Bai Yun continues to progress toward her birthing window in a predictable fashion. Part of this progress means she is “denning up” in preparation for the birth. Over time, she is spending more and more time in the den resting, eating, and nest building inside. In the last 24 hours, she spent 680 minutes (over 11 hours) in that den, but soon enough it will be 1,440 minutes (a full day!).
For now, when she is not in the den, she can typically be found sleeping just outside the den entrance. She no longer makes trips out to the large outdoor space she had available, so the keepers have closed off that area. She has even stopped visiting the garden room and resting atop the platform there. From this point forward, it’s den, bedroom, and sun room…but increasingly just den.
We can’t tell you exactly when Bai Yun will give birth. We can say that all signs point to early August. Our various signs and indicators do have some predictive value for us: How far out did she reduce her bamboo intake? When did she begin spending time in the den? What do the fetal measurements tell us about how developed the cub is? I can tell you that all of these factors are aligning nicely with regard to a predicted birth date, all pointing to windows within a few days of each other. There is enough variability, however, that we won’t be brash enough to predict for you exactly when the cub will be born. You could say we are watching her overnight…
Cub, not cubs. Did I mean to type that? We have good evidence that one cub (gestating in the right uterine horn) is developing beautifully. You may have seen it on the ultrasound pictures, curling its head and moving its paws. The vets have been able to see mineralization of the bones and tiny claws. This cub looks strong and healthy so far. What about its twin?
Last week we saw a heartbeat from the cub in the left uterine horn. It looked smaller and less developed than its sibling. Since that heartbeat sighting, we haven’t had a chance to see Left Cub. We have not seen its heartbeat stop or its placenta degrade as Mei Sheng’s uterine roommate did in 2003. But staff is becoming increasingly suspicious that Left Cub will not survive the pregnancy.
If this makes you unhappy, you’ll have to take it up with Bai Yun. This is her call. But you’ll have to wait for some time, because it looks like she’s going to be busy for the next few months!
Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.