- CLASS: Mammalia (Mammals)
- ORDER: Carnivora
- FAMILY: Ursidae
- GENUS: Ailuropoda
- SPECIES: melanoleuca
Giant pandas are black and white and loved all over. The giant panda is a national treasure in China and is therefore protected by law in its bamboo forest home. This unique bear has long been revered by the Chinese and can be found in Chinese art dating back thousands of years. The Chinese call their beloved pandas large bear-cats. Giant pandas have also fascinated people living outside of China; French Missionary Pere Armand David first described them for science in 1869. Now, more than 100 years later, the worldwide love for pandas has been combined with international efforts to keep them from becoming extinct.
How did the panda get its colors? We aren't exactly sure. One theory is that pandas developed the contrasting black and white colors over time so they would stand out in the forest and be able to find each other to mate. Another idea is that the broad blockings of contrasting color may serve to camouflage the panda in the bamboo or treetops. Anyone who's tried to spot one of our panda cubs up in the tree napping can verify how difficult that can be! Scientists have yet to confirm what the real purpose of the panda's coloration is. Each panda has markings that are slightly different from any another panda. There is also a rare brown and white variation of the giant panda.
Are giant pandas bears? For years scientists have wondered whether pandas are a type of bear, raccoon, or something all their own. Through studying the genetic code (DNA) in pandas’ cells, scientists have confirmed the panda's relationship with bears. Giant pandas are similar to other bears in their general looks, the way they walk and climb, their skull characteristics, and, importantly, their social system and reproductive biology. It's necessary to know that pandas are bears, because the more we know about pandas, the better we can help them reproduce and survive.
Pandas are arguably the most vocal of all the bear species. One of the most distinctive of the panda vocalizations is the “bleat.” This sounds similar to the sound a lamb or a goat kid would make, and it’s a friendly sound, a greeting. Pandas don't roar the way you think of a brown bear roaring. Other vocalizations include honks, huffs, barks, and growls. Young cubs are known to croak and squeal.
There are other ways pandas communicate, too. Both male and female pandas have a scent gland underneath their short tail that secretes a waxy substance used to leave scent marks. Pandas scent mark trees, rocks, bamboo, and bushes. The scent is pretty strong. Human noses can smell the stinky, waxy scent mark from about a foot away, but pandas are more sensitive to smell, so to them it's even stronger! We’ve discovered that a scent-marked tree or rock can serve as a community bulletin board, notifying pandas in the area what other pandas have been there and how long ago they left their scent mark. Another panda can detect the sex, age, reproductive condition, social status, and even individual identity of the scent maker—as well as how long that scent has been there.
Male pandas often perform “handstands” to leave scent marks. A handstand gets a panda’s rear end higher up the tree, so the scent mark will be higher, too. It seems that pandas are most interested in higher-placed scent marks; the panda with the highest scent mark is obviously the biggest—or at least the tallest—panda.
HABITAT AND DIET
Giant pandas live in the mountains of southwestern China, in damp, misty forests, mostly at elevations between 4,000 and 11,500 feet (1,200 to 3,500 meters). They need old-growth conifer forests with at least two bamboo species and water access. These old-growth forests provide old, hollow logs and tree stumps large enough for panda dens. Pandas stay in a home range that’s 3 to 7 square miles (8 to 18 square kilometers). In areas where food isn’t as plentiful, the home range might be a bit larger. Like other bears, pandas spend most of the day eating and sleeping.
Bamboo is the most important plant for giant pandas. They spend at least 12 hours each day eating bamboo. Because bamboo is so low in nutrients, pandas eat a lot of it daily. They grasp bamboo stalks using their five digits and a special bone that extends from their wrist called a “pseudo-thumb.” That little pseudo-thumb adeptly holds and manipulates bamboo, almost as well as your thumb does.
Pandas use their teeth to peel off the tough outer layers to reveal the soft inner tissue of the stalk. Strong jawbones and cheek muscles help pandas crush and chew the thick stalks with their flattened back teeth. Bamboo leaves are also on the menu, as pandas strip them off the stalks, wad them up, and eat them. Giant pandas have also been known to eat grasses, bulbs, fruits, some insects, and even rodents and carrion—pretty much whatever they can find.
At zoos, pandas are offered bamboo, carrots, yams, apples, and special biscuits designed for leaf-eating animals (called leafeater biscuits) that are made of grain and packed with all the vitamins and minerals pandas need.
Pandas are always associated with bamboo, but they need more than just bamboo to make a home. San Diego Zoo scientists have found that suitable panda habitat requires old-growth conifer forests with at least two species of bamboo and water access. Why is old-growth forest habitat important for pandas? It provides old, hollow logs and tree stumps large enough for panda dens, and it also provides shelter and nutrients for the bamboo growing there. The average panda’s home range is thought to be about 1.9 square miles (5 square kilometers), with male ranges larger than that of females. In areas where bamboo is not plentiful, the home range may be larger.
Pandas aren’t party animals by any stretch of the imagination. Like other bears, they spend most of the day eating and sleeping. Wild pandas are solitary by nature, and they take their own “space” seriously! Since a panda needs so much bamboo each day to survive, it only makes sense that two’s a crowd when it comes to the bamboo forest. If two pandas happen to cross paths, they’ll growl, swat, and lunge at each other, and maybe even bite each other. There are two exceptions to this less-than-welcoming attitude: the very brief mating season and mothers with cubs.
Although pandas are generally solitary as adults, they are exposed to the scents of other neighboring pandas that have crossed over their path days or weeks before. If a female is starting her estrus soon, it makes sense that she would need to advertise her status to any males that might be in the area. She scent marks, and a male that comes across her scent a few days later can recognize the change in her status via that scent mark. Our research in Wolong has confirmed that males are more interested in scent from a female who was known to be in estrus at the time she left the scent.
Once he has identified this change in a female’s status, a male remains closer to this female, assessing her status more frequently and keeping closer tabs on her so he can be present when she is ready for mating. This is important, as there is only a two- to three-day period that the female is receptive to breeding. When she is no longer receptive, the male moves on to find another willing female. He does not help raise any cubs born.
Pandas have a slow reproductive rate: mature females usually breed just once every two or three years. In the wild, a typical female panda may bear about five litters in her lifetime.
Giant pandas are only about the size of a stick of butter at birth, and they're hairless and helpless. The panda mother gives great care to her tiny cub, usually cradling it in one paw and holding it close to her chest. For several days after birth, the mother does not leave the den, not even to eat or drink!
The cub's eyes open at 50 to 60 days of age, and by 10 weeks the cub begins to crawl. Its teeth appear by the time it is 14 weeks old, and mother and cub spend much less time using their den. By 21 weeks, the cub is able to walk pretty well. At this time, the cub starts to play with its mother, and at 7 to 9 months of age, it starts attempting to eat bamboo. The cub continues to nurse until about 18 months of age. At this time, the mother is ready to send the cub off on its own, so she can prepare for her next cub.
Once a young panda reaches a weight of about 110 pounds (50 kilograms) and is about 2.5 years old, it is probably safe from predators. However, animals such as the golden cat, yellow-throated marten, dhole, and weasel prey on panda cubs and juveniles. Long ago, panda cubs were also prey to tigers and leopards, as their relatively slow gait on the ground made them easy pickings. To stay safe, solitary cubs scamper high in trees and remain there until their mother returns, spending hours and hours asleep up in those trees. When they are resting quietly in the branches, they can be hard to spot. Even the San Diego Zoo’s cubs can easily be overlooked when sleeping in trees that have been trimmed to allow for better viewing for our guests.
Today, pandas have fewer predators than they did historically. Tigers are generally not found in what remains of panda habitat, and leopards are found in reduced numbers. But the drive to remain safe is still the same, and is seen even in pandas housed in zoos and breeding centers.
AT THE ZOO
The San Diego Zoo has had a love affair with giant pandas ever since two of the black-and-white bears came to visit in 1987 for 100 days. After years of red tape and tons of application paperwork, the Zoo and China agreed on a 12-year research loan of two giant pandas, Bai Yun and Shi Shi, who arrived at the Zoo in 1996. A brand-new exhibit area was built for our panda guests—and was later expanded and renovated—called the Giant Panda Research Station. In 2008, our panda loan was extended for another five years and was renewed in 2013. The panda loan agreement concluded in 2019, and giant pandas Bai Yun and Xiao Liwu were repatriated to China in spring 2019, in keeping with the terms of our agreement. All six of the pandas born at our zoo have returned to their homeland in China, where they continue to make us proud!
Giant pandas face big problems: Today, only over 1,800 giant pandas survive on Earth. Until 2016, they were categorized as Endangered on the International Union for Conservation of Nature Red List of Threatened Species. They are currently listed as Vulnerable, thanks to numerous conservation efforts that have helped to increase their population. However they, still face many serious threats in the wild:
Habitat destruction: Unfortunately for pandas, China’s forests have changed. The country has more than a billion people. And like us, those people have built roads, homes, cities, and farms. They mine, harvest trees, and use other natural resources. The giant panda’s range shrunk as trees were removed in logging operations and land was cleared for farming. In fact, panda-suitable habitat decreased by half between 1974 and 1985.
Populations of pandas have become small and isolated, hemmed in by cultivation. Some panda habitat has literally been encircled by farms, villages, and business sites—creating “islands” between which pandas can’t safely move without coming upon human communities or crossing dangerous highways. In some pockets, very few pandas are found. These animals are isolated and cut off from other sources of bamboo—and from other pandas.
In some areas, forest clear-cutting has completely removed all large trees—and all appropriate tree and rock den sites. Without a protective den, panda cubs are more susceptible to cold, disease, and predators.
Low reproductive rate: Pandas like to be by themselves most of the year, and they have a very short breeding season, when a male looks for a female to mate with. Females give birth to one or two cubs, which are very dependent on their mother during the first few years of life. In the wild, mother pandas care for only one of the young. In panda facilities in China, keepers help to hand raise any twin cubs; one baby is left with the mother and the keepers switch the twins every few days so each one gets care and milk directly from the mother.
Bamboo shortages: When bamboo plants reach maturity, they flower and produce seeds before the mature plant dies. The seeds grow slowly into plants large enough for pandas to eat. Giant pandas can eat 25 different types of bamboo, but they usually eat only the 4 or 5 kinds that grow in their home range. The unusual thing about bamboo is that all of the plants of one species growing in an area bloom and die at the same time. When those plants die, pandas must move to another area. This is why good panda habitat should have several different species of bamboo.
Hunting: When hunters set snares for other animals, like musk deer, the traps can kill pandas instead.
Protecting pandas: Panda protection efforts in China began back in 1957, and in 1989, the Chinese Ministry of Forestry and the World Wildlife Fund formulated a management plan for the giant panda and its habitat. It called for reducing human activities in panda habitat, managing bamboo habitat, extending the panda reserve system, and maintaining captive populations of pandas.
China's Natural Forest Conservation Program of 1998 provides protection to all remaining forests throughout the panda’s range, which covers about 5.7 million acres (2.3 million hectares).
China has set up 65 panda reserves that protect panda habitats from further development. Some are off limits to people completely, while others are shared-use areas like our national forests. Natural corridors connect some reserves to help keep panda populations together.
Today, China is currently gaining forestland. The government has started policies like the “Grain-to-Green” program, which gives grain and cash to farmers who abandon farming on steep slopes and replant these areas for natural forests and grasslands. But we’re still not sure if these newly forested areas are suitable for pandas.
It takes an international effort: Back in the 1990s, biologists didn't know if they could save pandas from extinction. Little was known of their behavior in the wild, and pandas did not reproduce well in zoos. Then, San Diego Zoo Global partnered with Chinese colleagues at panda preserves to create a conservation strategy. We developed early-detection pregnancy tests, as well as a milk formula for panda cubs that raised survival rates from zero to 100 percent. We also began using GPS technology to track pandas in the wild and learn how far they range. In 2010, we reached the milestone number of 300 pandas in zoos worldwide and breeding centers in China, which researchers believe will ensure a self-sustaining population. We are definitely boosting panda survival rates!
There is still much that we don't know about pandas. Our researchers have learned a lot about basic panda husbandry, veterinary care, and nutrition; panda reproduction; the importance of environmental enrichment; and the significance of chemical communication, or how pandas’ respond to the odors of other pandas. By gathering more than 20 years' worth of data at the San Diego Zoo, where the animals were easy to observe, we gained a better understanding of what these animals need to survive in the wild.
Working together with Chinese panda experts may help increase the number of giant pandas and ensure the future survival of the giant panda population. A giant panda milk formula created by the Zoo's nutritionist, and a hand-rearing technique developed by the Chinese called "twin swapping," have transformed the survival rate of nursery-reared panda cubs in China from 0 to 95 percent. The giant panda breeding rate at the Wolong Breeding Center in China increased dramatically following multiyear collaborations with the San Diego Zoo. Work by our scientists has advanced pregnancy diagnosis, and the captive population of pandas has reached the milestone of 300 bears, the minimum necessary to sustain genetic diversity for the next 100 years.
In 2012, we were honored to receive the Association of Zoos and Aquariums' International Conservation Award along with the Smithsonian National Zoological Park, Memphis Zoo, and Zoo Atlanta for our "Scientific Approaches to Conservation of Giant Pandas and Their Habitat."
What YOU can do to help pandas: People ask us every day how they can help save pandas. You can make a big impact by making some simple changes in your daily lifestyle, like knowing where the products you purchase come from, choosing accordingly, and buying fewer things or items with minimal packaging. You can help by choosing wood products that are certified by the Forest Stewardship Council (FSC), an independent, non-governmental, not-for-profit organization that promotes the responsible management of the world’s forests. FSC-certified forest products are from responsibly harvested and verified sources. Look for the FSC certification on bamboo products, too.
You can help us bring pandas and other species back from the brink by supporting the San Diego Zoo Global Wildlife Conservancy. Together we can save and protect wildlife around the globe.