San Diego Zoo’s Institute for Conservation Research


One More Thing Before They Go

Su Lin

For the past year, Su Lin has been the primary subject of our giant panda hearing study. About six months ago, Zhen Zhen began her participation in earnest, and for the last two months, she has been showing us what a three-year-old panda can hear. Data that we’ve collected from both of these bears are unprecedented and mark the first glimpse into the auditory world of the giant panda.

While keepers are working hard to make sure Su Lin and Zhen Zhen are ready for their upcoming adventure and transition to life at the Bi Feng Xia base in Sichuan, China, our research team is also working hard collecting every last scrap of data we can on this pair! Our hearing study requires a collaborative effort between researchers, keepers, and bears, and very few other facilities anywhere in the world have the combination of resources that allows the pursuit of such research. We are very proud of our collaborative efforts and are going to miss working so closely with Su Lin and Zhen Zhen.

We began the hearing study on giant pandas about two years ago, with Bai Yun as our main subject. In the month before she gave birth to Yun Zi, Bai Yun decided that she wasn’t interested in our research anymore! Of course, we obliged her desire to be left alone and shifted our focus to Su Lin; she showed us her hearing was perhaps even more sensitive than that of her mom. Over the course of the last year or so, we have been able to collect a lot of data on Su Lin and, when our analyses are complete, we should be able to produce a comprehensive description of panda hearing—an unparalleled achievement.

Unfortunately, we haven’t had as much time to work with Zhen Zhen, but we have been able to pinpoint some important frequencies to test, and her data will make a very interesting comparison: Zhen Zhen’s young ears are in perfect shape, but are her listening skills as sharp as her older sister’s? Again, when the analyses are complete, we’ll have more answers.

Over the next week or so, we will work with Su Lin and Zhen Zhen as much as we can. The data are, of course, important, but the time the keepers and researchers get to spend with the bears is something to cherish.

After Su Lin and Zhen Zhen leave San Diego, we will reintegrate Bai Yun into the study and incorporate Gao Gao as well. Gao Gao has been working with keepers and getting ready to be a part of the study for some months now, and we are all looking forward to having a chance to work with him and study his ears as well.

Megan Owen is a conservation program specialist for the San Diego Zoo Institute for Conservation Research. Read her previous post, New Chapter for Su Lin, Zhen Zhen.


Our Good-bye Girls

Zhen Zhen

I have read with some sympathy the many, many comments, questions, and concerns you have posted in the last few days in response to news that our two youngest girls are heading back to China very soon. I wanted to take a moment to address some of the issues you have raised and offer further insight into this important transition for Su Lin and Zhen Zhen.

Currently, both girls are undergoing another transition, from biscuits to bamboo bread. The bread is what the bears are fed in China, and to minimize the stress of the move, we want them acclimated to this dietary change as much as possible before they leave. Thus far, little Zhen Zhen is taking to the bread with a little more enthusiasm than her big sister.

When the bears are transported, they will not be sedated for the journey. This is the primary reason for crate training; once the crate is a familiar environment, they will enter it willingly and be comfortable when inside. A seasoned and familiar handler will travel with the bears, and job one will be to keep the girls calm and happy. Experience has shown us that supplying copious amounts of fresh bamboo during the flight goes a long way toward making this a successful voyage.

The other bears we have returned to China have been great successes: Hua Mei has been a twinning superstar, and as a result, she has given birth to more cubs than her mother; Mei Sheng was the youngest male on record—at less than five years of age—to copulate with a female. Mei Sheng participated in the 2010 breeding season and stands a good shot of being a daddy this year. I am sure Su Lin and Zhen Zhen will also do well in their native land.

The loss of our girls has another silver lining beyond those mentioned above: Gao Gao will make a return to the exhibit areas in fairly short order. Due to our need to house Su Lin up front in order to facilitate the hearing study, our patriarch has been behind the scenes for many months, and I know he has many fans that would love to see him again.

I appreciate your bond with our panda youngsters. Those of us who work with them are not immune to their charms. So much of our lives—and our time—is invested in these animals. That they would leave us one day was understood. That they will make us proud is inevitable.

China has embarked on a new plan to release pandas to the wild, one in which captive-bred females will give birth to their young in a semi-wild enclosure, and those unadulterated cubs will grow to be wild bears that will live their whole lives outside of the breeding center. Someday, one of Gao Gao’s descendants may wander the mountain passes of the Wolong Reserve. That would truly be a great end to the story begun in San Diego.

Suzanne Hall is a senior research technician for the San Diego Zoo Institute for Conservation Research. Read her previous post, Bamboo Feeding Basics.


New Chapter for Su Lin, Zhen Zhen

Su Lin

When Bai Yun and Shi Shi arrived in San Diego from China in September 1996, the San Diego Zoo made it clear that it was committed to giant panda conservation. Bai Yun and Shi Shi captured the public’s attention, and the problems we encountered trying to get this mismatched couple to breed mirrored the predominate conservation problem that researchers were trying to tackle at facilities in China: How do you get giant pandas to breed in a captive setting? How do you get pandas to do what should come naturally?

Over the next 10 years, our interdisciplinary panda team worked tirelessly to study all aspects of reproduction, apply what we learned to the pandas at the San Diego Zoo, and develop a two-way exchange of knowledge with our partners at the Wolong Breeding Center in Sichuan, China. In 1996, only two females gave birth at Wolong. Although captive breeding was only one component of the conservation puzzle, it was clear that without a self-sustaining and genetically diverse captive population, the ultimate goal of reintroducing pandas to the wild would never come to fruition. But how quickly things have changed!

By the time I traveled to Wolong for the first time in the winter of 2000, the breeding center was enjoying a record-setting number of recent giant panda births (11 cubs!), and the San Diego Zoo’s Hua Mei, conceived through artificial insemination, was charming Zoo visitors and giving us a lot to study in the realm of panda cub development. The studies of panda behavior, reproductive physiology, genetics, and animal husbandry had all come into play to support the success at the San Diego Zoo, as well as at the Wolong Breeding Center.

Over the years, we (the Zoo’s Panda Team, visitors to the Zoo, and panda fans) have developed an incredible connection to and love of the pandas that have been born and raised in San Diego. Hua Mei’s departure from the Zoo marked our first experience with sending a San Diego-born panda to China. She was followed by Mei Sheng in 2007. Although we all knew it was for the best, it was a tough pill to swallow, and Hua Mei and Mei Sheng were sorely missed. Looking back now, however, with seven cubs representing Bai Yun and the completely unrepresented Shi Shi’s genetic make-up, we are very, very proud to have contributed to the broader needs of giant panda conservation.

Zhen Zhen

Soon, both Su Lin and Zhen Zhen will follow in older siblings Hua Mei and Mei Sheng’s footsteps. As I write this, I can tell you that I will miss these two bears! Su Lin is five years old, has already experienced her first fully developed estrus cycle, and is more than ready to join the conservation breeding program at the Wolong Nature Reserve Giant Panda Bi Feng Xia Base. Zhen Zhen is three years old now and will embark on her panda adolescence as part of the panda program at Bi Feng Xia as well.

Both Su Lin and Zhen Zhen have made incredibly valuable contributions to our research program and have contributed ground-breaking data on panda hearing sensitivity. These data will allow us to better estimate how noise from human activities may impact giant pandas in the wild. Collecting these data allowed keepers and researchers to work with both of these beautiful bears, up close and personal, on a daily basis. What a pleasure that has been!

As the drive to learn conservation-relevant knowledge of giant pandas shifts from captive propagation to reintroduction, we are excited that the pandas of San Diego will become a part of this larger conservation effort. Who knows? Maybe in the not-too-distant future, one of Gao Gao and Bai Yun’s descendants will one day be born in a large, old-growth tree den high in the mountains near Wolong. That image alone is enough to bring a smile to my face and makes me truly feel that the Giant Panda Team, and supporters of the San Diego Zoo’s pandas, have much to be proud of.

In preparation for their new adventure, Su Lin and Zhen Zhen will not be in public view beginning Monday, August 16, while they continue a training program that helps prepare them for the changes ahead. Their mother, Bai Yun, and her one-year-old cub, Yun Zi, will continue to be seen at the San Diego Zoo.

Megan Owen is a conservation program specialist for the San Diego Zoo Institute for Conservation Research Read her previous post, Birthday Celebration.


Seeing Red: Biodiversity at Risk

Sun bear cub

The primary purpose of The San Diego Zoo Institute for Conservation Research is to generate, share, and apply scientific knowledge vital to the conservation of animals and plants. Unfortunately, there are many species in need of this kind of attention, as the loss of biodiversity worldwide has reached crisis proportion. We may all be aware of this from media reports, but how do we actually know what the state of global biodiversity is? Who organizes and synthesizes this information on the world’s many species?

While there are many organizations that lend expertise to this process, the largest overseer of work related to the conservation of biodiversity is the International Union for Conservation of Nature (IUCN). The IUCN is the world’s biggest global network of scientists, governments, and non-governmental organizations (NGOs) working to promote the conservation of nature through research and restoration, development of laws and policies, and providing supportive resources where needed.

The IUCN is also responsible for the development of the Red List of Threatened Species, a comprehensive assessment of the conservation status of species on earth. It is the Red List that tells you that the giant panda is endangered, but the brown bear is not. You can view the Red List here.

This year, to increase awareness of biodiversity, the IUCN is providing daily fact sheets on target species on the Red List. Every day, you can download a new “Species of the Day” fact sheet that will tell you about a particular plant or animal and its conservation needs. Some of the species may be familiar to you, such as polar bears, while other species are more unusual (like the Luristan newt, a critically endangered salamander from Iran). In each case, you have an opportunity to learn, from a leading authority in the field, about species representing a piece of the puzzle of life on earth.

On Thursday, July 15, the Species of the Day is the sun bear. This bear is classified as vulnerable to extinction, and is one of the primary foci of our work on maternal care in bears. Sadly, this species is facing tremendous pressure from habitat loss, a primary reason for its decline. I invite you to click here to learn more about sun bears from IUCN.

There, you can also find an archive of all the 2010 Species of the Day thus far. Let this list inspire you to change, in order that these species might endure into the future.

Suzanne Hall is a senior research technician for the San Diego Zoo Institute for Conservation Research


Andean Bears: Two Steps Forward

The dry forest landscape in what is now part of El Parque Arqueológico y Ecológico de Batán Grande.

I’m pleased to report that there have recently been two tangible steps forward for the conservation of Andean (spectacled) bears and the tropical dry forest in northeast Peru, where we’re working with our collaborator, the Spectacled Bear Conservation Society (SBC). (Read post In It for the Long Haul.) In fact, both advancements involved SBC either directly or through collection of data and outreach resulting in greater community and governmental interest in conservation.

In chronological order, or first things first, here’s what’s happened:

First, the Peruvian government announced the creation of El Parque Arqueológico y Ecológico de Batán Grande to conserve both ecological and cultural (archaeological) resources in northwest Peru. This park was simultaneously created and recognized by numerous levels of the Peruvian government, ranging from the local municipal district to the relevant cabinet-level ministry. One of the primary catalysts for the creation of this park, especially at this time, was the knowledge generated through our collaborative effort with SBC.

Second, SBC has opened a center for conservation outreach and investigation in the town of Batán Grande. The town is closest to our main study site in the dry forest, and this conservation center will be used for conservation education activities by local school groups, research presentations to the public, and meetings with local community members.

Russ Van Horn is a senior researcher for the San Diego Zoo’s Institute for Conservation Research. Read his previous post, Unmistakable in English, Spanish, or Quechua.


A Bit about Breeding

Yun Zi, a happy result of natural breeding.

Recently, the Zoo Atlanta female panda experienced estrus, and some of you asked questions about the merits of artificial insemination versus natural mating. I thought I would take the opportunity to answer some of your questions here.

Bai Yun did not experience an estrus this year because she is still caring for Yun Zi, now 10 months old. The typical inter-birth interval for wild pandas is known to be two to three years. In the time between birth, a female is lactating to support the growth of her cub, and lactation suppresses estrus. This makes good sense, in that it would not serve a cub that cannot yet survive exclusively on bamboo if its mother were to become pregnant again and go through the denning-up process before a birth. This would leave a vulnerable, dependent cub out in the cold and reduce its chances of survival. Thus, in pandas as in many mammals, lactation by the mother precludes an estrus for a time.

Once estrus occurs, bears in captive breeding centers have two potential options for inducing pregnancy: natural mating or artificial insemination (AI). Natural mating is the preferred method, because it is more reliable in producing pregnancy. The males seem to know best when to time their copulations with the females, and perhaps fresh sperm from a male in these circumstances is more likely to get the job done. AI, which has produced Hua Mei and three cubs between National Zoo and Zoo Atlanta, obviously does work. However, despite these successes, there are more stories of failure of AI to result in pregnancy. For example, the procedure was done on Bai Yun in 1998, 2001, and 2002, to no avail.

In China, they often naturally mate a female with a male and then also perform AI with the sperm of a different male. When researchers did paternity tests on bears born before 2002, they found that in nearly every case, a cub’s father was determined to be the male that had naturally mated. Thus, despite the prevalence of AI as a technique in captive propagation of rare species, for some animals there is just no substitute for good ol’ fashioned male-female canoodling!

An interesting aside: bears that have more than one cub in their litter might just have more than one father for the litter. It is well known that female pandas, as with other bears, can mate multiple times during an estrus. Further, a female might find herself surrounded by many males at the peak of her estrus. This gives her the opportunity to mate with more than one male during her period of receptivity. Although I know of no case in pandas where multiple paternity has been confirmed for a particular litter, it has been confirmed in American black bears.

Zoo Atlanta has had great success with their AI process in recent years, and we are hoping their trend holds in 2010 as well. It would great to add another U.S.-born panda to the population!

Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.


A Genuine “Thanks” to Species

At the San Diego Zoo’s Institute for Conservation Research, and at the Zoological Society of San Diego as a whole, we spend our days working to save biodiversity. But the truth of the matter is that biodiversity is saving us. One of the founding fathers of conservation biology, and my own personal hero, Edward O. Wilson, perfectly articulated this connectedness and dependency in his classic 1987 lecture entitled “The Little Things that Run the World.” During this moving speech in Washington, D.C., Dr. Wilson depicted a world where humans suddenly moved on and the planet worked to heal itself after millennia of abuse. He argued that the world would heal relatively quickly once humans were gone, but that if the opposite were true, if invertebrates, for example, disappeared from the planet, that the whole of the human race would likely perish within a few months. Trained as an arthropod biologist, I am an easy convert for Dr. Wilson’s message; I already have a deep love and respect for the “little things,” but I’ve made it my life’s work to deliver his message to others.

Now I’m sure you need not be convinced of the importance of biodiversity. Especially from an intrinsic perspective, we value all life on Earth for its beauty, for its immense impact on our cultural traditions and spirituality, for its proven psychological and health benefits. But it is for its more essential, tangible benefits to humans that we absolutely must value biodiversity. Scientists and philosophers alike classify these benefits into two main categories: ecosystem products and ecosystem services. Ecosystem products are the myriad of invaluable resources provided to us by other forms of life on this planet, products such as food, medicine, and raw materials. Ecosystem services, by contrast, are the non-replicable processes and functions that other forms of life afford our species, services that are absolutely essential to human civilization but that are often considered “free” and taken for granted, services such as pollination, soil formation, waste treatment, gas and water regulation, prevention and mitigation of natural disasters, and nutrient cycling.

I am very proud to work for the San Diego Zoo. I am given the opportunity, almost daily, to spread awareness about the incredible brilliance, importance, and staggering loss of biodiversity. We are using the best science available to restore and take care of biodiversity as it takes care of us, and we’re also learning from its proven genius, asking the question, “What would nature do?” As we face increasingly complex challenges with society, industry, and the environment, we are looking to other species for ideas and solutions on how to address some of the most pressing issues of our time. In this way, we acknowledge and embrace our dependence on biodiversity and regard it as our ultimate teacher. This process of gently borrowing ideas from nature is also referred to as biomimicry, and it will prove critical to our goal of inspiring people to respect and nurture biodiversity as our most important caretaker.

Maggie Reinbold is a conservation program manager for the San Diego Zoo’s Institute for Conservation Research.

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Sun Bears: Weaning Options

If you are a San Diego Zoo member, you have already received your copy of June’s ZOONOOZ magazine. Our sun bears are highlighted this month, with sun bear dad Dibu on the cover! Flip through the pages, and you will see photos of Marcella and her offspring Palu and Pagi, and watch video of them, too!

Although we miss Pagi, who is reportedly doing well in her new home at the Oakland Zoo, life goes on in our Sun Bear Forest. Marcella and Palu are back out on exhibit, and you can see them daily (see Sun Bears: Up in the Air). Palu, in particular, seems very happy to be able to climb, explore, and stretch his limbs again. He’s still a growing boy, and very active.

We haven’t yet developed a plan for weaning Palu from his mother. Certainly he is of an appropriate age to be weaned, and obviously Pagi has already moved on to a new stage of independence. However, Palu’s situation is different from his sibling in that he is not yet slated to move to another facility. If we separate him now, he would remain at the San Diego Zoo in the near term, and that presents some challenges for us.

Those of you who have visited our Zoo know that we have a very robust population of bears. We are one of the few zoos in the world that has six species of bears exhibited: pandas, polars, brown, Andean, sloth, and sun bears. Bear Canyon is pretty full, and we don’t have any open, unused, bear-friendly exhibits to move Palu to. That means that once he is separated from his mother, he would remain at Sun Bear Forest, where he would need to rotate exhibit time with Marcella.

Rotating animals on exhibit is a common practice. It allows animals to have some time out in the larger open space of the public enclosure, where they get exercise and sunshine. It allows them time in the back, where they get some privacy and closer inspection by their keepers, important for observing changes in their health status or growth pattern. It keeps incompatible animals apart, important for non-social species or aggressive individuals.

Zoo-wide, there are a number of animals that share exhibit time with others via a rotation schedule. Our aged Manchurian brown bear, Blackie, recently began rotating with the younger grizzly bears to allow the youngsters more room to roam when on exhibit and ensure old Blackie gets plenty of peace and quiet behind the scenes (see Brown Bear Changes). Our giant pandas, solitary by nature, have long rotated through our two primary exhibits to allow the public to see all of our individual animals. Not since Hua Mei was dependent upon her mother have we had enough exhibits to house all of our pandas, so rotation has become a fact of life at the panda facility.

In Palu’s case, we have an even better option than rotation: delay weaning. In choosing this option for the time being, both bears get daily exercise during their time on exhibit. They also continue to enjoy each other’s companionship under this option. We are happy to note that, unlike Marcella’s first-born son Danum, Palu is not aggressive and demanding of his mother. The dynamic between them allows us to consider this option, whereas with other individuals it may not be possible to extend this relationship.

Further, at some zoo facilities in Europe, it is common practice not to wean young sun bears from their mothers, especially females, until they are of breeding age. In those cases, the young female is even introduced to a social relationship with her father, as the three bears are housed together when their personalities permit it. Thus, there is precedent for multiple generations of related bears being housed together in this species.

We need not be concerned that Palu will attempt to breed with his mother any time soon. We expect he will not reach sexual maturity for several more years. Long before then, we will have found a new home for him and weaning will take place. Or, a new male will have moved to San Diego to breed with Marcella, necessitating the removal of Palu from the social mix. Weaning will happen some day, but for now, mother and son will continue to remain a pair on exhibit. We hope you find them as interesting to watch as we do!

Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.


Zhen Zhen: Great Listener

Like her big sister Su Lin, Zhen Zhen is participating in the San Diego Zoo’s Giant Panda Hearing Study. Zhen Zhen is the youngest bear to be included in this research program and will provide us with new information regarding differences between the hearing sensitivity of young bears and that of adult bears. She has also been a remarkable example of how a young bear can learn a fairly complex task, and learn it fast!

Part of our study requires that the bear hold still, in a consistent location, until a tone is played. Nothing more is asked of the bear: just sit still and listen! Although this might not seem like it is much to ask, any of you out there with children will understand how challenging it is for a young and playful animal to just sit still, much less sit still AND listen. But Zhen Zhen, it turns out, is a great listener. Panda keepers and our research staff cannot help but smile as we watch Zhen Zhen during the hearing sessions, holding still with seemingly relaxed and steady concentration. She is getting it and is proving to be the best in her family at holding still and waiting for a tone.

A panda Zhen Zhen’s age in the wild would greatly benefit from being a good listener. No longer protected by her mother, and not yet full size or full of the wisdom that experience and maturity bring, she has to be on her toes, ready to avoid trouble and seek out good stands of bamboo.

We will continue to work with Zhen Zhen , Su Lin, Bai Yun, and Gao Gao over the course of this study. Not only are we getting great data on a poorly understood aspect of panda biology, but we are also having a chance to challenge our bears, and let them show us just how smart they are.

Megan Owen is a conservation program specialist for the San Diego Zoo’s Institute for Conservation Research. Read her previous post, Planes, Seismic Trains, and Snow Machines.


10 Reasons for Hope

The International Union for Conservation of Nature (IUCN) estimates that the current extinction rate for species on our planet is more than 1,000 times the rate it would be naturally, thanks to human factors. Climate change is implicated in reductions to water availability in ecosystems and ice in the Arctic. These days you only have to turn on the television to have a front row seat for the environmental disaster unfolding in the Gulf of Mexico. Everywhere you look, the news about the state of nature seems gloomy.

Working to make positive change in protecting rare species and their habitats is not an easy task. It takes the efforts of trained experts, working collaboratively, often on limited funds and against a ticking clock, to ensure the survival of a portion of our planet’s biodiversity. It requires the support of people and governments who believe in the value of such work. And it relies on the fundamental belief that such actions can make a difference. In short: it takes hope.

On May 21, Endangered Species Day, the San Diego Zoo’s Institute for Conservation Research will celebrate by launching its new initiative, “10 Reasons for Hope.” This effort draws attention to some of the successes we have had as a means by which to inspire us all to continue to fight the good fight. Our reasons for hope highlight projects making a difference in both wild and captive management of species at risk.

Several projects have contributed to increasing wild population numbers via reintroductions or translocations. The Institute has long been involved with the efforts to turn around the decline in California condor numbers; we have seen the wild population increase from 22 to 180 birds in recent years. In Hawaii, more than 200 puaiohi have been released into native forests. Close to home in Southern California, the numbers of endangered kangaroo rats have increased through translocations into good habitat. Without the work of our staff and partners, and the support of governments and communities, these species would have continued on their trajectory toward extinction. Now, we have witnessed the reversal of those trends.

There have also been significant achievements in managing captive populations. We have developed a screening lab for the chytrid fungus, which has devastated wild populations of amphibians the world over. By testing samples in captive populations, we can ensure their survival, and wild populations can be supplemented with animals from breeding programs. We helped launch Genome 10k, an effort to sequence the genomes of vertebrate species that will allow for better treatment of zoonotic diseases in both wild and captive animals. And the number of giant pandas in zoos and breeding centers worldwide should reach 300 this summer, ensuring a self-sustaining captive population.

Here’s something we can all be a part of: connecting our children to nature. There is an international movement to get kids out of the house and onto the trails, beaches, and parks in their area. Fostering this connection will ensure a future generation of environmental stewards, people who care enough to support conservation objectives. We can all participate by introducing our children, or other young relatives or friends, to the wilds in your own backyard.

The news of the world can be depressing, and the constant barrage of pleas for assistance or action on behalf of the world’s declining species and habitats can feel overwhelming. But take heart. In some places, and in big and small ways, efforts are making a difference. Our reasons for hope offer clear examples of how the battle can be won and how it is being won in many different ways. We invite you to allow a little hope to seep into the gloom and doom by visiting the 10 Reasons for Hope page. The future of biodiversity on the planet depends upon those who allow that spirit to guide them to action on behalf of us all.

Suzanne Hall is a senior research technician for the San Diego Zoo’s Institute for Conservation Research.