Su Lin and Zhen Zhen left the San Diego Zoo Friday evening, September 24, under the watchful eye of the California Highway Patrol! After being escorted by Zoo staff and the CHP, the duo left by plane to Shanghai in the early hours this morning, accompanied by Gaylene Thomas, the animal care supervisor who oversees giant pandas, and Tracy Clippinger, a senior veterinarian whom you’ll remember from many panda exams. The pandas were acclimated to their new traveling crates, as well as being next to each other, over the last several months. The crates were designed especially for these two pandas, giving them privacy and ventilation at the same time. During their voyage, the crates were placed adjacent to one another to provide them with familiar smells and sounds, while Gaylene made sure they had their favorite treats and even honey water to keep them comfortable. Su Lin and Zhen Zhen will be welcomed in Shanghai by a team of experienced panda keepers and escorted to their new home at Wolong Nature Reserve Giant Panda Bi Feng Xia Base in Sichuan, China.
I think it’s safe to say that we were all lucky to have gotten to know both of these charming bears, and both of them contributed valuable information to our understanding of giant panda biology. Su Lin is the first giant panda to have contributed comprehensive data for our panda hearing study. Her patient and playful focus over the last year and a half has taught us a lot about the sensitive hearing that pandas have at certain frequencies. This important starting point will help guide our research into the impacts of human disturbance on giant pandas in the wild.Su Lin’s behavioral development, from birth to weaning, was also well documented as part of our detailed behavioral studies of this critical period in a panda’s life. And of course, over the last year, Su Lin has displayed clear signs of the onset of reproductive maturity, both behaviorally and physiologically, and we have no doubt that she will go on to be an important contributor to the panda population at Bi Feng Xia, just like her big sister, Hua Mei.
Zhen Zhen also contributed important data to our studies of panda hearing, mother-cub behavior, and infant development. Her ability to participate in the hearing study illustrated well just how smart giant pandas are and how quickly even a young bear can learn a challenging cognitive task. And the data we collected on Zhen Zhen’s behavior enhanced our understanding of the normal scope of cub behavior, even in light of distinct differences in temperament.
Some folks have wondered if Bai Yun will miss Su Lin and Zhen Zhen. I think our best answer to the question is to look to what we know of panda biology: panda mothers in the wild wean their offspring when the cubs are about 18 months old. At this same point, the panda mother and cub will part and begin their separate lives. For Bai Yun, I’m sure she’ll notice the eventual absence of the scent of Su Lin and Zhen, but she said her panda “goodbye’s” long ago. Unlike Bai Yun, we have all just said our goodbyes, and we will miss these bears!The news from China regarding the birth of Hua Mei’s eighth cub well illustrates the potential for Su Lin and Zhen Zhen to be important conservation ambassadors for giant pandas. Hua Mei’s prolific reproductive output is good news for giant pandas; although Bai Yun’s genes are well represented in the captive population, Shi Shi’s genes are not. Hua Mei is the only known offspring of Shi Shi, so each of her cubs contributes to the genetic diversity that is so important to the conservation value of Wolong’s giant pandas. And now Su Lin and Zhen Zhen have embarked on the same journey, and again, along with Bai Yun’s genetic makeup, they bring Gao Gao with them as well. Like Shi Shi before him, Gao Gao is also unrepresented in China’s captive population of giant pandas.
In the coming years, we will continue to observe the milestones in Su Lin and Zhen Zhen’s lives, albeit at a great distance. And of course, we will share what we learn with their great “panda family”: the Panda Team, San Diego Zoo visitors, and our large family of worldwide panda fans.
Update September 26: This morning, Gaylene informed us that the two pandas had arrived safely at their destination.