On January 20, 2012, a female greater one-horned rhino female was born at the San Diego Zoo Safari Park. Exciting news! But let me tell you how we prepared the first-time mother, Alta, for the birth and why this kind of surprise isn’t out of the ordinary. Last summer we learned from our research team that seven-year-old Alta was pregnant. We submit routine fecal samples (See post Collecting Rhino Treasures: Poop!) and monitor any kind of breeding activity to track a pregnancy. We were excited, because this would be Alta’s first calf and our second calf from the genetically desirable male, Bhopu. We looked at our detailed breeding records and started devising a birth management plan.
Gestation is typically 15 to 16 months for this species, but determining a due date involves some data and scientific background. We are not out in the field 24 hours a day, and those rhinos engage in all kinds of activity when we are not on duty. There are many variables that can confuse things, such as misleading estrous behaviors observed during pregnancy, and it can get quite complicated! We take all of these challenges into consideration when speculating about potential due dates and use these as milestones. Our overall plan is to make sure that any rhino moms-to-be are checked into their maternity suite, called a boma, in plenty of time to acclimate to the new surroundings. The maternity room is padded with bedding that ensures a safe delivery away from the immense and somewhat uneven terrain of the Safari Park’s field exhibit. Because this was to be Alta’s first calf, we moved her into the boma (a fenced-off area within the exhibit) months in advance for a few days at a time to get her used to being away from the group and to become adjusted to the boma and its maternity room.
At first, Alta was wary of being in the boma, but as time progressed, and she realized it was a nice place to relax for a couple of days, her typical behavior returned. Imagine trying to convince a rhino that this change is for her benefit. We can’t tell her not to worry, that we have a team of very experienced veterinarians in the event of a complication and that the keepers will carefully monitor her calf for any signs that we need to intervene. Instead, we convinced Alta as only keepers know how, with positive reinforcement! We made a positive association with the boma by providing big rhino enrichment toys, big and leafy ficus branches (a rhino favorite), and lots of attention! She came to accept the boma as a place to rest, and she seemed more comfortable after several of these “practice runs.”
When Alta began to have some teat development, she was moved her into the boma for further evaluation of her behavior, appetite, and physical development. That was a couple of weeks ago, and she really wasn’t showing much progress. She was calm, eating well, and didn’t seem very restless. We referred to our records again, and saw that the next possible due date wasn’t until March. That was so far from now! But that very same day, while we were observing her and discussing our plan, a flash of pink skin just beneath her belly caught our attention—she appeared to be having further teat development. It looked bigger than it did a few weeks ago. That was enough information for us to be confident that we needed to keep a close eye on her.
The next day, she demonstrated more signs of an impending birth, and we started a 24-hour watch. Just after midnight on January 20, under the careful watch of a keeper, the calf was born, and Alta’s instincts kicked in. She cleaned up the baby and allowed her to nurse. This is one of the most important behaviors we need to observe, just to be sure that this first-time mom has figured out her role. We continued the observations throughout the following day, noting her progress, behavior, and amount of time she spent nursing. Everyone felt comfortable that this birth was a success!
This birth is also a big step toward contributing new genetic material to the managed population of greater one-horned rhinos in the United States. This species is considered “vulnerable” in its natural habitat, with a small population of about 2,850 rhinos in India and Nepal. This was the 61st greater one-horned rhino born at the Safari Park—great news for this species! I’ll share more news about the calf next week.
Jonnie Capiro is a keeper at the San Diego Zoo Safari Park. Read her previous post, Ready for a Rhino Relationship.