White Rhino Births: What We Know and Don’t Know

Eight-Day-Old Southern White Rhino Kayode

Kayode, at 8 days old, frolics at the Safari Park.

For the first time in about 12 years, a newborn southern white rhino is running around at the San Diego Zoo Safari Park. His name is Kayode, and he’s a spunky little dude, charging the Cape buffalo with his mother, Kacy, following close behind. He’s a welcome, if not long awaited, addition to the herd. You might be wondering why there aren’t more calves like Kayode cavorting at the Safari Park? Why has more than a decade passed between southern white rhino births?

In zoos around the world this trend appears to be commonplace. Females brought in from the wild to establish zoo-based breeding programs have generally reproduced relatively well compared to females born in captivity. The reason why remains unclear. We suspect that most zoo diets contain plants that produce chemicals called phytoestrogens. During their 16-month gestation, female white rhinos could be exposed to these compounds through Mom’s diet, resulting in permanent fertility issues later in life. In many other species, exposure to phytoestrogens during gestation causes similar reproductive problems.

Notice the words I use here: appears, generally, relatively well, could be. Even coming from a scientist (a notoriously skeptical bunch), these statements do not inspire much confidence. That’s because this breeding problem is particularly complex, and solid data proving that captive-born females have a breeding problem, and that it is caused by diet, is hard to come by. Here are a few questions and answers demonstrating what we know and what we don’t know:

Q: Do captive-born female southern white rhinoceros have trouble reproducing?
A: It looks that way. Depending on the study, estimates of the percentage of captive- born females that have reproduced ranges from 10 percent to about 50 percent. However, a more thorough investigation of individual histories that may preclude reproduction needs to be conducted. In other words, determining if non-reproducers even had access to mates, were housed in properly sized enclosures, or lived in appropriate social groups will give a more accurate indication of the extent of the problem.

Q: Are phytoestrogens a possible cause of this phenomenon?

A: We think so, and we have data to support it! At the molecular level we know southern white rhinos are sensitive to phytoestrogens. We also know that many zoo diets contain phytoestrogens. However, we have not and likely cannot conduct the types of cause- and-effect experiments that could prove it, because that would require having many groups of rhinos eating diets with different levels of phytoestrogens and following reproductive success for multiple generations.

Q: Are there any dietary differences between institutions that have breeding success and those that do not?
A: Anecdotally, yes. At most institutions commercial pellets comprise a large proportion of diets, which we know contain high levels of phytoestrogens. At the four or five institutions that have the greatest captive-born female breeding success, diets appear to consist of mostly grass, and we are investigating to determine this for sure. We have not been able to detect phytoestrogens in grass samples from one of the more successful institutions. Interesting for sure, but not quite a smoking gun.

I hope you can appreciate what we’re up against. As we work toward a solution, we continue to find pieces of information that alone do not meet the burden of proof but together they continue to build a case for phytoestrogens causing reproductive harm in captive-born females. We still have a long way to go, but one day I am certain we will have an answer. In the meantime, come see Kayode and learn for yourself why his name means, “he brings joy.” While you are watching him, consider this additional piece of information that I neglected to mention. Kayode’s mother, Kacy, just so happens to have been born at one of the institutions that feed their rhinos primarily grass. Now THAT’s pretty interesting!

Christopher Tubbs, Ph.D., is a scientist in the Reproductive Physiology Division of the San Diego Zoo Institute for Conservation Research.


Rhino Poaching Increases at Alarming Rate

Eastern black rhino mom and calf

Below are wild rhinoceros population statistics compiled by the Traffic Wildlife Trade Monitoring Network. The numbers are so appalling that we thought we’d share them with you to raise awareness and garner support for the dire plight of rhinos. We hope you’re as shocked and alarmed as we are and even more dedicated to fighting for the survival of this important species.

  • Combined black rhino populations = 4,838 animals – IUCN listed as Critically Endangered
  • Southern white rhino populations = less than 20,000 animals – IUCN listed as Near Threatened
  • Combined Nepalese and greater one-horned rhino populations = 2,913 – IUCN listed as Critically Endangered
  • Javan rhino populations = less than 50 animals – IUCN listed as Critically Endangered
  • Sumatran rhino populations = less than 200 animals – IUCN listed as Critically Endangered

Rhino poaching stats from South Africa

  • 2009 = 122 animals
  • 2010 = 33 animals
  • 2011 = 448 animals, including 19 black rhinos
  • Poachers arrested in 2010 = 165
  • Poachers arrested in 2011 = 232

Source: http://www.traffic.org/

Help us spread the word that poaching needs to stop. Re-tweet this tweet:

Matt Steele is the social media planner for San Diego Zoo Global. Read his previous post, Rhinos: Never Give Up, Never Surrender.


Collecting Rhino Treasures: Poop!

Two of the Park's greater one-horned rhinos on the prowl for food.

What’s the equivalent of having a case of the “Mondays” as a zookeeper? How about accidentally throwing poop out of the truck window and being disappointed about it? Yup, this was my day last week. My job at the San Diego Zoo Safari Park is anything but typical, and the mishaps are always out of the ordinary. When you ask a keeper how his or her day was, be prepared—we don’t hold back! You never know what kind of gory details we’ll share with you.

Once a week, we strategically collect fecal samples on all five greater one-horned rhino females and submit them to the San Diego Zoo Institute for Conservation Research for hormonal analysis. These samples are really hard to get, but they provide tons of information about the rhinos’ reproductive patterns and help us determine which is pregnant, and when we should expect a baby rhino! (See Rhinos: Sounds of Romance.)

It may sound crazy that these samples are so hard to come by. Rhino poop is huge, and there’s a lot of it, but there’s a trick to collecting a single sample from a group that uses a communal dung pile. This pile is called a midden, and rhinos use it as a message station; they investigate the pile and then defecate in the same spot. While doing this, they root through the pile with their horn, scrape their hind feet, and then spread scent by walking through it and dispersing it with their feet.  The Safari Park rhinos use a midden, and they often line up and defecate one after the other. If you’re not on your game, it can be impossible to identify and collect even just one sample, let alone all five female samples, from this group of seven rhinos.

The ill-fated fecal samples in the rhinos' carrot bucket

Anyway, I was on a roll collecting samples. The group had spread out in the exhibit, so I was guaranteed to get samples from at least a few of them, if not all five that day. I already had two, and without thinking anything of it, I put the small sample cups into a bucket of carrots in the passenger seat, like I usually do. I spotted the other rhino girls across the exhibit and hurried over to them. I pulled up to a midden and called them to the truck. They walked over and some of them went to the pile while the rest came over and ransacked my truck! They yanked feed bags off the back, stole food from the tubs of goodies, and tried to stick their heads in the windows!

One of the younger girls, Sundari, investigated the pile and provided a sample. Great! I was ready to drive closer and pick it up before another rhino could ruin it, but first I had to get the rest of the rhinos away from my truck so I could drive. Instinctively, I grabbed a handful of carrots from the bucket and carelessly threw them out the window for the rhinos to chase. Greater one-horned rhinos love food, and this method usually works, but as soon as the carrots went sailing off into the exhibit, a small plastic cup caught my eye—I had tossed the sample right out the window with the carrots! Shoot! It landed only a few feet away, but I was surrounded by thousands of pounds of rhinoceros. I had no choice but to stay in my truck. I decided to maneuver the truck into position right over the sample cup to protect it.

The rhinos seemed particularly hungry that day and weren’t falling for my scattered carrot trick; they chose to feed from the truck buffet instead. Hmm. I had to get more creative, but as I was brainstorming, Bhopu, our 10-year-old male, lumbered over to the midden and began to…poop! He was ruining Sundari’s sample. I had to make a snap decision: stay and protect the sample under my truck or get closer to the midden to retrieve Sundari’s sample.

I figured the tiny sample cup wouldn’t attract much attention, so I momentarily abandoned it attempting to save Sundari’s sample. I sped forward and heard a crunch—oops! Oh well; I was committed, so I proceeded to the midden. Unfortunately, I was too late. Bhopu ruined Sundari’s sample, and I had driven over the other one. I was defeated by a bunch of hungry rhinos and my own uncoordinated efforts.

The rhinos grew bored with me and wandered away. I got out to retrieve the squished cup, and ta-da! Those cups are pretty tough; the cup was broken, but the sample was fine. All was not lost. Now, on with the rest of the day!

Whew! And that was just my morning.

Jonnie Capiro is a keeper at the San Diego Zoo Safari Park.




Black Rhinos: Lots of Attitude

Our black rhino mother, Lembi

The San Diego Zoo Safari Park is home to three of five rhinoceros species. All are huge and endangered, but one has a reputation for a whole lot of attitude! The eastern black rhino Diceros bicornis michaeli is the Park’s smallest rhino species, but they are also the most aggressive. This is evident when you see the black rhino enclosure separate from the mixed-species field exhibits we are known for. These rhinos can have quite the temper and are extremely territorial, so for the safety of the rest of our animals (and keepers!), the black rhinos have a home all to themselves. The Park is currently home to four black rhinos: Jambia, Lembi, Belozi, and Erik.

Jambia is our adult male weighing 2,363 pounds (1,055 kilograms), and his name means “dagger” in Arabic. He was born here on February 25, 1997, and was hand raised in our Animal Care Center by some very loving rhino “moms.”  Yet that attention did not soften his preprogrammed demeanor as an adult. To feed and clean his enclosure, keepers must first move him to another section of the compound; the last time we drove a truck into his home, we were quickly cautioned to not attempt this invasion again! If you look closely at the keeper trucks the next time you see them drive past, you might notice a truck with two ugly holes in the passenger side, a lasting reminder of this well-learned lesson.

Lembi is our female black rhino. Born at the San Francisco Zoo on July 16, 1998, she moved here in July 2000. She is a great mother and has given birth to four calves, all fathered by Jambia. At 2,557 pounds (1,160 kilograms), Lembi is, thankfully, tolerant of trucks in the enclosure as long as we don’t dillydally in getting the food out to her! She is also involved in a new training program and is responding very well to the experience, learning to touch her nose to a target and to open her mouth on command; we soon hope to begin work on blood draws and ultrasounds. All of these behaviors will lessen the need for anesthetic during many health assessments.  We work with her in what we call a protected-contact environment, meaning there is always a safety barrier between the keeper and the rhino.

Lembi is being closely followed at all times by her year-old calf, Erik. He was born on July 19, 2010 (see post, Black Rhino Calf!).  Even though he already weighs approximately 900 pounds (410 kilograms), he is the biggest baby you have ever met: he never strays more than about four feet from his mother and utters a high-pitched cry if she ventures off without him noticing. We are working very closely with Erik to have him become comfortable taking food from our hands and to condition him to a training chute. At the moment he is doing great, so long as his mother is close by (usually in a training session herself), but if we separate them he still gets pretty agitated. We are moving slowly toward the goal of working with each of them independently, since Lembi often sees that her son has dropped a few biscuits, and what kind of a mother would she be if she didn’t just clean those up for him? As you can imagine, this is very disruptive to both training sessions!

Belozi, whose name means “ambassador,” is Erik’s big brother; unfortunately, there will be no brotherly loved shared here. In a rhino’s world you have your mother’s undivided attention and love until she has a new baby. Unlike most families I know where a new baby means all kinds of toys and special bonding time for the older child, in rhino society this arrival means that you get to practice all of the skills your mother taught you because now you are on your own! In the wild, an older calf might try to follow Mom for a while longer, but usually they are chased off if they get too close. There seems to be an unspoken “one calf at a time” rule for rhino mothers. Knowing that Lembi would not be happy with Belozi’s continued presence after Erik was born, they were separated about two months before Lembi gave birth. Belozi is living the solitary life normal for a rhino in an off-exhibit area of the Park until he moves to another zoo to start a family of his own.

Although Jambia and Lembi have been very successful parents, they are getting a break at the moment. Black rhinos are part of a Species Survival Plan (SSP), and breeding is based on international recommendations that take into account housing availability and genetics. With four sons to pass on their genes, the SSP feels that this pair is well represented, so Lembi and Jambia are being housed in different areas of the black rhino compound. Make sure to take a moment to look into the exhibit from the Africa Tram Safari the next time you are visiting the Park and see who is out that day!

Kym Janke is a senior keeper at the San Diego Zoo Safari Park. Read her previous post, All about Antlers.


The Dirt on Rhinos

Laura gives Soman and Surat some attention.

Soman and Surat, our greater one-horned (Indian) rhino brothers have been busy growing and practicing to become adult males. They still have quite a few years to go. Along with feeding, training, and maintaining their health, as keepers we also need to keep their exhibit in great shape. As you can imagine, this means a large amount of heavy lifting. We rototill the exhibit monthly to keep the dirt nice and soft for the rhinos’ feet.  Maintaining an exhibit that large takes a lot of time and work; sometimes we need a little help.

At the San Diego Zoo, we are lucky enough to have thousands of members and others who care very much about our animals. They take an interest in their daily lives and want to know every detail. Some do this by visiting the Zoo every day, while others visit our Web site from all across the world. They are always asking what the animals need or what they can do to help. Sometimes all our animals need is some dirt. Sounds like a small request, but when you have a huge exhibit with two big rhinos, it’s A LOT of dirt.

Some generous donors wanted to provide fresh dirt for the rhinos. We use special dirt in the animal exhibits, depending on the species and where the dirt will be going. This dirt was mainly to fill in some low areas and make a big pile for the rhinos to play in. To deliver it, a huge tractor trailer drove into the exhibit and dumped the dirt right at the top of the yard. Then we used machinery to move the dirt to the appropriate places. We made sure to leave a big pile for the boys to play in and sit on. This process helps to keep their feet healthy and their minds active.

When we released them into the exhibit, they were so busy smelling all of the new dirt and enjoying the feeling. Soman laid down near the Backstage Pass area, and I swear he was snuggling with the dirt. He was rubbing on the ground like a dog in a comfy bed. They also have a great time playing in the dirt pile, taking turns pushing each other off so they can stand on top—kind of like playing “rhino of the mountain.” They dig their horns into the dirt and fling it high up in the air. So much fun!

As keepers, we thank the donors who care about our animals and do whatever they can to help. It makes our job even more rewarding.

Laura Weiner is a senior keeper at the San Diego Zoo. Read her previous post, Camel Tuya Moves Out.


Get a Backstage Pass

Meet our newest star in training: a cheetah cub!

Meet our newest star in training: a cheetah cub!

Have you ever wanted to ask a rhinoceros how sensitive its skin is? Or have you ever wanted to ask a cheetah why it has spots and not stripes? Or maybe you want to ask a ground hornbill how to properly catch a snake? Well, in all honesty, you can ask them all the questions you want, but you may never get an answer. That is, until now.

You'll meet several animals close enough to touch!

You'll meet several animals close enough to touch!

The San Diego Zoo’s Backstage Pass offers a unique experience to get up close and personal with some of the animal ambassadors and stars of the Zoo. Of course, the animals can’t answer your questions themselves, but we have found the next best thing! The trainers, handlers, and keepers who work with these amazing creatures every day are right there to answer your questions. You can ask them all about the species of animals they work with. And you’ll be amazed by some of the unique adaptations of the animals as well as the personal connection the trainers have with them.

Give our rhino some VIP treatment!

Give our rhino some VIP treatment!

But it doesn’t stop there! Part of the experience is a delicious picnic meal. While sitting down and enjoying the tasty food, someone might be picked from the group to help a trainer demonstrate how we train animals. I won’t spoil it for you by telling you ALL the details, but just know you are going to have a lot of fun watching how we communicate with our animals using positive reinforcement.

Enjoy a private animal show!

Enjoy a private animal show!

The overall experience takes about two hours, and I have to admit, when I was there I had so much fun I couldn’t believe how quickly those two hours went by. But keep in mind the perks of this VIP experience don’t stop there. For the entire day, when you show your VIP “Backstage Pass” lanyard, you will get seated in the reserved seating section at all of our shows and you will also get priority loading on our bus tour if you have a bus ticket or Best Value admission ticket!

It sure feels good to be a VIP at the San Diego Zoo!

Rick Schwartz is the San Diego Zoo’s Elephant Odyssey Ambassador.

Here’s more information about the new Backstage Pass program

Watch video of Backstage Pass


Rhino Brothers Form Attachment

Surat is the one standing in this photo.

Surat is the one standing in this photo.

Soman and Surat, our two Indian rhinoceros brothers, are doing great on Elephant Mesa at the San Diego Zoo (see Laura’s previous blog, Adventures in Rhino Keeping).

Surat has become attached, literally, to Soman. He follows behind Soman wherever he goes. It is quite cute but posed a problem for behavioral management. First we started separating them in the barn during the morning cleaning. Normally we would come into the barn and see them resting next to each other in the same barn. At first we would close the door in between them for a couple of minutes to observe their behavior. Soman didn’t seem to care that he was alone, but Surat was definitely agitated. He would bang his head (a normal rhino behavior) against the door, trying to get back to his favorite friend and brother. We chose to ignore this behavior and only put them back together when they were both calm. After a few days, they were separated during the cleaning time and given some of their food in their respective barns. It took about a week for Surat to realize that all of the banging in the world would not get him back with his brother. He has since begun to quietly eat his pellets and wait until they are both let out onto exhibit together.

Surat is the one standing in this photo as well.

Actually they are doing so well that I have been working with them and some other trainers to separate them a couple of times each day. You never know when you will need to medicate an animal or perform a veterinary procedure. It is always nice to be able to separate animals in a non-stressful way. My new goal is to separate them on exhibit so each can learn behaviors. I tried working behaviors with both at the same time, but they would just push the other out of the way to get more treats. I recruited another keeper, Lindsey, who had just transferred from the Wild Animal Park. We have been working on walking them around the exhibit, each one of us taking a rhino, holding one in place while the other walks, and even having them walk around one another. (We don’t actually go in the exhibit, of course, but walk along the back fence and have the rhino follow along.) They are both learning to come when called but still need to work on their focus. Both Surat and Soman see us as treat suppliers and will go to whoever is closest. But they have been improving rapidly and every day we switch things up to keep them on their toes.

Best of all, Surat finally realized that a belly rub is a good thing. For a while he would barge in on Soman and get in the way of the brushing session. Now Surat will stand still and raise his tail just a few inches (this means a happy rhino) while enjoying the attention.

Laura Weiner is a senior keeper at the San Diego Zoo.