-100 pounds of bamboo daily and they eat about one-third of that.

    • You can tell by their feces which part of the bamboo the giant pandas have been eating. If their poop is yellow, they’ve been culming. If it’s green, they’ve been leafing and you can see the leaves in their poop.

    • Both in the wild and at the Zoo, giant pandas show a strong preference for fresh bamboo shoots. If the bamboo supply is sufficient, we feed the pandas shoots only during the spring to replicate their natural diet.

Bamboo

• Bamboo is a group of perennial evergreens in the grass family. Depending on local soil and climatic conditions, it is capable of growing up to almost 24 inches (60 centimeters) a day. Bamboos are of cultural and economic significance in many places, especially in southern and southeast Asia. They can be used to make construction materials, furniture, clothing, and various food items.

• There are approximately 1,450 species of bamboo, exhibiting great variation in height from only one foot to more than 120 feet tall. Diameter also varies from a fraction of an inch to 12 inches.

• Some species flower annually while others may only flower every 100+ years. In some species, the entire grove may die after flowering. Large-scale bamboo die-offs have historically caused giant panda population declines, delays in estrous cycles, and human-panda conflict when they forage into crop lands.

• Bamboo Technicians (part of the Animal Nutrition Kitchen team) work full-time to harvest donated bamboo within about a 50-mile radius of the Zoo and will travel as far as Dahlonega for a good harvest site. They harvest up to 2,500 pounds of bamboo each week.

• Before accepting donations, the Bamboo Team evaluates the growth site to determine if the species is one giant pandas will eat and observe the condition of the site.

• The giant pandas at Zoo Atlanta enjoy several species of bamboo throughout the year including henon, yellow groove, arrow, river cane, and rubromarginata.

Reproduction

Mating

• Adults are solitary and only come together to breed. Outside of the spring breeding season, they avoid one another using olfactory communication.

• Mating occurs from late winter to early spring, generally in March to May. During this time, males move throughout their range to look for signs (scent marks) of estrous females. When a male finds a female, he stays nearby to monitor the female’s reproductive status. Once her peak reception has passed, he will move on to search for more females.

• Females are in estrus for 12-25 days but are sexually receptive for only a few days when their estrogen concentration reaches a peak. This occurs only once per year. Ovulation occurs during the peak estrus period, resulting in only a 24-72 hour window in which the female can become pregnant.

• Female behavior often changes notably during the estrous period.

  • • Initially, aggressive behaviors increase. This is believed to prevent mating before the peak estrous period.

    • Bleating, chirping, and posturing (all affiliative behaviors) increase as she approaches peak estrus.

    • After the peak, females increase their bamboo intake for a short time before returning to normal levels.

• In the wild, both sexes may mate with multiple partners in a breeding season.

Gestation and Birth

• Gestation length varies from about three to 5.5 months (84-184 days) due to delayed implantation, in which a fertilized egg floats freely for some time before attaching to the uterine wall. Once this occurs, “true gestation,” the period of fetal development, lasts for approximately 45-50 days. Average gestation is about 4.5 months.

• Most wild births occur in August and September. Like other bear species, giant pandas give birth in dens such as hollow tree bases, under large roots, or in natural rock caves. Unlike other bears, giant pandas have been recorded regularly changing dens; however, this could be in response to disturbance by researchers.

• Litters are generally only one or two cubs, with rare cases of triplets in human care. When wild giant pandas give birth to twins, they typically only raise one cub.

• In human care, giant pandas have successfully raised two cubs with assistance. While the mother cares for one, human caregivers look after the other. They “swap” cubs in intervals that vary throughout cub development to ensure both cubs receive attention and nutrition from the mother. Only two females in human care have successfully raised twins on their own.

Giant Panda Cub Development

• At birth, cubs weigh only three to five ounces (85-140 grams). Of all placental mammals, newborn giant pandas are smallest in size relative to their mothers, who are 800-900 times heavier than their cubs.

• At birth, giant panda cubs have sparse white hair covering their pink skin. After about 10 days, they begin to develop the characteristic panda coloring, which darkens from grey to black throughout the first month of life.

• Newborn giant panda cubs are very vocal, emitting a squawking noise when maternal attention is needed during the first two to three months of life.

• Their eyes are not fully developed at birth and do not open until they are 40-50 days old. Their sight develops at about 90 days of age.

• After about two months, cubs begin attempting to crawl, but it takes them a month or two to master the skill.

• Cubs may begin experiencing their first dental eruptions at 75-90 days of age.

• Cubs develop their full coat around 90 days of age. At this time, they can leave the den with the ability to thermoregulate. Around this time is also when they become more confident walkers. Dams and their cub usually emerge from the den at around 95-125 after parturition (birth).

• Cubs begin “sampling” bamboo around five or six months of age. By one year of age, bamboo is their primary source of nutrition, but they do not fully wean until between 18-24 months of age.

• They are considered infants until 1.5 years of age and sub-adults until 4.5 or 5 years of age.

Additional Information

• Female giant pandas fast for two to three weeks while in the maternity den. After giving birth, they do not leave the den for several days. After five or six days, they may begin leaving the den to defecate but will continue fasting until the cub is at least 2 weeks old. Female giant pandas in human care fast similarly.

• Giant pandas reach sexual maturity from 5.5 to 6.5 years of age. Female giant pandas typically give birth for the first time between 5 and 7 years of age. The average litter interval is about two years.

• Male giant pandas can determine an individual’s sex and reproductive status (estrus or non-estrus) from that individual’s scent (see below for more information on chemical communication). Males bleat (vocalize) more in response to estrous female scents. Researchers believe this is a way of alerting the female to his presence and affiliative intentions. Females also bleat more in response to males compared to female odors.

• Newborn giant panda cubs’ tails are disproportionately long at birth, making up about 1/5 to 1/3 of their total body length.

• A mother panda will lick her cub’s anogenital area to stimulate waste excretion. The mother consumes the cub’s waste to eliminate the smell and avoid attracting predators.

• The first recorded giant panda birth in human care was in 1963 at the Peking Zoo in Beijing, which was also the first zoo to artificially inseminate a giant panda in 1978.

Interpretive Information

• Like other bears, giant pandas are members of the Ursidae family. Molecular studies have found that they share a common ancestor with other extant bear species. Giant pandas diverged from the main bear lineage 15 to 25 million years ago. Comparative studies of bear bile acids suggest the giant panda is older than any other extant bear species in terms of evolutionary age.

• The Chinese characters for giant panda translate to “large bear cat.”

• The giant panda’s scientific name, Ailuropoda melanoleuca, means “black and white cat-footed bear” in Latin.

• Although the two species are not closely related, there are some similarities between giant pandas and red pandas. These include tooth and skull structure, the presence of a pseudo-thumb, a primarily bamboo diet, scent glands, and scent marking behavior.

• Giant pandas in the Qinling Mountains represent a distinct genetic cluster as evidenced by differences in skull morphology and fur color. There is debate as to whether to classify this population as a sub-species.

• Genome sequences have revealed that the modern giant panda has lost the ability to taste protein, representing a relatively recent adaptation to a plant-based diet.

• Traditional Tibetan mythology of unknown origin details how giant pandas obtained their fur coloring. According to the tale, giant pandas were originally all white in color. One day, their friend, a young shepherdess, was killed by a leopard while trying to defend the pandas from attack. At the funeral, following local custom, the pandas covered their arms with ashes. They then used their ashy paws to wipe tears from their eyes and cover their ears from mourners’ cries. The grief-stricken pandas hugged one another, leaving black coloring on other parts of the body as well.

• The Chinese government has conducted population surveys approximately every 10 years since 1974. The most recent, the Fourth National Survey (2011-2014) surveyed 4.36 million hectares (about 10 million acres) of land.

• Data on predation is limited. Depending on the region, predators of the giant panda may include common leopards, dholes, yellow-throated martens, Asian golden cats, and clouded leopards. Infants in dens and juvenile giant pandas are the most likely targets.

• The giant panda has been the logo of the World Wildlife Fund (known as the World Wide Fund for Nature in some countries), or WWF, since its founding in 1961.

Behavior

• Giant pandas are considered crepuscular, with activity peaking at dusk and dawn, but some activity occurs throughout all hours.

• They spend about 40% of their time resting, usually for two to four hours at a time.

• Aggressive encounters between males are rare and are most likely to occur when females are in estrus.

• Giant pandas may climb into trees to sun, rest, or escape danger. Otherwise, adult giant pandas do not regularly climb trees. Young giant pandas may wait in a tree for several hours while their mother is foraging.

Vocal Communication

• Vocalization is infrequent and generally associated with courting and close-range social interactions.

• Thirteen auditory signals have been identified in adult giant pandas. They can generally be divided into categories based on presumed function. However, calls may be combined in sequences, providing an intricate system of signals to convey fluctuating emotional and motivational states.

  • • Social (promote friendly interaction)

      • • Bleat: a rapidly modulated sound similar to that of a goat; primarily heard during the mating season; may assist in individual recognition; in males, provides information about the caller’s testosterone levels

    • Apprehensive (low intensity threats)

      • • Huff: air exhalation ranging from soft panting to loud coughing; somewhat threatening and believed to denote apprehension; generally non-vocal

        • Snort: similar to a huff, except air is primarily expelled through the nose instead of the mouth; also believed to be threatening; generally non-vocal

        • Chomp: a repetitive sound with two components, produced when a panda opens and closes its mouth rapidly; one sound is a click as the teeth are brought together, and the other is a smack; believed to be a light threat that lacks aggressive intent; generally non-vocal

        • Distress (lack of aggressive intent)

        • Honk: a nasal grunt, emitted singly or repetitively in a long series; believed to indicate mild distress

        • Squeal: a high-pitched call emitted when an animal feels threatened or is attacked by another; indicates distress, apprehension and lack of aggressive intent

    • Aggressive

      • • Growl: a low-pitched, pulsed vocalization similar to a dog’s growl; represents an aggressive threat

        • Roar: an exceptionally loud and intense vocalization; represents an aggressive threat of the highest level

    • Circumstantial (function varies by circumstance)

      • • Moan: highly variable, ranging from a sharp hoot to a low-pitched moo; believed to be a mild warning; associated with the mating season and may function as a long-distance advertisement

        • Bark: similar to a dog’s bark; believed to express excitement; depending on the situation, it may convey either a warning or an advertisement of the animal’s location

        • Chirp/Yip: a high-pitched call that descends rapidly in pitch toward the end; higher intensity calls are believed to indicate a higher level of emotion; contexts and function similar to those of the bark; may help promote social contact during the mating season

        • Squawk: a loud vocalization of varying length and pitch emitted by young cubs during the first few months of life when cold or otherwise uncomfortable; the greater the distress, the higher the pitch

        • Whine: a high-pitched, medium intensity vocalization intended to communicate that attention is unwanted or too intense; usually occurs when animals are wrestling or when an animal is directing a behavior at an animal engaged in another activity; typically exhibited by cubs and sub-adults

Chemical Communication

• Giant pandas are highly olfactory and use chemical communication to locate and choose mates, regulate their use of space, and assess potential competitors.

• They secrete a waxy substance, containing fatty acids and aromatic compounds, from a specialized anogenital gland, and also use urine as a chemical signal.

• Where territories overlap, giant pandas use specific sites, called scent stations, to deposit scent and investigate the odors of other pandas – like a community bulletin board. They will also strip tree bark, paw the ground, rub, and roll in these areas.

• There are four postures used to scent-mark at varying heights above the ground.

  • • Handstand: individual “walks” their hind legs as high up a structure (in the wild, usually a tree) as they can to secrete scent (only observed in adult males, usually only a urine mark)

    • Leg-cock: raise one leg against a vertical surface (mostly used by males)

    • Reverse: the individual backs into a vertical surface to secrete scent (observed in both sexes)

    • Squat: scent is deposited on the ground (observed in all individuals but mostly in subadults and females)

• Giant pandas, especially males, may exhibit the flehmen response in response to novel conspecific odors. This behavior, along with anatomical evidence, suggests the presence of a vomeronasal organ (VNO), also known as Jacobson’s organ, for processing scent particles.

• Giant pandas can determine an individual’s identity, distinguish between kin and non-kin, and detect the sex, age, and reproductive condition from scent marks.

History of Giant Pandas in the United States

• The giant panda was first described to the western world by Pere Armand David, a French missionary and naturalist, in 1869.

• The first live giant panda exported to the United States (1936) was exhibited on a tour of San Francisco, Chicago and New York before eventually settling at Chicago’s Brookfield Zoo. It only survived a few years and died in 1938. No other giant pandas were exported to the United States until 1972 when China gifted two giant pandas to the Smithsonian’s National Zoological Park.

• In the 1980s, China granted short-term loans (from a few weeks to a few months) at high financial cost that did not directly benefit wild populations. In 1988, the United States banned the importation of giant pandas.

• During the 1990s, the U.S. Fish and Wildlife Service developed strict guidelines for giant panda loans. Among other things, these guidelines require any loan to enhance conservation of wild pandas through research.

Giant Panda Research at Zoo Atlanta

• Behavioral research has been a hallmark of Zoo Atlanta’s giant panda program since its inception. Primary areas of interest include maternal behavior, cognitive ability, and visual perception.

• Research at Zoo Atlanta provides evidence that giant pandas can see in color.

Updated November 2020