Smithsonian National Zoological Park l Friends of the National Zoo



August 2008 Updates

August 19

Mei Xiang has not been seen cradling objects and grooming herself since last Thursday. She has been going outdoors for a few hours each morning since last Friday. A few hours is her plan, along with quick-stepping keepers. Mei is still very attached to her den, off of exhibit three, huffing, honking, snorting, and head-tossing if we take too long to clean. The first time she went outdoors, she sniffed the yard over thoroughly until she had had enough and wanted to come inside. When she is outdoors or hungry she is her old self again. Mei is eating really well and has the best bamboo consumption of the three pandas.

Over the past few days, we have been able to get caught up with our routine blood-pressure measurements and blood draws for all pandas. They are active early and then the summer lethargy sets in. Tian Tian has been spending a lot of time on his back in his air-conditioned grotto, but by the peak heat of the day he is ready to retreat indoors. Tai Shan has been sleeping in late most mornings. When Tai goes outdoors, he is back in his habit of sleeping on one of the two drainage grates. Although he was using the water-chilled grotto in yards three and four earlier in the summer, we have not seen him there recently.

We are also catching up on making repairs and cleaning. Our entire camera system is being renovated or replaced, thanks to support from Discovery. Electricians have adjusted the "hot vines" (electrified faux vines) for the growth and well being of the trees. Plumbers have repaired one of our most important appliances. It has been a busy week already.

August 13

Zoo staff confirmed today that Mei Xiang will not give birth to a cub this year. They believe that she experienced either a pseudopregnancy or the loss of a developing fetus. In a pseudopregnancy, an animal's hormonal changes and behaviors are identical to a pregnancy, but no conception occurred. Fetal loss during early pregnancy is a common occurrence in mammals, but the reasons for this phenomenon are poorly understood.

As you read in these updates, Zoo scientists, veterinarians, and keepers were closely watching Mei Xiang, assessing her hormone levels and behavior and conducting weekly ultrasounds in an attempt to determine if she was pregnant. Veterinarians noted small changes in Mei Xiang's uterus but they were unable to confirm the presence of a fetus. Giant panda fetuses are very small—a newborn cub is only five inches long. At other zoos, fetuses have been visible on ultrasound only in the last weeks before birth.

In mid-July Mei Xiang's urinary progesterone levels (a hormone associated with pregnancy) began to decline. In pregnant pandas, declining hormones and increased maternal behaviors signal an impending birth. This year, Mei Xiang's hormones declined as expected, but the decline lasted longer than normal and she continued to show maternal behavior even after her hormones reached baseline. The Zoo's scientists and veterinarians speculate that Mei Xiang may have experienced the loss of an early-stage fetus that failed to develop normally, and it was absorbed into the lining of the uterus. In the coming days, we expect Mei to return to "normal," both hormonally and behaviorally, experiencing an increase in appetite and activity level.

Last night, Mei showed very little maternal behavior. The volunteers recorded only 46 minutes of Kong toy cradling in two sessions, one lasting 12 minutes and one lasting 34 minutes. Otherwise, there were no other behaviors observed last night. This morning Mei was very alert and curious about the activities of the keeper staff. After an ultrasound and some bamboo, Mei slept in her den the rest of the day. We observed only a few minutes of paw licking today.

We will return to our normal schedule tomorrow. Mei will go outside again, and we will return to analyzing urine samples on a weekly basis instead of daily.

We offer our sincerest gratitude to everyone for supporting our program this year. We could not have operated so smoothly without everyone's effort. Special thanks to all the dedicated FONZ volunteers on our 24-hour watch who recorded Mei Xiang's behaviors.

Our staff are recognized leaders in the study of giant panda reproduction. Each year, hormone analysis, behavior observations, and ultrasound technology help us learn more about pregnancy and pseudopregnancy, and may show us how common fetal loss is for giant pandas.

Thanks to everyone who has been following the pregnancy watch along with us. While we all would have been thrilled to welcome a baby giant panda this year, we have learned a great deal about this fascinating species and hope you have too. We are happy to have three healthy pandas, and enjoy providing you with a window into the world of our pandas and show how we care for them and work to conserve this endangered species.

We encourage panda fans to support our conservation efforts by making a donation to the Giant Panda Conservation Fund.

August 12

Mei Xiang is still spending her time in den three, sleeping and cuddling her toys. After the 14 minutes of ano-genital licking yesterday evening, there were only two more observations last night, lasting for four minutes and 30 seconds, respectively.

Mei was more alert this morning. She was up at the window in the den door watching the keepers get set up for an ultrasound. She came out of the den and went into exhibit two to eat bamboo earlier than usual. Lately, this has only happened in the afternoon.

This is the time of year when none of the pandas eat bamboo very well. We rotate different kinds of bamboo, hoping to pique their interest. During the hot-weather months, they seem to like yellow groove the least, with a slightly greater preference for bisetti. They will usually eat arrow bamboo the best. The lazy days of summer are here!

August 11

Mei Xiang’s behavior is similar to what was reported yesterday. She is spending most of her time sleeping in the den and cradling her toys. Since yesterday afternoon, she has spent nearly four hours cradling objects. Mei now has a second smaller ball to cradle. She still tries to cradle the Kong toy and a ball at the same time. Other behaviors we observed were: paw-licking for ten minutes, nest-building for two minutes, and ano-genital licking for 12 minutes. In the early evening, she had three episodes of ano-genital licking totaling 14 minutes. Mei Xiang is now asleep.

Earlier in the day, Mei had a good appetite and participated in an ultrasound procedure. She also was up at the window in the den door, asking for food. She came out of the den to eat bamboo at 2 p.m.

August 10

Mei Xiang has spent most of her time in den three since yesterday afternon. Other than sleeping and resting, she has cradled the Kong toy or Boomer ball for nearly five hours. We all wish she was cradling a real cub. We have observed only a small amount of body grooming. Ano-genital licking was observed for a total of 15 minutes There were four bouts; the longest session was seven minutes and the rest were three minutes or less.

Mei Xiang came out of her den when called for an ultrasound this morning. As soon as the procedure was over, she retrieved a piece of bamboo and returned to the den to eat it.

August 9

Mei Xiang was alert this morning and came out of the den immediately for her ultrasound. She was so ready that she came into the training cage and laid down on her back in position, before being asked. Once the procedure was finished, she wanted to stay outdoors and was left to wander in the runway. At one point, she went back into the training cage on her own and assumed the ultrasound position, just waiting for the keeper to notice and provide more attention and treats! Mei Xiang is very food-motivated again, eating all of her apple instead of nibbling around it. She spent most of the rest of the day in den three.

Mei is still cradling, and licking her body. When she drags bamboo to the den, she usually eats it. We observed only one episode of nest building. There has been ano-genital licking observed several times in the past 24 hours but no signs of labor have followed. After a series of ano-genital licking between 10:20 and 11:18 last night, she left the den at midnight and dragged bamboo into the den to commence stripping and eating it. Between 12:24 and 6:14 a.m., volunteers observed four bouts of licking; three of them lasted one or two minutes, and one was six minutes long.

August 8

According to Chinese culture, today is a very lucky day.We are all excited about the start of the Olympic games. It would be wonderful if some luck was directed at a certain panda den.

Mei Xiang continues to cradle her Kong toy and do some intermittent ano-genital licking. Overnight there was a total 43 minutes of cradling. There were only brief episodes of paw licking and nest building. Mei did some ano-genital licking for a total of 18 minutes overnight and this morning. The longest bout was nine minutes.

We collected one urine sample this morning, but it didn't make it to the facility where we conduct these analyses, so there will be no results for today. Mei has not provided any more urine samples.

August 7

Mei Xiang has been spending more time in her den. She has created the biggest pile of bamboo we have ever seen in there. It is a wonder that she can get through the door to her place beside the bed.

Mei has also been showing more pregnancy behaviors. In particular, she has been cradling the Kong toy for a total of four hours and 45 minutes in four time frames: at 4:14, 7, and 10:04 a.m., and 1:30 p.m. We also saw ano-genital licking for 11 minutes at 4:14 a.m. and another five minutes at 1:39 p.m. Ano-genital licking as well as the increase in cradling behavior is a signal that we are reaching the end of a pregnancy or pseudopregnancy.

Mei left the den at 2:30 this afternoon and dragged another piece of bamboo into the den and proceeded to eat for at least 45 minutes. She continues to have an excellent appetite. Two urine samples were collected this morning from 4:09 and 7:40 a.m. Mei has not urinated today.

August 6

Mei Xiang spent time today cradling one of her boomer balls. This hard plastic ball, which is 12 inches in diameter, was made for zoo animal enrichment. This giant-sized surrogate cub was quite the challenge to cuddle. At times, she managed to cradle the Kong toy and the boomer ball at the same time! Could this be some form of juggling practice for twins!? There have been a few reports of female pandas rearing twins, but this is a rare accomplishment, as each panda cub needs intense maternal care. All this activity took up 41 minutes of her time, starting at 10:53 this morning and continuing on and off into the afternoon. She did not produce any urine today. The wait for Mei’s progestins to reach baseline continues.

August 5

Mei Xiang slept in the den last night. Our volunteers observed 11 minutes of moving bamboo, nest building, and then eating the bamboo, beginning at 7:31 p.m. About half an hour later, Mei spent five minutes cradling the Kong toy, and toward the end of the hour, she had a three-minute episode of paw licking. Near midnight, she cradled her Kong toy for 31 minutes, and for 18 of those minutes she was also licking the Kong, her abdomen, and possibly her nipples. This was the most extensive behavior observed all night.

This morning, Mei came out to the training cage when called and participated calmly in the ultrasound procedure. Mei declined to hold her arm still for a blood sample, withdrawing it from the sleeve, and patiently waiting for her treats anyway, while remaining seated in the training cage. It is typical for her to be touchy about some of her training when she is “pregnant” however she was so relaxed, we decided to give it a try. Mei, in her quiet way, let us know it was not part of her plan.

Mei produced a nice fresh urine sample at 7:55 a.m. before calling it a day—on the rocks in exhibit three. She may have urinated again while defecating at 10:17 a.m. From the top of the rocks, it was difficult to confirm, as it all dropped into a pile of bamboo. She remained asleep in the enclosure and did not shift for the rest of the day. As I write this at 3:55 p.m., she is still asleep.

August 4

Mei Xiang continues to show some pregnancy behaviors and completely baffle us with her alert and active demeanor when awake. Log cuddling, chewing, and shredding seemed to be her preferred activity last night and this morning. She was busy with this activity for 42 minutes, beginning at 1:26 a.m., for 18 minutes at about 6 a.m., and for another seven minutes a couple of hours later. The next most frequent behavior was paw licking, for a total of 20 minutes over five episodes. Mei cradled her Kong toy only briefly.

Mei was very active and interactive with the keepers when she was awake. She slept from 10 a.m. to 2 p.m. When she woke up, she ate bamboo for an hour. She also ate a fruitcicle today. No urine had been produced as of 3 p.m.

August 3

As I write, Mei Xiang has returned to her den for the first time since getting up this morning. She is buried in her nest, partially covered with hay and bamboo, and dining in repose.

This morning Mei was very active, getting up when called, and standing up to take a bag of leaf-eater biscuits through the window in the den door. After an ultrasound and with a full belly, she spent the rest of the day asleep in exhibit three, on the rocks.

Mei continues to show maternal behaviors. Overnight, she did eight minutes of paw licking, three minutes of nest building, two minutes of nipple licking, and five minutes of cradling (just her Kong toy this time). Unlike previous nights, she was active at 7:56 and 11:30 p.m., then slept until 5 a.m. She produced two urine samples during the day today, at 1 and 3 p.m.

August 2

Mei Xiang was up at the window in the door this morning when she heard the keeper had arrived. She was ready for an ultrasound but was quite jumpy once she was lying in the training cage. Her uterus is still enlarged but nothing significant has appeared. Mei kept sniffing around the training cage, making us wonder if a little intruder had come through recently.

This must be the year of the chipmunk at the Zoo. There are chipmunks zipping around everywhere. There is such delight in the voices of young and old, as they exclaim, "Look, a chipmunk!" It is not unusual to see visitors, both local and from afar, peering into the bushes trying to get another look at the little brown essence of busy that just darted across the path in front of them. One of our resident chipmunks has discovered that the panda runway between the yards is also its personal pathway. As one keeper described it: "It zips down the runway over thresholds, through the openings in the mesh doors, and around corners like it is running its own agility course."

Mei Xiang is far from busy. She is spending most of her time sleeping. There were some moments of pregnancy behavior, mostly nest building and paw licking. She also cradled all forms of a surrogate cub—the drain grate, her Kong toy, and even the log. She indicated that she wanted to go outside at 2 p.m. and was given access to the patio, where she sat and ate all of her produce. She produced two urine samples today, at 7:30 a.m. and 1:45 p.m.

August 1

It is the beginning of August and all of us thought we would have an answer to the big question by now! Here we are, still hoping for a cub.

Mei Xiang slept from around 2:30 p.m. yesterday until just after midnight. After she woke up, she occupied herself paw licking for four minutes, nipple licking for ten minutes, and dragging bamboo into the den before falling back to sleep.

She was quite herself this morning. She came out for the ultrasound between 7:45 and 8:30 a.m. and was only slightly jumpy. She was bright-eyed and chewed her food with more energy than we have recently observed. Mei especially enjoyed slurping down two rather juicy pieces of sugar cane as a reward for her cooperation. She shreds and leaves the outer culm of the cane, just like when eating bamboo, and then she gets down to business on the inner part. Mei also engaged in quite a bit of paw and body licking to clean up all of the sweet remnants. Mei slept all day and when she awakened around 3 p.m., she moved to the den and began to eat her nest. Never mind that there was ten kilograms of fresh bamboo, nicely refreshed by the mister in the storage shed, waiting in her enclosures.

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