Picture-perfect Yun Zi!

Bai Yun and Yun Zi are in the next exhibit and are both doing very well. Yun Zi is really exploring his trees in the exhibit, and often you can’t really see him clearly in the trees while he’s sleeping. Bai Yun has been pretty good about eating where our guests can see her; she even gives guests a view of her nursing the cub. We can never tell when the little guy will wake up, or what he’ll do when awake, so having a rare peek at panda motherhood is always a real treat.

Gao Gao is still off exhibit and has been doing very well. Right now he will remain there so Su Lin can stay in the front, close to our soundproof area for the hearing study (see post Panda Care).

Zhen Zhen is in the off-exhibit classroom area and has really adjusted well. She and Gao Gao sometimes communicate with each other, and Zhen Zhen is constantly in the trees trying to see the bear she’s “talking” to. Remember: the two will never have direct access to each other, as they are father and daughter. Even though Zhen Zhen isn’t reproductively mature, we wouldn’t want to breed Gao with his daughter, and we don’t know if there would be any unfriendly behavior on his part.

If you cant visit the San Diego Zoo for your perfect photo opp, do keep an eye on the Panda Cam, as we focus on Zhen Zhen and Gao Gao from time to time!

Anastasia Horning is a panda narrator at the San Diego Zoo.

Yun Zi

Our newest cub, Yun Zi, is now seven months old and spends just about all of his time either in his hammock or way up in the trees watching everyone in the queue line. I promise that this is completely normal for our little man! Yun Zi started walking and really becoming mobile later than our previous cubs, but what he lacks in experience, he makes up for in determination.

Early in the mornings he seems to come down from the trees to see what we are up to, and after getting the gist of what we are doing, he proceeds back up the trees. We often get questions about the different perches we put in the trees for the cubs, and Yun Zi has a green hammock! We try to put something in the exhibit for each cub so that they won’t always be so high up in the trees; it works for our guests, and it helps us keep an eye on them.

As Yun Zi gets older, and larger, he will, of course, outgrow his hammock and only be able to sleep on certain branches, but for the time being we love watching him climb in there to settle down for a nap!

Wild giant pandas also climb, and I’ve seen Bai Yun climb up to get a cub or help a cub out of the trees before. Sometimes, when she’s in estrus, she will climb up to see if she can see Gao Gao on the other side of the wall. So the next time you come to visit our bears, don’t be too surprised to see any of our bears climbing!

Anastasia Jonilionis is a panda narrator at the San Diego Zoo.

Note: Yun Zi will be featured the television program Today Weekend (NBC) on Saturday, March 13, between 7 and 9 a.m. A host in New York will do a live interview via satellite at our panda exhibit, focusing on Yun Zi’s new home. The show is airing live on the East Coast; we’ll see the taped version on the West Coast. Be sure to check your local listings, as times may vary!

Yun Zi

Pandas are so cute. What draws us to them? Why does the panda appeal to so many people? The answer might be neoteny—keeping a juvenile appearance into adulthood. Babies are cute. Our own young have characteristics that we humans respond to such as a big, round head, large eyes, a high forehead, and a roly-poly body. We are programmed to respond to these babyish looks. Babies just make us like them and want to care for them. It is part of our human makeup.

Human babies aren’t the only young that attract us. Puppies appeal to us. They have the short snout, big eyes, high forehead, and clumsy way of moving. The attraction we have for our own babies also endears us the young of many mammals. But then these cute babies grow up and take on adult characteristics, like the brown bear, for example. Its cubs are adorable, with all the baby looks—short snout, big eyes, and high forehead, all cute and cuddly. But they grow up, the body changes and they have a long snout, smaller appearing eyes, low forehead, muscular body, hump on the shoulders, and a business-like gait. The brown bear is a very different animal as an adult, and our reaction to it changes. We are wary and fearful of the adult bears.

Now take the panda. The cubs have all the juvenile features—big head, eyes that appear to be big, high forehead, short snout, roundish, large head, roly-poly body, and wobbly gait. Except for being larger, the adult panda isn’t much different from the cub. The snout is short, as it doesn’t need a long jaw to eat bamboo. The eyes appear large, the forehead is high, the face is broad, and adults keep the roundish, roly-poly shape. So many of us continue to respond to adult pandas as if they are still cubs; even though they are fully mature, they look like babies. This is neoteny.

Chris Tratnyek is a panda narrator at the San Diego Zoo.

Bai Yun watches Yun Zi's antics.

When she first arrived at the San Diego Zoo in 1996, Bai Yun was a young adult bear. She had an annual estrus the first three years, until daughter Hua Mei was born. During that time, we would see an increase in scent marking about two weeks prior to ovulation, and an increased restlessness would set in. Why might a female undergo such changes so far out from her breeding window?

Recall that in the wild, pandas maintain overlapping home ranges. In those home areas, the bears are generally solitary as adults. However, they are exposed to the scents of other neighboring bears that have crossed over their path days or weeks before. If a female is a few weeks out from peak receptivity, it makes sense that she would need to begin to advertise her status to any males that might be in the area. She scent marks, and a male who 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 will then likely remain closer to this female, assessing her status more frequently and keeping closer tabs on her in order to be present at the time for mating.

A younger Bai Yun has demonstrated that about a week prior to her peak, her rate of bleating begins to climb. This friendly, goat-like vocalization picks up at a time when males in the area are likely to be closer than usual, thanks to her increased scent marking. Within a few days of her peak, she increases her rate of chirping, a sharp, louder vocalization that we can often hear through the doors and windows of our building! Recent research from our collaboration with Zoo Atlanta has revealed some interesting information about these vocalizations and how they relate to male-female interactions: it appears males can use elements in the chirp to identify the precise time when a female is most fertile. Thus, when a male that has been hanging around waiting for his opportunity to mate hears his female chirping, he can assess whether or not she is ready to breed yet.

I have often wondered about Gao Gao’s ability to assess Bai Yun’s readiness for mating. Even with a truncated estrus in the last few years, and limited exposure to her scent, he seems able to pinpoint the time to breed with her. The next day, despite her willingness to breed again, he may often show no interest. Perhaps it is a change in the sound of her chirp that he is assessing and determining that it is not worth his effort to endure another breeding encounter. For a wild male, following a female closely can be an energetically costly endeavor: he risks coming into close contact with other males, and fighting may result. The process of mating itself is laborious and may take up most of a day or two, leaving him physically drained. If a female turns on the male during courtship, he could be injured. And all the effort in assessing and breeding with her detracts from his feeding schedule. Thus, it would seem that making judicious choices about when to push his luck could be advantageous to a male panda.

Why am I discussing this now, when Bai Yun is sure to experience a lull in her estrus cycle due to the fact that she is still nursing Yun Zi? Because, despite Yun Zi, we have an estrus in progress in San Diego: this time, with Su Lin. Unlike her little estrus last year, our young bear (four years old) appears to be experiencing a more adult-like, full-on estrus. She is deep into the scent-marking stage, complete with restlessness. Bleating has begun, and chirping should be on the horizon soon. This is likely her first fully fertile estrus, as females in Wolong have been bred at her age, resulting in a birth a few months later. However, Su Lin will not be breeding here, since she clearly cannot breed with her father Gao Gao. Nonetheless, this is an opportunity for the public to observe a full, lengthy behavioral estrus in a panda female, something we haven’t seen around this facility in many years!

Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.

Here’s the most recent chart comparing our panda cubs’ growth during their first 200 days:

Amy holds a panda cub at Wolong.

My panda cub encounter didn’t happen here at the Zoo, though: I was on one of our San Diego Zoo WorldWild Tours to China. As part of the trip, we went to the Wolong Giant Panda Reserve Breeding Center, where we were able to play with panda cubs for a few minutes and have our photos taken with them! Not only was it fun to see the cubs play with each other, but the way they interacted with the people in our group was also special. You could see that each panda cub had its own personality—some being feistier than others! One traveler in our group had a lifelong dream of holding a giant panda, and it touched my heart to witness his dream come true!

As director of the Zoo’s WorldWild Tours program, I’d like to let people know that we still have a few spaces left on our May 2010 trip to China, where all participants will be able to play with giant pandas cubs! Because the Wolong Breeding Center was destroyed in the 2008 earthquake, we’ll be visiting Wolong’s satellite facility in Bifengxia, which had 16 cubs born last year! At Bifengxia we’ll also have the opportunity to reunite with our beloved San Diego Zoo-born Hua Mei and Mei Sheng, as well as Tai Shan, the National Zoo’s panda “cub” that recently arrived in China. In addition, we will visit the Chengdu Panda Breeding and Research Center, where we will be able to see Mei Lan, Zoo Atlanta’s panda cub that was sent to China with Tai Shan.

Our China adventure will also include visits to Beijing, Shanghai, and Tibet—yet I know that our panda encounter will most certainly be the highlight of the trip for most of you!

Amy Parrott is the director of the San Diego Zoo’s WorldWild Tours program as well as the director of major gifts in the Zoo’s Development Department. Here’s more information on the upcoming China trip.

On this particular day, Yun Zi displayed some very comical and endearing behaviors that reminded us how purely playful and entertaining these babies are. This was a very wet day. The rain had held off most of the morning, so we had decided to give Bai Yun and Yun Zi access to the outside enclosure. However, it started to rain before we had a chance to bring the bears back inside. Little Yun Zi just experienced his first real “rain day,” and I think he liked it! How do I know this? Here’s the clue…

As the rain continued, it collected in the bottom of the moat area along the edges of the enclosure. The tall landscaped brick wall that stretches across the front of the enclosure was muddy, slippery, and very steep. Keepers only trek that wall under favorable and necessary circumstances. But on this day, Yun Zi would change the rules! Shortly after the heavy rain started, he nonchalantly made his way down the wall and planted himself in the furthest, wettest corner of the moat. This was not his normal place to “hang out,” and why he picked the rainiest day of the year to go there, we will probably never know.

Once there, though, he happily played with a tuft of grass, ignoring any and all attempts we made to entice him back up the wall. He was soaking wet, completely happy, and playing with the most simple of toys: a few green strands of muddy grass. We all laughed at the irony of that! Here we have many fancy toys for his choosing, and he would rather play with a tuft of grass.

Well, after adoring him for a while, we all concurred that someone had to go get him out of the moat. I got nominated to climb down the wall, in the rain, and retrieve this venturesome bear. This meant picking him up by the scruff (as his mother does) and caring his then 19 pounds (8.6 kilograms) up the steep, slippery wall. I was less than thrilled to do this in the rain. As I made my way down the slope, Yun Zi was watching me closely as I slowly approached him. I saw his wide eyes as I got closer, and I suddenly realized that I was wearing a bright yellow rubber rain suit that he had probably never witnessed before. It obviously made him think that I was a big, scary, yellow monster coming to get him!

I didn’t want to scare the black off of him, so I surmised that the quicker this was over with, the better for both of us. I curled my hand around the back of his neck and scruffed him. I then supported his back end with my other hand and balanced each step back up the wall. Naturally he was wiggling and trying to bite my supporting arm with his small teeth. He does have great pressure in his jaws, but not enough to cause any damage through my rain jacket. As I reached the top, I handed him off to my fellow keeper, who also struggled to contain his feisty body. Yun Zi was gently put into the tunnel leading into the den to reunite with his mom, Bai Yun. I think she was happy for the help we provided in retrieving her youngster. After a look of disapproval at the monsters, Yun Zi sauntered into his den and continued playing with bamboo sticks for some time.

It doesn’t take much to entertain a baby panda. It also doesn’t take much for us to fall in love with a baby panda.

Heidi Trowbridge is a senior keeper at the San Diego Zoo. Read her previous post, Fossa Milestones.

Zhen Zhen is in the exhibit that Bai Yun and Yun Zi were in; like Yun Zi, this enclosure was where she made her public debut two years ago. She has been relaxing and is doing very well. Zhen loves climbing, and we are curious to see what happens when she sees and smells a male (her father) on the other side of the wall.

Su Lin started walking around her exhibit constantly a few weeks ago and rarely sleeps during the day. We think that these could be early signs of estrus, and we are watching her closely and taking urine samples. We have not heard anything about when she will be going to China, and so we haven’t started working on her training for her trip. She is, however, doing a wonderful job participating in our panda hearing study, and we are very happy that she has managed to stay focused on this for us.

Bai Yun and Yun Zi are fantastic! Bai Yun has definitely gotten back into the swing of being on exhibit for the public and has even remembered where we usually hide her treats. The cub has discovered how high he can go up into the tree now, and he’s also discovered that we can’t reach him up there, and neither can Mom. He has come down to nurse, though, and he does play with Mom. And now with an even larger exhibit to run around in, he has been having a blast. Keepers will continue to go in with the cub so that he is familiar with us; this will also help condition him for when we begin to train him. Please remember that Bai and Yun Zi do have access to their bedroom, so if you don’t see them right when you come in, please be patient!

Anastasia Jonilionis is a panda narrator at the San Diego Zoo.

Den closure
Yun Zi has officially left the DEN! Keepers are no longer allowing him access to the den, and this is a decision to help him get ready to go to the main exhibit soon. Yun Zi isn’t looking for the den. In fact, he’s too busy playing, and he sleeps in his climbing structure most of the time. This is completely normal, and we are so pleased with how things have been progressing. Currently he is about 30 pounds (13.6 kilograms) and growing every day. Bai Yun is about 234 pounds (106 kilograms) and looks wonderful wearing it!

Panda training
All of our keepers are experienced in training animals, from primates to cats. All of them are qualified to train and are given equal opportunity to work panda cubs and train them. Kathy Hawk, senior keeper, leads the training with Bai Yun. The two of them have been together for almost 14 years now. Angie Fiore leads the training with Su Lin. Juli Borowski leads the training on Zhen Zhen, and everyone works with Gao Gao. Each keeper has a bear that they can focus on, but everyone is eventually working on the same behaviors with each bear.

Food is a great motivator for animals, especially if it’s a rare treat. Our pandas love apples, but something I didn’t learn until just recently is that we also train the pandas with honey. I knew they loved honey, but I had never seen it used in this way. Sure enough, Kathy will often use it to encourage Bai Yun to hold her still while a vet is conducting an ultrasound. I keep learning every day about these guys! Toys aren’t used for training, mainly because playing with a toy as a reward isn’t conducive for training.

Plants as enrichment
All of our cubs have played in the plants growing in our panda exhibits. We make sure we put plants in there that smell good and are safe to eat in case our cubs want to chew on them. Su Lin and Zhen Zhen still play with the plants that we put in their exhibits on a regular basis.

Bamboo preferences
Bai Yun doesn’t eat all of the bamboo that we offer her. In fact, we feed out about five different types of bamboo on a daily basis. Sometimes pandas go for really leafy bamboo, but other times they go for the bamboo that is a little thicker in the stalk. Their favorite type of bamboo is giant timber bamboo Bambusa oldhamii; they usually go for this first, and they get it every meal. Bamboo does have different seasons, and the pandas are the best judge of when bamboo is in season and when it’s not. If we offer a certain bamboo species and the pandas don’t go for it, that gives us a clue that it might not be in season. We give them 18 different species of bamboo throughout the year, so we always have some options. Other than bamboo, we provide our pandas with cut-up apples, yams, carrots and folivore (leaf eater) biscuits, which is a manufactured treat for them. We can tell what they’re eating by the leftovers when we clean up. This offers us information on what they will eat, when, and how much.

Anastasia Jonilionis is a panda narrator at the San Diego Zoo.

Any time an event or situation arises concerning the pandas at the San Diego Zoo, the Zoo’s Panda Team gathers together around the big conference room table upstairs at the Giant Panda Research Station and discusses the issue at hand. You may recall from previous posts that the Panda Team consists of keepers, researchers, animal care staff, and veterinarians, and everyone’s input is essential. Most of us have worked with these animals (and each other) for many years, and so it typically doesn’t take very long for us to come to an agreement about how best to proceed.

When we’re shifting bears to a new exhibit, our primary concern is always the well-being of the animal. We must first ensure that the enclosure is a safe, suitable environment for the bears and then assess how well we think they’ll adjust to this new enclosure. Bai Yun is very familiar with this exhibit space and has raised most of her cubs here, so we expect her to take it in stride. But, is the cub ready? Yun Zi’s siblings all made the transition at about this same age, and developmentally he appears to be ready.

Another important factor we have to consider is where we will shift the other bears at the facility. If Bai Yun and Yun Zi are moving to the left exhibit (currently housing Zhen Zhen), where will we move Zhen? With the recent birth of Yun Zi, we now have five pandas here at the Research Station, more than we’ve ever had before! And along with having more bears comes minor challenges in terms of housing arrangements. We have a number of enclosures; however, it’s important that we consider the relationship and proximity of the bears to one another. For instance, will it cause Zhen stress/anxiety if she is housed adjacent to Bai Yun where she can see and smell her mother? Perhaps. So we do our best to avoid this type of potential stressor and don’t house Zhen Zhen next to Bai.

Then there are still other logistics to consider, such as research needs and meeting the interests of our guests. Because Su Lin participates in our daily hearing study sessions, she will remain in the main public viewing exhibit adjacent to Bai and Yun Zi. This exhibit is the most suitable for facilitating the hearing sessions. Gao Gao will remain in an enclosure behind the scenes for the time being until we have completed our hearing study sessions with Su Lin. Once complete, we will most likely begin a rotation with Su Lin, Zhen Zhen, and Gao Gao between the off-exhibit areas and the main public viewing exhibits. This will provide some variety for the bears as well as allow guests the opportunity to see different bears over time. We know that each panda has his/her own group of fans! So far, the bears are handling the changes very well, and we hope to complete the transition in the next few days.

So, this is just a little insight into the decision-making process that goes into a “seemingly” simple transition of a few bears into a new enclosure. There are a lot of factors to consider, and we always do our best to ensure the well-being of our bears.

Pamela Crowe is a research technician for the San Diego Zoo’s Institute for Conservation Research.

Watch video of Yun Zi’s first day in his new exhibit!

Yun Zi in his new enclosure

Our morning began with getting their exhibit cleaned and prepared for Yun Zi, making sure that there was nothing that he could possibly get hurt on or stuck in. We then got the back classroom area, which had been used by Bai Yun and Yun Zi each morning, ready for big sister Zhen Zhen’s move. On her way through the tunnel system to the classroom, Zhen came across a scent that was quite familiar: her mother. Right as Zhen walked by Bai Yun’s back bedroom, where Mom and cub have been residing for the past six months, she became very curious, and it took a little more encouragement on our part to get her past that area. Eventually Zhen Zhen made it to the classroom exhibit door, and she seemed very excited to be in a new area.

After Zhen Zhen was secure in the classroom, we began the move with Bai Yun and Yun Zi. Bai Yun has always been very easy to move, and she was eager to see where she was being directed to. She began walking down the tunnel, and sure enough, little Yun Zi did a wonderful job of following his mother.

We are so pleased with how everything went this morning, but we do have some things that everyone needs to be aware of. Bai Yun and Yun Zi will have access to the bedroom attached to their new exhibit space, and later in the day, access to their bedroom in the back. So at this time we are not promising a view of the cub; in fact, there is a chance that there will be days when Yun Zi stays inside the bedroom. This is something that we have gone through with other cubs, and we expect to get through this transition with little difficulty and a short period of time!

Anastasia Jonilionis is a panda narrator at the San Diego Zoo.