male panda


Big Guy on the Block

Gao Gao is fueling up for breeding season. Little does he know....

Gao Gao is fueling up for breeding season. Little does he know….

As some San Diego Zoo guests are finding out, Gao Gao is the only panda out for viewing in the main exhibit currently (Bai Yun and her cub, Xiao Liwu continue to charm guests in the north exhibit until noon each day). As construction workers continue building Yun Zi’s artificial tree (which looks great so far!), Gao Gao has been entertaining us with his usual eating and sleeping, and a little extra movement right now.

Many of you know that Bai Yun would typically begin showing some hormonal behaviors as early as March for breeding season, and Gao Gao is letting us know that he is ready. He is currently eating more and gaining weight to show off to that gorgeous female he sees once a year. Of course he will not be breeding this year as Bai Yun is with a cub and not cycling. So the big question everyone’s been asking lately is, “What will Gao Gao do?” This year Gao Gao will just have to cope, and soon he’ll realize that he doesn’t smell a female in estrus.

As for next year’s breeding opportunities, we can’t say. To the best of our knowledge there hasn’t been a female panda to give birth over the age of 21, and Bai Yun will be 22 this coming September. We have observed an older male, Shi Shi, but watching a female for her entire breeding life has taught us so much about what is normal for Bai Yun. She is, after all, a big part of Gao Gao’s success as a breeding male—she is responsive and an amazing mother to her offspring.

Come see us soon, but do not be upset if you see Yun Zi off exhibit as his tree is being constructed!

Anastasia Horning is a panda narrator at the San Diego Zoo. Read her previous post, Pandas: The Big Boys.


Gao Gao and His Bread

Gao Gao

Here at the San Diego Zoo, we are dedicated to making sure our animals have the best quality of life that we can offer them, with great keepers and vets. Some of our animals do begin to show their age in different ways as they get older, be it teeth, arthritis, cataracts, or even organ failure. For one particular panda at the Zoo, dental care has become a major upkeep. I’m speaking, of course, of Gao Gao, our fabulous adult male panda.

Gao Gao’s exact age is unknown, but we think he could be in his early 20s. In the wild, these animals would typically live 14 to 20 years, and a huge factor contributing to their decline is their teeth, which often wear down to the point that the panda is unable to feed itself anymore. We have run into similar issues with Gao Gao: a root canal has been done on his front canine tooth, and a bridge was recently done for him as well. These procedures are to help keep him comfortable, but we have had to greatly modify his diet to also assist with his eating habits. Gao Gao only gets thin pieces of bamboo to help alleviate daily stress on his teeth, and he gets more leaf eater biscuits, apples, carrots, and yams. He also gets a special bread made of bamboo that has been ground down and mixed with the biscuits. This gives him something a little different, and it has helped keep his weight up.

Gao Gao is currently 175 pounds (79 kilograms) and going strong. He has been spending quite a bit of time resting and taking it easy in the shade, but once he’s been given fresh food for lunch, he’s out there eating for over two hours on some days. As Gao Gao’s needschange, our staff is ready to modify whatever he may need to ensure that he has the best quality of life and is as comfortable as possible!

Anastasia Horning is a panda narrator at the San Diego Zoo. Read her previous post, Bai Yun: Enjoying Time Off.


Pandas: Unraveling a Mystery

A wild panda rests in a tree in China's Foping Nature Reserve.

A male panda sits, hour upon hour, lazily grabbing bamboo stems, pulling them to his mouth, where powerful jaws and crushing teeth make short work of it. A few hours later, it comes out the other end, changed little by the passage through his intestines. After a few days of this routine, intermittently sleeping and eating in a circumscribed area, the panda rouses and begins heading up the slope. He pushes through the dense bamboo, slow and shuffling but somehow graceful.

Upon reaching the ridge, he enters a different world—the dense bamboo gives way to open understory beneath a towering canopy of ancient spruce and fir trees. It’s a pleasant enough place for a picnic, but for pandas, the picnicking is better below in the valley. This panda has come here not to eat but to communicate: this ridge is like a community bulletin board, and scent messages are posted on these ancient trees.

Every move a panda makes is calculated to conserve energy. Even his placement of scent marks is efficient. He walks past a smooth-barked tree in favor of one with rough bark, lifts his tail, and rubs his gland in a circular motion. His scent is spread across little crevices that increase the surface area, maximizing the “odor field” of his scent. He approaches another tree and sprays urine over the trunk while doing a handstand.

He chooses a large tree, lest he miss his target and let the golden message fall to the ground. He needs his urine mark to be up high; it will waft farther through the air where it is more likely to capture the attention of a passing panda. The height of his mark also conveys his status; other pandas will read “dominant male,” at least in this neck of the woods. For a urine mark, he chooses a tree with ultra-rough textured bark that captures the urine, keeps it from trickling down the trunk, and perhaps keeps it from washing off easily in the frequent rainfall characteristic of these Chinese mountains.

Other pandas will be able to read his urine mark for about two weeks, but the mark from his gland will last four months! This way he does not to have to climb back up to the ridge again for a few weeks. He ambles further down the ridge path, stopping to sniff the marks left by pandas that have come before him. This one, his nose tells him, comes from a young male that came here and left his scent several weeks ago; it represents no threat.

The next one, however, came from another large dominant male. He has tangled with him before, he remembers, and two years ago this male bested him in a long, drawn-out contest for access to a fertile female. The next mark encountered really gets his attention: it’s from that same female, and she is again nearing her fertile period. After leaving the scent ridge, he will expand his range in search of signs of this female. She will be marking frequently now, and several males will catch her scent and track her down. There’s bound to be trouble.

Such is the life of a giant panda. I can be relatively certain about my scenario only because of years of study, working with many partners and colleagues at breeding centers in China and wild pandas at the Foping Nature Reserve. Our collective effort allows me to paint this picture and begin to unravel the mystery of this rare and difficult-to-study species.

We now know, for example, that pandas require very different habitats for communicating with one another than what they need for foraging. We must work to protect all the panda’s habitat, including the palette upon which they paint their scent messages.

Ron Swaisgood is the director of Applied Animal Ecology, San Diego Zoo Institute for Conservation Research and co-head of the San Diego Zoo’s Panda Team. Read his previous post, Cocha Cashu: Exploring Uncharted Territory.

Author’s note: The story described here is derived from years of collaborative research with many partners, most prominently Professor Wei Fuwen’s Key Laboratory for Ecology and Conservation Biology at the Institute of Zoology at the Chinese Academy of Science and the China Conservation and Research Center for the Giant Panda.

Photos courtesy of the Institute of Zoology, Chinese Academy of Science.

Visit San Diego Zoo Global’s Wildlife Conservancy website for photos, videos, and great stories of our work to help wildlife near and far.


Pandas: The Nose Knows

Yun Zi has his own communication style.

It’s hard to find someone who is not charmed by the entertaining antics of a roly-poly panda bear. Being one of only four zoos in the United States to exhibit pandas, the San Diego Zoo certainly sees its fair share of panda fans. Guests love watching the cute black-and-white bears munch on bamboo, roll through bark chips, or do handstands against a tree. Although these behaviors are enthralling and endearing, scientists believe they may also be serving as an essential means of communication between the bears.

The most distinguishing feature of a panda is their black-and-white fur. The fur keeps them warm during the snowy mountainous winters of Sichuan, and scientists believe that the black-and-white coat may provide some camouflage in the shadowy bamboo forests where pandas are found. Because these bears are solitary, and are not necessarily easy to see in their native habitat, pandas use scent marking as a means of communication. Instead of sending e-mails or posting fliers, pandas will “post” their personal information on a nearby stump, rock, or tree. This is done by lifting their stubby, white tails and rubbing their scent gland on the chosen item to broadcast vital information. A male panda, such as the San Diego Zoo’s very own Gao Gao, may even do a handstand to urinate or rub his scent gland high on a tree to advertise his size and virility. This message communicates to other passing males and females that he is strong, mature, and healthy. Other males may think twice about crossing paths with this formidable opponent, and it may help females become acquainted with the smell of Mr. Big, Strong, and Healthy. This could bolster the male’s chances of breeding with females in the future.

Communication works best when it’s a two-way street, so female pandas also do their fair share of scent-marking. A female panda’s personal scent changes during her estrus cycle, and male pandas can identify the changes in her scent, some of which are related to the changes in her hormone levels. Let’s picture a male panda roaming through the shadowy forest, looking for a female. His best chance is to sniff her out because the female will have spent some time using the scent gland under her tail to broadcast her olfactory message. Once the male actually locates his potential mate, he may keep tabs on her and check in periodically to see if she’s close to estrus. When he thinks the timing is right, he will approach, although he may not be the only potential suitor vying for the female’s attention. Males may compete to be her mate, but even the winner may not be chosen to couple with the female. It seems that sometimes the ladies have a preference about which male becomes the father to their cubs. Perhaps in the panda species the nice guy actually wins?

Although it does not seem related to reproduction, female pandas have been observed rolling and rubbing novel scents such as flowers and bark chips on their backs, much like applying perfume. The San Diego Zoo’s female, Bai Yun, particularly enjoys rolling in cinnamon and nutmeg. She then proceeds to spend her day cruising around smelling like a giant black-and-white pumpkin pie. There is yet no known reason why pandas do this, but it makes one wonder if pandas sometimes fragrance themselves just because they enjoy the aroma.

It is interesting to note how much information can be passed between pandas without a spoken word. Detailed information is communicated using only local, renewable, natural resources. In essence, pandas have found an extremely efficient means of communication without creating a carbon footprint. Could humans create a method of communication that is so effective, yet Earth-friendly?

This post highlights a few examples of what makes pandas such an amazing species and offers an example of biomimicry. The field of biomimicry involves learning about nature, learning from nature, and being inspired by nature. If you would like to learn more about the Zoo’s efforts in biomimicry, please visit our recently renovated Biomimicry section.

Sunni Robertson is a lead educator at the San Diego Zoo.


Bai Yun and the Boys

“It’s quiet…too quiet…” we kept saying, for the first couple of weeks, anyway. Since Su Lin and Zhen Zhen left for China in late September, it has been very quiet at the San Diego Zoo’s Giant Panda Research Station. The girls’ departure was bittersweet for all of us. Saying goodbye to these bears that we’ve cared for since their birth was not easy. Of course, we know that their move to China is an essential part of the survival of the giant panda species. To aid in the survival of the species is why we all chose to work with pandas in the first place. Nonetheless, saying goodbye to the girls was difficult. At first, we keepers didn’t quite know what to do with ourselves. We got a lot of extra cleaning done, finished some projects that we kept meaning to get to, and basically drove each other crazy. In hindsight, we should have enjoyed the down time. We should have known better.

Down time never lasts long in the zoo world. Things are always changing. Panda keepers at the San Diego Zoo take care of more than just pandas. In fact, in recent weeks we’ve gained a few more animals to take care of. Our Siberian musk deer and white tufted deer herds changed exhibits and grew in numbers, and we resumed the care of three Indian crested porcupines. Of course, let’s not forget the three bears that still reside at the station; Bai Yun, Gao Gao, and Yun Zi are always giving us something to do!

Bai Yun is, as always, the queen of the Panda Station, a fact that she constantly needs to instill in her young cub. As Yun Zi begins to consume more bamboo and other solid foods, food competition with his mother becomes more apparent. It’s fun to watch Yun Zi sneak between his mother’s legs or under her belly to steal a piece of her bamboo. Most of the time, she allows him to pull a leafy piece of bamboo onto the cave or to his hammock so that they can both eat in peace. As he grows, though, he’s becoming more interested in the culm pieces of bamboo instead of the leafy pieces, which Bai Yun is less tolerant of sharing. She’s been pushing him away and will sometimes take the food directly from his mouth. This leads us to the next change that will be happening shortly: weaning!

Although we’re a few months off yet from weaning Yun Zi from his mother, preparations have been happening for a while. Yun Zi is now 65 pounds (29.8 kilograms)! It seems like it was just yesterday that he had the appearance of a hairless lab rat. At a whopping 65 pounds, his keepers can no longer safely lift him to remove him from the exhibit. Because his idea of “helping” us is stealing our rakes, ripping holes in our trash bags, and biting our shoes, we’ve been busy teaching him to shift into the bedroom area while we service his exhibit.

Teaching him to shift led to teaching him to follow us through the transport tunnels to other areas of the research center. In preparation for his vaccinations, we spent several training sessions asking Yun Zi to follow us to the squeeze crate. He shifted beautifully up to the squeeze crate after just a few tries, but getting him back down to the exhibit was a feat! Bringing him out of his exhibit exposed Yun Zi to all sorts of new sights, sounds, and experiences. Watching him explore the tunnel while he completely ignored his mother and his keepers reminded us just how independent little Yun Zi is becoming (believe me; it was much easier when he just followed Bai everywhere!). Training him early on to follow us around, though, will be beneficial when it’s time to wean.

Gao Gao has been welcomed back to the main viewing area since Su Lin and Zhen Zhen’s departure, and he seems to be loving the exhibit! And why wouldn’t he? He gets to sleep on top of the artificial den, laze around in the pond when it’s hot, and people-watch while he munches endlessly on his bamboo. Since he’s been moved downstairs, though, he hasn’t been able to spend all of his time lounging around. Both Gao Gao and Bai Yun are being trained to participate in the panda hearing study (see post One More Thing before They Go). http://blogs.sandiegozoo.org/blog/2010/08/12/one-more-thing-before-they-go/  Bai Yun, of course, has needed very few reminders of how the hearing study sessions work. She’s been picking up the behaviors like a pro. Our Gao, on the other hand, has needed a bit more attention. He hasn’t had too much trouble remembering to touch his nose to the target when he hears a tone, but getting him to sit still for the maximum of 10 seconds before a tone might be played—wow! You’d think that’s the most difficult thing he’s ever had to do in his life. Patience is not one of Gao’s stronger traits.

All is well in Pandaland. We’ve heard that the girls are doing well in their new home, too. Some of our staff is well acquainted with their new keeper, and we’re glad to know they’re in good hands. I’m sure they’d also be glad to know that their family members are keeping their old keepers plenty busy back in San Diego.

Juli Borwoski is a senior keeper at the San Diego Zoo. Read her previous post, Den Cleaning.