The Mature Panda

Bai Yun will be 15 years old on September 7. She will not really notice as her birthday passes; she will be busily engrossed in her daily routine of feeding and caring for herself and her yearling cub, Su Lin. But this time next year will she be caring for another newborn cub?

The oldest giant panda at Wolong to ever give birth was Jia Jia. That old girl was born in 1978, but gave birth to twins in 1996 at the age of 18. Several other female pandas in Wolong have given birth in their late teens, females like “Number One,” who gave birth to triplets in 1999 at the age of 16. As such, there is no reason to expect that Bai Yun won’t continue to be fertile for another year or two.

It seems common that the female panda senesces at about age 17 or 18. At this point they cease to give birth successfully, although they may continue to have an estrus in the spring and may even breed. Within a year or two, however, their estrus cycle will cease to be evident and the bears will no longer show interest in breeding.

The bears can still live long lives beyond their senescence. For those of you with an itch to travel, you can still visit Jia Jia at her residence in Hong Kong’s Ocean Park; she’s now 28 years of age! As far as males go, our own Shi Shi was estimated to have been born in the wild in the late 1970s, and so may be as old or older than Jia Jia. The National Zoo’s first male panda, Hsing Hsing, died at age 28. Bai Yun certainly has many happy years ahead of her.

How much longer will she be able to produce cubs? This is a bit of an unknown. Unlike most pandas in Chinese facilities, Bai Yun has never given birth in consecutive years. We will have to see if this management regime has an impact on her fertility as she ages. It is possible that a less demanding birthing schedule may result in a longer period of fertility. It’s also possible that the timing of senescence in the female panda may be hardwired and is not affected by how many pregnancies she sustains or cubs she gives birth to. Here is yet another opportunity for Bai Yun to inform us about another aspect of panda life… we’ll just have to wait a few years before she reveals the answer!

Suzanne Hall is the senior research laboratory technician for the Giant Panda Conservation Unit of the Applied Animal Ecology Division/CRES.

Watch Bai Yun and our other pandas on Panda Cam.