Growth and Development of Giant Panda Cubs

Growth and Development of Giant Panda Cubs: A Timeline
At birth Just 1/900th of their mother's weight, a newborn panda is born pink, covered in sparse, short white hairs. It weighs three to five ounces, and is about seven inches long, including a proportionately long tail. Its eyes are shut tightly. It cries loudly and often.
Days oldThe cub's limbs are weak—it will be several weeks before it can crawl. It continues to vocalize, to communicate its needs and strengthen the relationship with its mother. The cub spends its days sleeping and suckling often. At about a week old, black patches appear on the skin around the eyes, ears, shoulders, and legs. Black hair will grow in these areas in a couple of weeks. The mother frequently licks the cub to stimulate urination and defecation and to clean the cub.
One to two months oldAfter about a month, the cub resembles a miniature adult with a longer tail. It vocalizes less and less until it ceases crying and squealing by the time it is two months old. Its eyes open partway after 30 to 45 days and open fully a week or two later.
The mother may not leave to eat bamboo until her baby is three or four weeks old. By this time, the baby can better regulate its body temperature and does not require constant contact with its mother to stay warm. Mother has been staying busy providing the cub with high-fat milk. It may grow to ten times its birth weight in five to six weeks. At two months, it suckles three to four times a day.
Three to four months old The cub can stand and walk a few steps after about 75 to 80 days. At about this time, teeth begin to erupt. The order in which they appear varies from one panda to another. Its eyesight improves, and its hearing becomes more acute. It suckles two to three times a day. At four months old, the cub is active, running several steps at a time and climbing up on its mother's back to play.
Five months to one year oldAt five months, the cub trots behind its mother, mimics her while she eats bamboo, and climbs trees. It may sit in a tree by itself for hours. At six months, it has 26 to 28 teeth and begins to eat solids. It will have deciduous teeth at one year of age, and its permanent teeth will start to erupt at this age. It suckles only once or twice a day. It may continue to suckle at eight or nine months old. By age one, it may weigh 50 to 60 pounds.
One and a half years oldIn the wild, the cub leaves its mother at one and a half to two years of age.
See how Tai Shan has grown.

PandaTai Shan

Tai Shan now weighs 148 pounds. We have been rotating him into enclosures adjacent to Mei Xiang in preparation for some floor repair in one of the indoor exhibits. Mei shows no interest in him. He has been nonchalant but very interested in the scent marks of both adults. When shifted into Yard Two, he spends a lot of time sniffing and exploring. Tian and Tai did not pay any attention to each other through the windows even though they had the opportunity to interact. The repair work will take three days and is scheduled to begin this week.
Mei Xiang has been rather lethargic these days, sleeping in the water-chilled grotto or in her air-conditioned indoor enclosures. When it is so hot and humid, we all wish we could curl up and take a nap with her. Over the weekend, she declined to go outside, but today she decided she wanted to go outside again. She has been eating much less, only about 11 pounds of bamboo daily, compared with as much as 44 pounds a day in the winter. She has also been leaving some of her produce and biscuits. She has been shredding bamboo off and on in Den Three, the den she used in 2005. In the meantime, we are making all the preparations we can in case she is pregnant, hoping that there will be a cub in the future.
Pandas experience delayed implantation.

Her hormone profile tells us that she may—MAY!—have implanted around May 28. Although panda gestation may range from three to six months (from insemination to birth), actual gestation is quite short, just 40 to 50 days (from implantation to birth). One day, someone very brilliant and who will be much celebrated, will figure out how to determine pregnancy in the giant panda, and we will all miss being asked "Is she?" In the meantime, we will be sure to share our news with you.

May 17: Tai's Training Is Going Well
Tai Shan weighs in these days at 137 pounds! Even though he is almost half the weight of his big daddy, Tian Tian, he still has his long, fluffy, cub coat, and the youthful look that goes with it.
Tai has made a lot of progress in his training. He now presents all four paws as well as his tail on request. The latter behavior requires him to scooch forward to present the underside for inspection. Very cute! Tai is making progress with the blood sleeve, which allows us to quickly draw blood, and will now hold the bar securely in his paw. We are working on correct positioning and holding still.
Tai continues to favor the area on the far side of the new exhibit by the glass. He brings immeasurable joy to everyone who passes there. This is a great place to cheer up if your spirits are low. Tai Shan has also been having some wild play sessions running all over the yard and hanging upside down from the trees.
All our pandas are still shredding bamboo and also shedding right now. Tai Shan looks like someone slipped him out to a groomer, who clipped the long hairs, leaving the brown undercoat exposed, in a perfectly symmetrical line, on both his hind legs.
Mei Xiang and Tian Tian have been separated since April 24. Tian, who was still in the midst of his breeding rut, was particularly persistent in annoying Mei to the point where it escalated into a fight. Except for a minor scratch on Tian’s nose, no injuries occurred. Mei Xiang has continued to make it clear that she is not interested in socializing with him. Recently, she has also started moaning when she hears Tai in adjacent enclosures. This vocalization indicates she may no longer be interested in contact with Tai Shan, either. As the pandas are moved between enclosures we will have the opportunity to monitor their behaviors through mesh barriers, and they will be able to investigate scent marks when they are rotated between enclosures.
Mei Xiang has also started carrying bamboo and shredding it at night, in den three. Due to delayed implantation of the embryo and the frequency of pseudo- (or false) pregnancy in giant pandas, the duration of gestation ranges between three and six months and cannot be determined definitively until a birth occurs or we learn from hormone analysis that the pseudopregnancy has ended. Our weekly ultrasound sessions may give us a couple weeks' notice. In the meantime, we are planning for the real event. Even though we see Tai Shan every day, it is still hard to believe 22 months have passed since the monumental event of his birth. And we may have another cub on the way!

April 24: Tai Will Stay at the Zoo for Two More Years!
We are very happy to announce that Tai Shan will remain at the Zoo for two years past his second birthday, which is July 9. John Berry, director of the National Zoo, reached an agreement with the China Wildlife Conservation Association to extend Tai's stay during his recent visit to China. Under the current loan agreement the Zoo has with China, any giant panda cub born at the Zoo belongs to China and would be sent to a reserve there sometime after the cub's second birthday.
We are delighted that we can continue watching him grow and develop, and are glad that many more people will have the chance to visit him here and keep watching him on our cams. Adopt a giant panda.
April 18: Mei and Tian Are Together by Day
Mei Xiang and Tian Tian are spending most of each day together. They are doing well, playing and eating together. Tian tends to want to wrestle and play more than Mei does—and she lets him know. When she has had enough, she swats or chases him, and he runs away. But he comes right back to try his luck again. When we determine that Mei needs a break, we separate them. And they spend each night apart.
Tai Shan is also doing well. His weight has climbed up to 122 pounds.

thank

http://nationalzoo.si.edu/Animals/GiantPandas/CubUpdates/