Panda Pregnancies 101

Posted at 8:51 am November 8, 2010 by Barbara Durrant

Our director of the reproductive physiology has provided some more answers to questions regarding panda pregnancies.

We are so pleased to learn of the birth of Zoo Atlanta’s newest panda cub. The 3-D pictures of Lun Lun’s cub in utero certainly were amazing. This advanced imaging is normally used in humans to detect skeletal and cardiovascular defects, but has become popular among human parents-to-be for getting a “sneak peek” at what their baby may look like at birth. Should our own Bai Yun become pregnant again, it is possible that we will also invite a local expert to help us obtain 3-D images of a cub (or cubs), as we do not currently own equipment that allows us to capture these images.  In our case, 3-D imaging would not replace our routine 2-D ultrasound scanning to monitor the growth of Bai Yun’s fetus(es).

In addition to the standard tests our veterinarians and researchers would run to monitor Bai Yun’s health and pregnancy status after breeding, we will certainly measure her ceruloplasmin levels. This protein may give us information about the presence of a fetus before our standard tests are able to detect a pregnancy.

We have seen with thermal imaging and ultrasound that many giant panda pregnancies are lost during gestation. There are a few reasons that a fetus might be reabsorbed. Fetal defect or death, uterine disease, maternal disease, or hormonal disruption of a pregnancy could all cause a fetus to be reabsorbed. This phenomenon is widely reported in mammals, including humans. During the process of reabsorption, the fetus breaks down in the uterus and through natural processes is eliminated. In Bai Yun’s pregnancies, when a twin died our veterinarians did a follow-up ultrasound to verify that no fetal tissues remained in the uterus.

Our vets and animal care staff continually monitor Bai Yun’s health, so we can rule out maternal or uterine disease as a factor in fetal resorption. In our endocrine lab we monitor Bai Yun’s hormone levels and know that there were no deviations from the normal pregnancy profile. With ultrasound we have been able to see fetuses begin to break down and sometimes disappear completely. But the exact cause of fetal death in giant pandas is still a mystery. Through our work with ultrasound and thermal imaging, we suspect that Bai Yun routinely conceives multiple fetuses, then reduces that number to one through a process called “prenatal litter pruning.” Because it is very rare that a giant panda mother raises more than one cub, there may be a mechanism within the uterus that reduces a multiple pregnancy to a singleton before birth about 50 percent of the time.

There is no evidence that twinning is more common following artificial insemination (AI). With our own Bai Yun, we know she was pregnant with twins (or even triplets in one case) following natural breeding.  The fact that she gave birth to a single offspring was not related to the method of insemination (artificial or natural). Some giant panda researcher believe that artificial insemination following natural breeding will increase the incidence of twins, but there are no data to support this belief. Regardless of our ever-improving AI techniques and timing, it is not a substitute for natural breeding! The male giant panda always knows the right time for insemination, and fresh, unprocessed sperm is always the most fertile.

Barbara Durrant is the director of the Reproductive Physiology Division at the San Diego Zoo Institute for Conservation Research. Read her previous post, Panda Pregnancy Tests.

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48 Responses to “Panda Pregnancies 101”

  1. Toni says:

    Neat info. Yes. Double screening the SD panda cam with the ZA panda cam is a fun one. Lun seems to be a great mom.

    The 3D images of a baby is really a work of art.

    I’ve been to the SD Zoo a few times and think it’s the absolute best. Will make it to ATL once the cub is older. : )

  2. Debbie says:

    Barbara, this is an absolutely fabulous blog. I have always wondered about the reabsorption process, but I did not know that you could see it happening in the womb, very interesting and sad. I appreciate your taking the time to explain this, thank you. Now let’s all hope when the time is right that Queen Bai will have one more cubbie herself. How could we go wrong with a stud muffin like Gao!!!!!

  3. Bobbie Wood says:

    Thank you Barbara for all the information learned about panda pregnancies. We all appreciate the information which you all at the SDZ provide us.

  4. Danielle, NY says:

    Barbara, thanks you so much for such an interesting blog. Triplets!! I had never even heard that pandas could have triplets, but I suspect that in the cases of pandas expecting triplets, at least one fetus must be reabsorbed. I also wonder if stress might play a role in that process. Of the four pregnant pandas that were released in semi-wilderness, only Cao Cao gave birth to a cub. Of course they were probably not sure that the pandas were indeed pregnant.

  5. PandaLover says:

    Thank you, Barbara! Bai Yun was pregnant at one time with triplets??? Can you tell us more…what year? Do you know if a panda has ever delivered more than 2 cubs? Thank you for the informative post!

  6. PandaLover says:

    It would be cool to see 2 cubs in utero! I hope someone (company) will donate and offer SDZ the chance to use their equipment next year with Bai Yun to obtain 3D images!

  7. lu says:

    Thank you for all the info, very interesting. Why does China seperate the small cubs from it mother? I saw a
    film on twins, very young were in a incuberter just getting there color and they were feeding them and
    etc? I sure hope that Bai Yun can have another cub.
    See you in three weeks, can hardly wait.

    Moderator’s note: The Chinese remove the cubs from their mothers so young in order to induce the mother to have an estrus the next spring. This generally results in more cubs born per year.

  8. Kristi in Austin, TX says:

    WOW! Thanks for this interesting blog, Barbara! I can’t wait to see a 3-D image of Bai’s next cub (if she chooses to have one, of course!).

  9. Kathy in CT says:

    I love these blogs- there never seems to be a moment that I am not learning something new! I came upon this site when students and I were looking for more info on pandas- and there he was, wee baby Yunnie… What a treat it is to stay so current on the topics the Panda Canyon team so eloquently writes for us. On another note, Lun Lun is so delightfully precious with her tiny little wonder. I am in awe of the care and comfort she provides. Do Bai and Yun know (hear/see) what is going on in the enclosure that is being upgraded for them?

    Moderator’s note: I’m sure they know that something different is happening

  10. Lynn (Scotland UK) says:

    What an interesting blog re Panda pregnancies. I do hope Bai Yun can manage one more.
    Just wondered, do the Pandas show any confusion with the change of the clocks, especially with feeding time? Also, thought I might mention that the PandaCam clock may not be showing the correct time.

    Moderator’s note: Thank you for reminding us about the Panda Cam clock.

  11. Dianna from Ohio says:

    Thanks Barbara for an interesting post. Is there any plans to use the 3D imaging for Chinook?

    Moderator’s note: Not at this time.

  12. inparadise says:

    Could Bai’s multiple fetuses be caused by she and Gao mating multiple times during her estrus?

  13. sydney nelson says:

    your panda camera has been fuzzy, out of focus for the past few days.

    Moderator’s note: Yes, we have been having some technical issues with Panda Cam and are working to resolve them.

  14. Karen says:

    Thank you for informing us about Panda Pregnancies. I sure hope Bai Yun can have 1 more bundle of joy.

  15. Lucilla in Singapore says:

    WOW, a panda’s reproductive process sounds complex. Just pray that Bai and Gao will be blessed with one more cubby. Also the various American born subkidults will bring more joy in the years to come with their offsprings. Sad to hear and read who think it is a waste of time and resources to preserve these gorgeous animals. When I see photos of Yun Zi and Bai Yun, I think the pandas have so much to teach us actually.

    As I am not American, I do not knwo when Thanksgiving is but HAPPY THANKSGIVING to all Panda fans.

    Moderator’s note: Thank you, Lucilla! We celebrate Thanksgiving in the U.S. on the fourth Thursday of November; this year it will be on November 25.

  16. Chari Mercier says:

    Hi! I also read your article about panda pregnancies, and it was very interesting. I’m glad that you are thinking about borrowing and using a 3D/4D ultrasound machine on Bai Yun if and when she does show signs and behavior of being pregnant next year after Yunnie gets weaned. Those 4D ultrasound pics of Lun’s baby panda are awesome! I know that you always remind us about this in that panda pregnancies are very complicated and unpredictable, and there is so much more to learn about female panda physiology, reproduction, and pregnancies. Momma pandas can be finicky, can they?

    About momma pandas, been getting on the AZ pandacam off and on when I can. Did get to it today but couldn’t see anything, but the AZ panda keepers are doing a great job keeping us informed about Lun and her cub with their latest update today, 11/8. Lun has been given some water in a bowl by the bars of her den so that she can get a drink of water without putting her cub down. Lun’s very adept with that balancing act! Lately, she’s been given a little bit of sugar cane to munch on, and today, she put her cub down on the nest and left the den for about a minute or less to inspect some bamboo that was just outside the den door, but didn’t eat any of it. She went right back to her cub! Smart momma!! Eventually, she will start leaving her cub once she feels that her cub is warm and safe to go and eat some boo. I am still hoping that the AZ people will extend those pandacam hours. I did try to get on the cam today before leaving to go to the store, and it was on WAITING! That meant that there were alot of pandafans watching the cam and trying to get on the cam to see Lun Lun! Patience, I remend myself! Will try to get on the cam a little earlier tomorrow.

    I did get on the SDZ pandacam, and I was watching Bai and Yunnie having a wrestling match! This was at around 7pm or so tonite. Hope everyone got their clocks set back an hour over the weekend!

    Well, gonna go for now. Will be back later!

    Chari Mercier 🙂

    St. Pete, FL

  17. Danielle, NY says:

    #47 pandafan-north from previous blog – Thank you so much for the video of Mei Lan. I truly envy you for having the opportunity to watch Mei Lan for one hour!!! When she first arrived, I read that she didn’t venture very much in her enclosure, which I understood is fairly large. Does she now go all over her enclosure?

  18. Lucilla in Singapore says:

    ‘Form of a crane,’ breathes Yun Zi as he stands on one feetsie and spreads out his front feetsies like wings. He then moves into, ‘couching tiger’ pose while sweat pours down his face.

    ‘Keep going, young Master Gao! Lift that paw higher!’ intoned his Panda Wu Gong Master, Gao Gao.

    ‘Yes, master,’ replied Yun Zi as he adopts the snake stance. His blue exercise outfit was soaked. His padded tai qi shoes were well worn.

    During the rest break as he was chomping on his steamed bamboo bun, Xi Lan and Princess Ping came to join him. Being older, they were in the more advanced class. They sat next to him and brought out their water bottles and steamed buns to eat.

    ‘Whew, I am exhausted!’ declared Princess Ping, ‘but I love the moves I learnt today!’

    ‘What did you guys learn?’ asked Yunnie, eyes wide with excitement.

    ‘I used the bamboo spear and I learnt the first 3 movements using that and the shield,’ said Ping matter of factly.

    ‘I got to use the jade lance and tried to attack an enemy, a straw one but it was fun,,,,hiyak, eeeeyak!’ exclaimed Xi Lan as he pranced and jumped demonstrating his moves.

    ‘Wowie! I cant wait till I can do that!’ exclaimed Yun Zi.

    ‘Do what, young man?’ asked Master Gao Gao who was not only the kung fu master but his papa as well.

    ‘Papa, I want to get good enough soon so that I can start weapons training!’ said Yun Zi with a grin.

    ‘And why would my boy want that?’

    ‘So I can rid the valley of bad people and animals who want to get rid of us,’ replied his son earnestly.

    ‘Listen here, cubbies, kung fu is for self defense. We use it to protect ourselves not to attack people or animals. We do not go seeking to take a life. All life is precious. Mine was spared many moons ago. They could have killed me but I escaped with just a torn ear. Understand?’ demanded Gao Gao.

    ‘Yes, sir!’said the trio in unison.

    ‘Good, now let me tell you a story of ancient times,’ said Gao Gao grinning. As he settled down, the cubbles came and sat round him for they loved their master’s stories. Even the very young ones who were still in play school; the Madrid twins, Atlantic Hope, Xiang Xiang son of Hua Zhua Ba and Yun Zi’s baby brother sat still as they listened to another thrilling story of long ago China when the Kingdom of Panda was the strongest.

    The End

  19. Sandra says:

    Thankyou for another interesting article. The SDZ is great in keeping us not only informed but providing information that peaks our curiosity!!

    As for Bai and Gao, I too hope they give us one more cub(s), but they have been so successful over the years that it will not be too disappointing if it doesn’t happen. We are all so thankful for the cubbies they have produced over the years.

  20. Mary from Brooklyn says:

    what an informative article! thanks. learned a lot about the reabsorption process. nature’s way of making sure the fittest get born?

  21. Susan, PA says:

    Will Su Lin and Zhen Zhen when they have cubies have them taken away? It would be a shame if there cubies never got to stay and learn all the teachings of grandma Bia.

  22. PandaLover says:

    Voting for the Vienna cubbie is open to the public. The choices are:

    Fu Hu 福虎 glücklicher Tiger, happy tiger

    Ao Kang 奥康 gesunder österreichischer Bub, healthy Austrian boy

    Wei Xing 维兴 Freude Wiens, joy of Vienna

    My choice is Wei Xing.

    You can vote here: www (dot) zoovienna (dot) at/

  23. Danielle, NY says:

    If you want to take part in the choosing of the name for the panda cub in Vienna, you have until Sunday November 21th, 2010, midnight (local time). www(dot)zoovienna(dot)at/

    You can choose from three names:

    Fu Hu 福虎 – glücklicher Tiger, happy tiger

    Ao Kang 奥康 – gesunder österreichischer Bub, healthy Austrian boy

    Wei Xing 维兴 – Freude Wiens, joy of Vienna

  24. Diane Lincoln, Ca. says:

    Thank you for the great article on reabsorption of a fetus in the uterus. That was explained very well.

    Trust we will have a new little panda in 2011. Lun Lun and her little panda will keep our attention this year.

    Looking forward to seeing the family back in their old digs! How is the decorating coming along?

    Moderator’s note: We hope to have a post soon about the remodeling.

  25. Laurie in Baltimore says:

    Thank you for the awesomely informative blog. Very interesting and relevant. Answers a lot of questions. Yes, hopefully, Bai will produce another cub next year and some generous organization will donte the use of a 3-D ultrasound machine as happened in Atlanta. 😀

  26. Teresa, TN says:

    I finally uploaded the pics I took of Su Lin and Zhen Zhen on my trip to San Diego Zoo last year. So if you are still missing the girls, check out the pics near the bottom of my page, they look so cute!

  27. Danielle, NY says:

    If you want an overdose of cute cubs, meet the Chengdu class of 2010!!


    In the pictures of the group of six, the youngest and smaller cubs are Yuan Lin & Yuan Zhou, born on August 15, 2010. They were still in an incubator in the nursery when the older cubs, Jiao Qing, Er Xi, Zhen Hao & Zhen Qiao, were already in a crib when Jeroen was in Chengdu. (one cub is on the keeper’s laps. The cubs were born on July 15 (Jiao Qing) and 26 (Er Xi) and twins on August 6 (Zhen Qiao and Zhen Hao). As usual the translation from Chinese into English is not all that good. On a lot of pictures there are 6 cubs, I believe they are the six from the pictures taken by Jeroen while he was in Chengdu. Then all of a sudden on the grass there are seven cubs!!! The seventh cub could be Ya Ya’s cub born on September 10, but I couldn’t find the gender or name of that cub. Perhaps someone on this blog knows… With the twins in Japan and in Spain, and now Lun Lun’s cub, there are 12 cubs born in 2010 and “belonging” to Chengdu.

  28. Ruth from Austria says:

    Thank you, Barbara, for taking the time to supply us panda lovers with such an informative and interesting report. I was very surprised to learn that pandas could even have triplets. However, I guess not in the wild where the panda mother would have problems even with twins. Has it happened anywhere so far that a panda female had triplets at all?

    No entry in the Vienna panda diary. But the zoo has offered 3 names for Fu Long’s little baby brother. Apparently voting has started already on the zoo’s website and will close on Sunday, 21st November. Here are is the choice for names:

    Fu Hu – happy tiger (Chinese year of the tiger)

    Ao Kang – healthy Austrian boy

    Wei Xing – Vienna’s pleasure

    At this stage I am not sure which name to choose also because I do not know how to pronounce the Chinese names. Could someone of you panda lovers please help? Thank you.

  29. shirley t says:

    I just watched the video of the birth of Lun Lun’s cub. As was the case with the video of Yun Zi, there was no sign of an umbillical cord. Both Lun Lun and Bai Yun picked up their cubs a second after birth and hadn’t been in a position to cut the cord at the moment of birth. Any comments?

  30. shirley t says:

    Also, is it unusual for a panda to give birth in winter?

  31. Danielle, NY says:

    #28 Ruth from Austria – To hear how the Chinese names sound like, go to Google, open “Language tools”, paste the Chinese name in the “Translate text” box and select Chinese and the language you want to translate it into. You can then listen to how it sounds in Chinese by clicking on “listen” under the box in which you pasted the Chinese name.

  32. Frances in NYC says:

    Such interesting news about pandas these days–in addition to the amazing 3D and 4D views of Lun Lun’s cubbie, the adorable groups of cubbies in Jeroen’s photos, the cute pictures accompanying the voting page for the Vienna cubbie’s name, new stories from Lucilla, new pix of our girls before they went to China, and now this, from “Panda News”:

    “Panda News : 2.6 Million Year Old Giant Panda Fossil Found

    Posted: 07 Nov 2010 01:09 PM PST

    In September, three teams of villagers of Pengpu Country in Qingjiang district of Chongqing found 10 pieces of strange stones shaped like bones the day after blasting the area.

    Later a total of over 100 pieces were found, experts have been examining the pieces and have come to the conclusion that the bones belong to giant pandas, oriental stegodons and other mammals.”

    I have read that pandas have been around since the dinosaurs, and this news would seem to support that. Such amazing creatures, now and then!

  33. Bobbie Wood says:

    Frances # 32: That is so neat! Thank you for mentioning the article!

    Teresa # 26: Thank you for your link to the photos!

    To All: DoxiMom has been posting videos of Lun Lun and her new cubby on her flikr site! They are so sweet! Here’s a link:

    To Rita: I am always in awe when viewing your photos! They are fantastic! to all: here’s a link:

  34. Dianna from Ohio says:

    #33 Bobbie: I didn’t know that DoxiMom was capturing those!! How cool! Thanks for letting us know. Has anyone noticed that when Lun Lun does her “panda snowball position” it’s always in the same spot of her bed and she always sticks our her right back leg…. 🙂 She also seems to have the “fluffy butt swivel” down to a fine art…

    The latest RitaPetita pictures are really good… Bai looks especially pretty and there is one of Yunior that is adorable… he is looking sideways back at Rita I think…

  35. Dianna from Ohio says:

    Weegee: How is the Royal Panda Family in Thailand? I’ve been watching a bit of Ah Ping and it seems that a couple nights they were flashing back to when Ah Ping was a baby on up… CK had several different hair styles and HK looked different too in some of his narration. I’ve also seen Ah Ping with Ah Hui sleeping. You can’t tell the difference between the 2 now… I always have to look for Ah Hui’s brown spot on her back.

    Are the bears spending any time outside now?

    Hope your 4-legged son is okay..

  36. pandafan-north says:

    #17 Danielle NY – You’re welcome! Oh, I wish I could watch the cams for an hour – maybe after I’m retired I will be able to. To get to these videos, I just go to youTube and search for ‘panda Mei Lan’ then sort by Upload Date to get at the latest ones.

    You’re right about Mei being reluctant to wander around at the beginning – poor girl was having separation anxiety, I think. But now, I think she’s gotten aclimated to her surroundings and is like any giant panda at Chengdu – she does enjoy her yards.

  37. Danielle, NY says:

    Jeroen has posted the pictures of Bao Bao taken at the Berlin Zoo. As I mentioned earlier Bao Bao was celebrating the 30th Anniversary of his arrival in Berlin on November 5, 2010.

    Bao Bao is 32 years old and looks as he is doing very well for such an advance age. In case you wonder, yes, his teeth are still in good shape too…

    Besides eating all his veggies, Bao Bao still likes his pretzel

    Also see www(dot)giantpandazoo(dot)com/panda/http:/

  38. Danielle, NY says:

    I came across this video of Tai Shan taken on November 5, 2010. Who said he is too old to climb up trees!! He seems to enjoy himself and has a lot of admirers in Bifengxia.

  39. Panda Team says:

    #29 and #30 shirley t

    The umbilical cord is there, but it breaks when the cub is expelled.

    It is unusual to have a panda birth in winter, though it has been documented before.

  40. Susan Ostanek says:

    Thanks for this very informative blog!

  41. P Wong says:

    #28, Ruth from Austria. Hi, I uploaded Chinese pronunciation of 3 panda cub name options.

  42. kat wilson says:

    Barbara, thank you so much for this great information, so informative!

    #33-Bobbie, thanks for these sites, checked out Ms. Lun and wee lun, soooo sweet, mommie beautiful.

    …and Rita outdid herself this time, those pictures of Little Cloud and mum are breathtaking. I can hear Little Cloud whisper to mum “I wish it could be this way always…”

    …I do too, most beautiful ones.


  43. Ruth from Austria says:

    #31 Danielle, NY, thank you for pointing out the language tool to me, most helpful. #41 P. Wong, thank you for uploading the Chinese pronounciation of the 3 panda cub name options. Here the names do not sound too difficult to pronounce. However, when using the language tool I came across so many options for one name and its pronounciation that I did not know which one to use. At this stage Wei Xing seems to be the favourite. I feel that the cub is not only the joy of Vienna so I tend to go for Ao Kang or Fu Hu which can be easily mixed up with Fu Long for non-Chinese people. On the other hand it is the Chinese year of the tiger and it looks as if the cub will grow into a big one.

    When using the language tool I tried out to draw some Chinese characters which was rather difficult and needs a lot of practising. The Chinese characters are sure an art!

  44. Dianne in Texas says:

    #38…Danielle, NY….thank you for posting the link for the video of Tai Shan. It’s good to know he hasn’t forgot how to entertain the crowd! 🙂 It reminded me of his younger days at NZ; climbing acrobatics, rolling down hills, etc. I really do miss those bright eyes, and that mischievous look. I also distinctly heard the roar of what sounded like a lion. Is there a zoo on the same property at BiFengXia? Can anyone answer that?

  45. Dianne in Texas says:

    Also, thank you, Barbara, for this fascinating report of tracking panda pregnancies. I had read, on the Memphis Zoo site, about the test to detect pregnancy before a fetus is visible. Hopefully, this technology can be advanced so that all the zoos can utilize the process with a reliable degree of accuracy. All of this is exciting and fascinating technology.

  46. TonyMo says:

    I cant decide if i’m a purist, or just a snob… while i’m happy for Atlanta and Viena, and i smile at Thailand, nothin makes me happier than our own panda family here. I still miss Pooper,,, he was my first panda to watch from birth to bye bye.. and still surf for news of his doings.

  47. Toni says:

    Around noonish give or take, Lun at the Zoo Atlanta leaves her baby cub for just a short time. I believe the cub is a GIRL!

    I have to say that the SD Zoo was my first and holds the special place in my heart. Yun Zi is still my favorite little guy. : ) I just have it all planned….Yuni Zi can hook up with what I believe is a gal in Atlanta.

  48. Toni says:

    Well..I was wrong. It’s a boy!