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Posted at 10:00 am March 7, 2007 by Suzanne HallWho’s that in the left exhibit? Who’s that in the “Keebler den” area? How well do you know our pandas by their appearance? Your sharp eye and panda recognitions skills will be tested in the coming weeks, because we have instituted a new panda rotation at the San Diego Zoo. Let me explain…
As you may be aware, spring is the typical time for mating activity between adult pandas. In China and in managed-care facilities across the Americas and Japan, adult pandas of both genders will undergo a series of physical, hormonal, and behavioral changes in preparation for breeding. Male pandas will experience an enlargement of their testes associated with improved seasonal sperm production. Females undergo several changes to their vulvar region, including swelling and color changes. Behaviorally, males are more prone to restless wandering and scent marking, and females even more so. Females will descend into estrus by wandering for hours, forgoing food and traversing through the water along their restless travels. During this time, they gradually increase their rate of scent marking to a phenomenally high level. In this way they lay down a wide swath of scent which males will begin to pick up during their wanderings. This process takes approximately one to three weeks, depending on the female.
A few days before their optimal mating date, females reduce their scent marking and significantly increase their bleating and chirping. Presumably by this point the males in the area have cued in on her scent and have become aware of how close she might be to her estrus peak. They are close enough to hear her, and she draws them in with her calls. Finally they meet face to face, and if the two are amenable, they mate.
All of this is background for what we have started this week in San Diego: a new panda rotation. Each breeding year in the time before Bai Yun’s estrus, we allow the male and female to swap pens. We are allowing each adult bear to lay down their scent in an area that will soon be visited by another. In this way, Gao Gao has a chance to “read” what messages our female may have to send, and Bai Yun is afforded the opportunity to communicate her estrus status with the male. This is yet again an attempt to mirror the wild situation as much as possible. Since Bai Yun is not yet showing strong signs of estrus, the swap is currently occurring only a few times per week. As her estrus progresses, we will swap more frequently and ultimately, daily.
In addition to the rotation, we will begin opening the “howdy door” between them a few days per week. This door, a physical barrier between the bears that allows for visual and olfactory exchange, allows the pandas the chance to reacquaint themselves if they choose, or ignore each other unmolested if they prefer. In the wild, females who are not ready to mate will often run away from a male. In many captive facilities, females cannot run away and will therefore often fight with the male, and this can result in injury to either party. The howdy door is in the exhibit space, so visitors to the San Diego Zoo can watch the interesting encounters between the bears.
Those eagle-eyed among you may notice when the frequency of the rotation increases or when the howdy door is open more often. Those will be clues to you that the game is on, and Bai Yun’s estrus is off and rolling. In the past, she has peaked anywhere from mid-March to early April, so get your scorecards ready. And put me down for the first week of next month.
Suzanne Hall is the senior research laboratory technician for the Giant Panda Conservation Unit of Applied Animal Ecology/CRES.
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March 7th, 2007 at 10:06 am
animals,
their SOO Great!
March 7th, 2007 at 1:27 pm
thank you so much for all this info….very interesting how the zoos try to simulate the wild, and make it all so natural for the bears to act/react…..very fascinating how all the decisions are made.
great job!
March 7th, 2007 at 2:24 pm
Ooooh. This is so exciting =-) This is my first panda estrus as I started watching pandacam when Tai was 6 months old and I didn’t know that ZooAtlanta had pandas till after Mei Lan was 2 days old. I’m crossing my fingers for twins! Because the pandas don’t need to compete for food what would happen if the adults were put together when Bai wasn’t in estrus? Mei and Tian seem to enjoy playing with each other even though pandas are solitary and they aren’t ready to breed just yet.
March 7th, 2007 at 2:25 pm
Hi Suzanne - how time has flown when viewing the Pandacam daily and realise that ‘all things Panda’ have very successfully turned a full circle yet again - it must be very ‘enriching’ to both the Pandas and the staff who care for them.
I am a long distance ‘Pandafanatic’ (5,000 miles+) - recently I have seen Bai ‘walking the walk’ in anticipation of her liason with the lovely Gao Gao, even he did a few early morning circuits to help get himself in peak condition in readiness for the occasion.
I note that Bai already thinks that ‘Spring has Sprung’ and shows early signs of estrus but I would not like to make a guess at the date - possibly the last week in March or early April depending on what signs she gives us meanwhile.
I am always pleased to read of people’s enthusiasm who hope that Bai will produce twins - although it sounds great, we have been down that road before. As an ‘onlooker’ I consider it is preferable that she produces one fit and healthy cub which she can be happy with and care for competently herself, she will be an ‘older mum’ than her daughter Hua Mei.
I still miss Hua Mei, she is an immense credit to how she was reared and cared for at SDZ and has looked after twins competently with assistance from her keepers, Hua Mei was your first baby and is a ‘one off’.
Regards ‘long distance’ panda recognition, I am fairly confident I know ‘who is who’ when they are on the cam - I remember lovely Shi Shi and the day that Gao Gao arrived - he was still munching happily while he was in transit to his new home.
Thank you for keeping us up to date with all things Panda - yet again I am waiting for Bai to give the signs that she is ready and waiting!
Kind regards - meanwhile I will be watching and waiting!
March 7th, 2007 at 2:31 pm
Thanks, Suzanne, for another very enlightening article. I noticed that they appeared to be in opposite exhibits, and couldn’t tell if there was a howdy door open or not. Where is the door in the exhibit relative to the “cave” or the “tree trunk”. For Bai Yun this must bring back fresh memories since she was just in this area as recently as two weeks ago. For Gao, he hasn’t been in that exhibit since before Su Lin was born. Do you rotate Bai Yun out of “her” exhibit at all other than leading up to the actual mating phase? i.e. at any time after the mating and before the birth of subsequent cub(s) do you allow any of the other 3 pandas an opportunity to be in that exhibit for a few hours or days? I know the closer it gets to the birth of the cub(s) you close down the area, and let her be as stress free as possible. Would it stress her out before that to rotate out so that Su Lin or Mei Sheng could be in her exhibit for a visit to the space on their own? You mentioned that they might be allowed in an exhibit together after the mating takes place, and I thought it would be Exhibit 2. But is it possible it will be exhibit 1?
If a female goes on with their life while the fetus is developing, and then finally finds the “perfect” den for birthing, it would seem that during the first couple of months after breeding that she might enjoy the opportunity and enrichment of going to one of the other exhibit spaces for at least a few hours a day. It would give her a new “perspective” on her “forest.”
March 7th, 2007 at 2:46 pm
I don’t understand how or why there are frequently no pandas in the pandacam on your site. i would think with four pandas, one at least would always be “on camera.”
March 7th, 2007 at 6:25 pm
Wow, and we thought we humans had it rough with “mating”?!! Could you imagine if we had to go through what the pandas go through? Maybe that’s why it is only once a year for them!
March 8th, 2007 at 12:05 am
All the pandas look a little different. Gao Gao is the easiest to recognise as he is missing part of his ear and that sweet little face is so cute, yet they all have different features the more you study them the easier it is. I watched a documentary on a panda keeper in Wolong and he said he can recognise them all without seeing the names on their enclosures, just by the length of their whiskers, their ear positions,the markings on their backs and around their eyes. Bai Yun seems to have ears that are a little higher up on her head than the other bears, Mei Sheng seems a mixture of both parents and Su lin has a sweet inquisitive look to her face.Tai Shan always seems to have fur that is longer and a little raggy, as if he has been up to all sorts of trouble like a little naughty boy and Mei Xiang seems to have a very large, round face. I wonder if they observe humans in the same way! lol
March 8th, 2007 at 4:25 am
Thank you very much, Suzanne, for this detailed information on the mating game of pandas. Being rather a novice to the fascinating world of pandas as well as to the panda webcam I very much appreciate your updating us on the ongoings of your pandas. I wonder if I could ask you or other panda viewers (whose knowledge is more advanced than currently mine) a question, i. e. why are newborn pandas so tiny in relation to their mothers? Is it a matter of nutrition, i. e. a diet of more or less just vegetarian food? Or is there any other reason. Your answer is very much appreciated, thank you.
March 8th, 2007 at 10:40 am
I agree with Jo, #8, that you can tell the pandas apart with a little scrutiny. Besides Gao Gao’s left ear, he has a very round, large forehead, and yes, his ears are not as upright as Bai Yun’s. Mei Sheng’s ears are upright like his mama’s, and his shoulder stripe is very narrow. And we all know Bai Yun always has a smile. Regarding the NZP bears, Mei’s shoulder stripe is much wider than Tian’s.
Laine, #3, the theory of why SDZ doesn’t put their mating pair together except during mating season is that if they are together all the time, they play and are more like brother and sister. You can see that at NZP with Mei and Tian, who have not mated naturally. So, SDZ goes with this theory–and have natural matings–so at least in their case they are right on!
Isn’t it great to watch all the pandas! They each have a different personality.
March 8th, 2007 at 11:38 am
Ruth #9,
In all bear species, the newborns are very small, less than 10% of the weight of their mothers. Pandas share this trait with other members of the bear lineage, although they take it a bit farther. This is probably a “bet hedging” strategy, in that females don’t waste much energy on gestating their cubs only to see them fail to thrive once born. The energy wasted in gestation is important to a female that relies on a nutritionally poor food source (bamboo) to get by. If it’s a good year, she can afford to put more effort into rearing her offspring; in a bad year, if the cub dies, she hasn’t lost much energy in the process.
March 8th, 2007 at 12:59 pm
With the Howdy gate, Gao and Bai get to “interact” but not in close physical proximity. As Suzanne mentioned the chance of aggression between the male and a female that is “not ready” is too great to risk injury to either of the pair. Mei and Tian have always had a more playful relationship than most breeding pairs. Since Tian is not really in the picture for the breeding this year, I think the NZP is hoping that the presence of Tian will help Mei’s hormones get her ready to receive Gao’s contribution to the breeding process.
Besides Tian can get something from the deal and learn how to behave around a female in estrus, in case his sperm count goes up in the future. They are not sure what caused his sperm count to drop in the past year, and hope that it will return to “normal” levels. Tian has waited not so patiently for 2 years to be able to be around Mei at breeding time. I remember last year they said he was very restless during the normal breeding season.
Who knows, they might just fool all of us and have a natural breeding, but with the low sperm count, they will likely still need Gao’s contribution to produce a cub(s).
You go Gao, you are the ‘man!’
I can’t imagine the strain it must put on a mother panda to gestate a cub, then nurse it from the size of a stick of butter to a 100 pound animal, all from eating a nutrient-poor green leafy substance like bamboo. They are amazing creatures. I am glad they get the supplimental nutrients from their leaf-eater biscuits, etc. No wonder Bai Yun is eating like bamboo is about to become extinct, since she will be fasting for 4-6 weeks around cubbing time, and nursing for 18 months after that.
March 9th, 2007 at 5:59 am
Suzanne, thank you very much for your reply which is much appreciated. I always find it fascinating how nature seems to balance itself owing to the supply of food. I agree with Margaret’s comment that the whole process must put a lot of strain on a mother panda considering her being a herbivore. It always moves me watching a panda mother nursing and cuddling her baby. So, Bai Yun, you go for it and eat as much bamboo as possible in order to prepare yourself for (hopefully) having and rearing a cub!
March 9th, 2007 at 7:29 am
where o where have my panda bears gone , where o where can they be.I haven’t been able to find my babies. every time i checked in i don’t see them. Help I am going through panda withdrawl
March 9th, 2007 at 10:38 am
I have been reading here about the plans to inseminate Mei Xiang with Gao Gao’s sperm because of Tian’s low sperm count. Where did you learn about this? I read the posts of both zoos daily. I am a member of both zoos and receive their e-newsletters. I also get Google alerts on panda bears. But I haven’t seen this information except here in this blog. I thank my pandaholic friends who have shared this information, but where did you get it?
March 9th, 2007 at 1:04 pm
Thank you Pandalover #15. I would like to know the answer to this question also. I have read all of the information on this site as well as NZ Site and I can’t find anything that refers to using Gao Gao’s sperm to inseminate Mei Xiang either.
March 9th, 2007 at 1:47 pm
Pandalover - check the NZP messages from October when they discussed TianTian’s annual physical.
Since both zoos are involved, interaction and comments are available from both zoos in person, not necessarily in writing in blogs.
The person who first mentioned this last week said that one of the volunteers at the NZP Panda exhibit told them on a recent visit. Since both zoos are on constant research and hormone watch for that “magic panda moment,” of Mei Xiang and Bai Yun respectively, there is information available on-site at both facilities from the keepers and visitor greeters.
I have not read any “official” comment about this from SDZ, probably because it is more of a NZP situation/issue. It is up to NZP to disclose what they want to about the breeding circumstances with their pandas, just like SDZ discusses things that pertain specifically to the breeding of their pandas.
March 9th, 2007 at 2:29 pm
Pandalover #15,
We did collect sperm from Gao Gao this year to give to the NZP for use in the event of an AI. As far as I am aware, this has nothing to do with Tian’s sperm count, but rather is an attempt to increase genetic diversity in the cubs that may result. Both Tian and Bai Yun come from Pan Pan’s lineage, a highly overrepresented line in the captive population. Gao Gao is certain to have fathered only two offspring, and since he is a wildcaught male from a panda population distant from Wolong, his genes are very rare and valuable in the captive population. Using Gao’s genes in an AI is strictly an attempt to allow Gao to have more offspring, so that his genes can be more represented in the captive population as a whole. Since the NZP and SDZ animals are all from Wolong, it was easy to get permission to exchange the male sperm fo this purpose.
March 9th, 2007 at 3:54 pm
Thank you Margaret and Suzanne for all of the information. What exciting possibilities in Panda Land!
March 9th, 2007 at 4:36 pm
Thank you, Suzanne. I can see why NZP would want to use Gao Gao’s sperm. The statement about Tian having a low sperm count may be an assumption. Unfortunately, I live in Missouri and must rely on just what I read on the sites. I would love to be able to go regularly to see the pandas and ask questions of the narrators. Thank you again from all of us who are in the same position as I am.
March 9th, 2007 at 4:54 pm
Thank you, thank you, thank you, SDZ staff… for sharing all this information with us panda fans. The time you take to write these blogs and respond to comments is very much appreciated.
March 11th, 2007 at 5:05 pm
Suzanne, thanks for the clarification. Prior to reading the comment someone made a couple of weeks ago about what the person at NZP told them about using GaoGao’s sperm, the only published comment I saw was about Tian Tian’s low sperm count and how disappointed they were.
It is great to know that the AI is being done to help diversify the gene pool. I didn’t realize that in addition to the fact that he was a wild caught male (valuable) he came from “a panda population distant from Wolong” which would make his sperm extremely valuable. And he is the only male in the US that has bred naturally - twice!!! By using the AI process in US it helps Wolong get the results they are trying to achieve while the animals are here, and they don’t have to wait until they return to China. Hopefully it also allows for future mating possiblities for US born pandas to be bred here.
These blogs are incredibly educational, and a priceless opportunity to learn more about the cooperation going on world-wide for panda conservation. Thanks to everyone for patiently explaining, and answering our questions.
April 6th, 2007 at 12:49 pm
i am happy your pandas are doing well. i am not happy mexico city zoo still does not have a new breeding male from china xin-xin and her aunts should be breeding and having cubs as well. we save all the pandas not just the ones in china and pandas on loans. i hope that china will do the right thing and send a new breeding male to mexico city zoo