The Wanderer
Posted at 12:03 pm November 15, 2005 by Suzanne Hall
I have noticed that lately Gao Gao (pictured) has been a bit more active. He has been like this in the late summer and early fall for a few years now. He spends time wandering about his enclosures, even when good food is present to occupy his time. We didn’t see this same pattern with Shi Shi, who was with us for several years. What is going on here?
You may know that female pandas come into estrus once a year in the spring for breeding, which occurs during a short window of 24 to 72 hours. If all goes well, the female will become pregnant and will not mate again for another two years as she raises her cub. But what if she doesn’t get pregnant?
Before Gao Gao came to us, we didn’t have much breeding success. Hua Mei, the success story everyone has heard about, was the result of artificial insemination (AI). What you may not have heard about was the many breeding seasons in which we hoped for a mating that didn’t occur, and the AI’s that were unsuccessful. As a result, come fall of many years, Bai Yun didn’t have a cub to raise.
Bai Yun developed a fairly typical pattern in the fall in which her energy levels seemed to increase. She began pacing about her enclosures, which alarmed us at first. Why was she pacing? Was she unhappy? Interestingly, despite our best efforts, we weren’t able to stop this behavior. Predictably, we saw it each year. We had heard reports of some females having a “fall estrus.” Perhaps this was what Bai Yun was experiencing. During spring estrus, Bai Yun wanders a lot and scent marks a good deal. This fall behavior pattern seemed like a muted version of her spring activity.
Not long ago, a female at a Japanese zoo had a fall estrus, and their staff opted to put the male in with her…and they bred! Even more surprising to us all was that she then went on to have offspring as a result of that breeding. So the fall estrus appears to be a real, physiological phenomenon and not just a fluke we observed in Bai Yun.
That brings me back to Gao Gao. Why is he wandering? Although he doesn’t experience “estrus,” he certainly undergoes some changes in the spring breeding season: most notably, his testes increase in size. Perhaps in the fall he experiences some sort of physiological shift too, one that would prepare him for a possible encounter with a female who is experiencing a fall estrus? We never saw this kind of pattern with Shi Shi, but then again, Shi Shi never showed us much drive to breed. Gao Gao undoubtedly is more motivated in this arena.
There is no hope that we will find out soon if a fall mating is possible between Gao Gao and Bai Yun. Our female is very busy raising Su Lin, and we would never jeopardize the health of this cub in order to test this theory. However, if some spring breeding season should pass without a pregnancy in Bai Yun, we can wonder if perhaps all is not lost. And if the opportunity presents itself, perhaps….
Suzanne Hall is the panda research technician for the San Diego Zoo’s Office of Giant Panda Conservation.
You can follow any responses to this entry through the RSS 2.0 feed. Comments are currently closed. Pinging is not allowed.
November 15th, 2005 at 12:09 pm
In Bai Yun’s case, wouldn’t she have to stop nursing before she can experience an estrus?
November 15th, 2005 at 12:17 pm
Is there an age or behavior in the female panda that shows they can no longer breed?
November 15th, 2005 at 12:30 pm
Gao Gao is a true stud!
November 15th, 2005 at 12:51 pm
Gao Gao – you’re a handsome devil!
I think Gao is one of the most sweet-natured bears ever…he’s just so carefree and content. Hugs to you, our bamboo-munching machine! 
November 15th, 2005 at 1:06 pm
Yup. He’s on a higher level. (” Gao” doesn’t just mean tall. It can also mean a higher level or station. Or maybe he was named that because he liked to ” stand” .)
November 15th, 2005 at 1:12 pm
Oh my goodness! I just saw Su Lin outside with momma!
What a joy to see the little cutie exploring…she must be overwhelmed by all the sights and sounds!
November 15th, 2005 at 1:18 pm
I can’t get over that I just saw Su Lin outside with momma!! How cute they both looked!
November 15th, 2005 at 1:20 pm
Thank you to all of you who allow me and everyone else to share in the wonder of the giant pandas. I get so much pleasure out of keeping up with the whole group on a daily basis. About the fall mating, it is great to know that not all is lost if a spring mating doesn’t result in a pregnancy. Again thank you!!!
November 15th, 2005 at 1:33 pm
Saw Bai Yun take Su Lin outside. She’s growing so fast.
November 15th, 2005 at 1:57 pm
How wonderful! Bai Yun and Su Lin are doing exactly what Suzanne predicted in her ” Lair” blog. It’s great that their behavior is following that of the wild Pandas so closely, and speaks very well of both Bai Yun’s mothering and of the Panda team that works so hard to make their lives as natural as possible. Can’t thank you enough for all that I’m seeing and learning. What joy!
November 15th, 2005 at 2:09 pm
What a milestone, to watch Mom nurse her baby outdoors. Nature is wonderful!
November 15th, 2005 at 2:24 pm
Panda lover (#1),
Yes, she would have to stop nursing. That’s why we won’t be seeing a fall estrus soon. To do so, we’d have to take the cub away, which we aren’t willing to do.
November 15th, 2005 at 2:25 pm
Elizabeth (#2),
Females in Wolong have bred up to age 17-18. They come into estrus beyond that but no pregnancies occur.
November 15th, 2005 at 2:35 pm
I just ” checked in” and there was Su Lin out with Mama!!! Finally, the day has arrived for a field trip outside the Birthing Den. Bai Yun is being so protective and sweet. She is sitting as to shelter Su Lin and rest her upper body weight on a tree branch. Her facial expressions are amazing. Seeing the ears checking for all the different sounds……Priceless and so loving! Thank you for such a wonderful treat on today’s Panda Cam. Window from the heart.
November 15th, 2005 at 3:01 pm
I happened to ” check in” and caught them both together….outside.. Now would be a good time to pull up the old info and let us know at what age she took Hua Mei and Mei Sheng out. Watching the DC cub Tai Sheng and his protective mother, one has to laugh remembering our own mothering days..We were on pins and needles and boiled everything in sight for the first one, then with all subsequent kids, we just let them eat dirt.
November 15th, 2005 at 3:14 pm
Thank you for letting us see Bai Yun take her daughter out to the ” big yard.” It’s the first time that I’ve seen them there.
November 15th, 2005 at 3:23 pm
Suzanne, also in Japan, the same panda gave birth to twin cubs in 2003. Both cubs were lovely nurtured by their mom. The panda mum held both pandas in both ” arms,” very touching! All the zoo staff needed to do was to give twin cubs extra milk when they were 5 months old, since mom’s milk was not enough to raise two little guys then. I feel Bai Yun could do the same job if in case she has twins.
November 15th, 2005 at 4:04 pm
Eugena,
Yes, the Japan female in question did a heroic job in raising twins all by herself. It is important to note, however, that she is an extreme exception. Several pandas in Wolong have attempted to raise their twins on their own and ultimately give up trying due to the difficulty of managing more than one cub. Bai Yun is an excellent mother, but no one here would be disappointed in her if she couldn’t rear twins without our help.
November 15th, 2005 at 7:07 pm
I’m so disappointed that I missed the big outing with Su Lin! We knew the day had to be getting close.
Great info on reproducing, Suzanne. It never ceases to amaze me the amount of wonderful things you have to tell us about these incredible animals. It’s obvious that you are learning so much about them yet after all these years of tending to them!
November 15th, 2005 at 10:09 pm
This is exciting news about a fall estrus. I’m sure you share this info with DC, Memphis and Atlanta as well as Wolong. Maybe the zoos in Memphis and Atlanta can be on the alert for signs and we can have additional babies in late winter or early spring? This is fantastic news because if wild pandas do have a fall estrus then maybe there are actually more pandas in the wild!! I really do hope so….
November 15th, 2005 at 11:08 pm
Thanks Suzanne for such great insights..always look forward to reading your blogs. Do you think there is a good chance of a spring estrus? I am thinking that by that time the cub would be weaned.
November 16th, 2005 at 4:53 am
Thanks for the interesting info Suzanne. This gives us even more hope for the survival of these beautiful animals. Thanks for all your wonderful and informative updates. Give Su a big hug for me.
Jeannie
November 16th, 2005 at 7:16 am
On the National Zoo site, they were stating the same thing about Tian Tian as he was restless and scent marking.
November 16th, 2005 at 8:51 am
My first baby panda was Hua Mei. I fell in love. Bai Yun was a natural and the ” hands off” approach San Diego employs is the perfect environment for these pandas to flourish as naturally as possible. Bai Yun was a pro from the get go. She let things happen naturally. But she just didn’t seem to sweat Hua Mei or the other two babies like a new mother normally would. Mei Xiang appears to be younger, at least in my mind, because she seems to want to play with Tai Shan whereas Bai has let the babies play when they want to play and sleep when they want to sleep.
What a joy it is to watch these two VERY different mothers nurture VERY different babies. And what a wonderful gift both zoos have given to all of us by allowing us to watch nature in progress.
Thank you
November 16th, 2005 at 5:21 pm
Suzanne, did you already read about panda females in China having fall estrus too ? perhaps fall estrus is due to a warmer climate and occurs only in panda females living in warmer countries like California or Japan ? a warm climate is like a longer spring allowing them to have another estrus and to give birth later in the year… in China panda mothers usually give birth in july-august-september because it is summer and the fragile cubs can survive… it is easier to give birth to a fragile panda cub in december in California than in cold mountains of China. my english is poor, I hope you understand what I mean. congratulations to you all for the great work with the pandas.