As the hour wore on, I noticed that she was not taking long rest periods as in days past. Instead, she would only rest for about 10 minutes before getting up to nest build or lick some more. I wondered if this would be a temporary restlessness or if this would build as the day progressed. At 8 a.m., keepers tried to get Bai Yun to cooperate with an ultrasound procedure. She walked voluntarily into the tunnel where we conduct the exams. However, it became quickly apparent that she was too restless to settle down and lay still, so the ultrasound was scrapped. Shortly after returning to her bedroom and sunroom area, I observed Bai Yun straining to defecate in the sun room. This occurred several times over the next hour. When she moved this straining to the den at about 9 a.m., I began alerting staff on site that Bai Yun may be in the early stages of labor.
As everyone gathered, Bai Yun continued to progress. She intermittently engaged in nest building, licking, and straining. The straining very clearly moved to obvious contractions, and after a few hours she began to grunt along with her contractions. We watched with baited breath, aware that this labor appeared to be taking longer than some of her previous ones. Bai Yun seemed to be lagging with fatigue.
At 2:10 p.m., with a loud squawk, a baby panda made its way into the world! Bai Yun was in a seated position when the cub emerged, and it never even touched the ground before she had it in her embrace. Bai Yun immediately comforted and consoled the cub, and it settled down quickly. Over the next hour, staff watched with relief as Bai Yun seemed to relax and enjoy a few short catnaps with the cub vocalizing intermittently to remind us all that it was still there.
We are so very pleased to have witnessed another wonderful birth. Despite the lengthy labor and the concerns we all had about the impact her age might have on her ability to sustain a pregnancy, Bai Yun has once again shown us that she is, indeed, a hero mother.
Suzanne Hall is a senior research technician for the San Diego Zoo Institute for Conservation Research.