The Frozen Zoo stores cells from over 8,000 individuals in these metallic containers. Each individual’s cells are stored at the Wild Animal Park and at the San Diego Zoo for precautionary purposes.

These small black lines are chromosomes, each holding the genetic make-up of an orangutan. There are 46 total. Can you find them all?!

Heidi Davis explains the many uses of PCR, or Polymerase Chain Reaction, like determining the daddy of a particular offspring.

This refrigerator no longer holds food (unless you’re a vampire) but DNA samples.

Lastly, Heidi Davis shows us how to perform gel electrophoresis. Each intern had the opportunity to try out this cool technology!

Dylan, Photography Team

Preparing DNA for gel electrophoresis

An important part of the Genetics Division is the Frozen Zoo. It contains cell cultures from 8,700 different animals! It is used for karyotype documentation, sequencing of genomes, cloning, and learning about infectious diseases. It has also contributed to a greater understanding of the number of chromosomes in various animals. Knowing the number of chromosomes is important because it helps one tell the difference between species that may look very similar, it helps determine chromosomal abnormalities, and it helps with sex identification. 

We had the opportunity to experience first hand how useful the Frozen Zoo can be. We met Marlys Houck, a cytogenetics overseer, and Suellen Charter, a research coordinator. They are in charge of collecting samples for the Frozen Zoo as well as karyotyping every animal they get a sample from. Whenever an animal dies or receives surgery, a sample of fibroblast cells is taken from below the epidermis. The samples are put in a flask with growth media and eventually put into an incubator to grow. They are then divided into eight vials (four at the Zoo, four at the Wild Animal Park), and frozen at -196 degrees Celsius! A recent project involved samples sent from orangutans at Busch Gardens. We used amazing computer software to count the exact number of chromosomes from a cell and determined whether that animal was a Bornean or Sumatran orangutan.

Next we met with Heidi Davis, a research coordinator who specializes in molecular genetics. She uses DNA markers to compare different species, as well as different individuals within a species. She extracts DNA and uses gel electrophoresis to make sure it isn’t degraded. Then she uses PCR to amplify one part of the DNA and distinguish the minute differences between different DNA strands. With the orangutans from Busch Gardens, she performed a paternity test to see if the male was truly the father of the younger orangutan. Ms. Davis uses a variety of high tech machines every day to perform paternity tests as well as species identification. Today, we had the opportunity to get a taste of laboratory life by loading DNA into wells in a gel for later gel electrophoresis. It was tricky, but very interesting. Although it was quite a whirlwind of different experiences, I gained valuable knowledge that I have a feeling will be very useful to me in the future!

Natalie, Careers Team

One of the young condors flying in the enclosure.

The Zoo has thousands of birds in its collection, and not all of them are endangered. In fact, many of them are not even threatened. But that is not to say that the stable species will not be threatened sometime in the future. There is no way of knowing if the wild populations of an African bird may someday disappear, so the Zoo maintains happy, healthy populations as an insurance policy. The keepers who care for the birds do visual check-ups every day to make sure the animals are doing well and that there are no signs of illness.

Though the Zoo treats all animals with respect and care, there are some highly threatened species that get some extra-special care. The California condor went extinct in the wild in the mid- 1980s when the last 22 wild birds were rounded up and taken to facilities to be protected. The San Diego Zoo and other zoos have made specific efforts to help this critically endangered species. The condor’s numbers have bounced back from 22 to 350, which is an amazing leap; some of these birds are even flying free in their native range. Through genetic analysis, research, and a lot of patience, hundreds of chicks have been hatched from the handful that zoos were given. There are now several release sites where the condors are released after they have been raised by puppets that mimic their condor mothers.

The release sites are safer now than ever before because the lead bullets and buckshot used by hunters that posed a threat to the condors are now illegal in their range. In order to protect the condors from new threats they are not accustomed to, the birds are rehabilitated before they are released in what is called a “soft release.” This technique involves starting young birds in an enclosure at the site where they are to be released with an older bird that teaches them good habits and behaviors. This has been very successful because the released birds can learn the tools that they need before they have to be fully independent.

The proof that conservation works is now visible for many to see: there are now condors flying free in California, Arizona, and Baja California, Mexico. The conservation efforts brought them back from the brink and they now stand a chance to recover to their former glory.

Elise, Conservation Team

This puffed up, ruffled movement displayed by the Bateleur eagle at the Zoo is often displayed when the male feels threatened by invasion of territory or during the breeding season.

One of the adaptations of the Madagascan partridge is camouflage. The color of its feathers blends with the ground in its natural habitat. Bird keeper Michael Grue says, “They often look like potatoes when they huddle together for protection, and the only way to find the birds is by the glare of an eye.”

The tweezer-like beak and the flat feet of the white-headed lapwing help the bird survive in its indigenous habitat of tropical Africa, which has many insect-filled logs and muddy terrain.

The secretary bird, native to sub-Sahara Africa, has evolved over time to adapt to its grasslands habitat by developing legs that can grow up to three feet in height!

Although the California condor has one of the largest wingspans (about nine feet), its weight impairs it from a quick take-off and flying for a long period of time unless there is a strong current of wind.

Camille, Photo team

White-headed buffalo weaver

If you have pets, you know that animals often add an element of unpredictability to life.  Maybe your pups simply can’t grasp the concept of sharing their favorite toy. Maybe your cat doesn’t want to swallow its pill, or your bird just chewed up something important. Keeping a healthy, happy home for an animal can definitely be a challenge.

Bird keeper Michael Grue knows better than most how difficult it can be to maintain the health and happiness of an animal “home.” Each exhibit that is assigned to him is home to an animal family or two or three. A keeper’s day begins with a quick visit to each assigned exhibit to assess the general health of the animals inside. This requires a critical eye as birds will go out of their way to hide signs of weakness. Mr. Grue walked us through this observation process as we visited the Zoo’s pair of Bateleur eagles. 

Mr. Grue instructed us to take a good look at the birds and explained that there are a few key areas to keep an eye on, including vocalization and posture. An ill bird will often be quieter than usual and may sit stiffly or hunched over. As we approached the exhibit, the male eagle was calling to his mate. The pair then proceeded to “show-off” for us by spreading their wings and bowing to each other. These are all signs of good health and also indicate that the pair is progressing toward raising eaglets. If there had been any signs of a problem, Mr. Grue would make a note of it and, if needed, contact the Zoo’s veterinarians.

Feeding comes next on Mr. Grue’s daily schedule. Most of the birds are fed once daily, but the birds that have live crickets or mealworms in their diet are fed more frequently. As Mr. Grue said, “Fruit pretty much stays put in a feeding dish. Crickets just jump out.” This may seem inconvenient for the keepers, but it works out well for birds like the Rueppel’s white-crowned shrike.  Keepers toss the bugs into the air and the shrikes snatch them out of the air. It’s a win-win situation: the food doesn’t wander off and the exercise simulates natural behavior for the birds. 

Things get even more complicated when there are multiple species in an exhibit. Sometimes birds that have gotten along for years will suddenly become mortal enemies for no apparent reason. One bird may need a diet that’s high in iron, while the same iron level may be dangerous to its cage mate. In one case, a western white-crowned robin-chat escaped from its enclosure. Keepers tried to lure the escapee into traps with food, but to everyone’s surprise, a bird inside the enclosure “snuck” food through the wire to his friend outside! The keepers had to temporarily limit the food supply inside the enclosure so that the robin-chat would come into their traps.

Creativity, flexibility, and the ability to be observant are all necessary qualities for a zookeeper. In addition, Mr. Grue has a bachelor’s degree in biology and strongly recommends at least that level of education for anyone interested in zookeeping. Any experience working with animals is also good to have. Being a zookeeper is hard work, but rewarding. At the end of the day, you know that you’ve done your best to keep your charges healthy and happy.

Amy, Careers team

Condors in Elephant Odyssey at the Zoo

As you visit the Zoo, you may notice the extensive collection of birds exhibited throughout. In fact, there are more birds at the Zoo than mammals or reptiles. From passerines to song birds and waterfowl to raptors, the Zoo has a variety of birds that are common and highly threatened. The Zoo is home to some of the most fearsome and aggressive birds, including the harpy eagle Harpia harpyja and one of the most well-known in the world of conservation –the California condor Gymnogyps californianus.

The California condor is the epitome of conservation; it is one of the most successful species recovery stories, partly due to the work of the Zoological Society of San Diego. In 1985, there were only 22 condors left in the wild. Because of the extreme risk of extinction for the species, drastic measures were taken, and all surviving birds were removed from the wild and placed in several captive facilities, including the San Diego Zoo’s Wild Animal Park. This meant that the species was now considered extinct in the wild by the IUCN. Opponents of this plan did not like this decision and protested that the birds should be left in the wild, despite the fact that they would most definitely go extinct.

After mmany breeding initiatives, the captive condors were bred successfully. The plan was to release the captive-born condors when they were older so that the species could repopulate in its natural habitat. In order to do so, it was important that the chicks did not learn to be comfortable around humans. Through the least amount of contact and interaction, as well as puppet-rearing, the plan succeeded. The puppet-rearing method, which is feeding chicks with adult condor head puppets, grew to be a great success, and it has helped with the reintroduction of many condors.

Although the species is still listed as critically endangered, there has been a large growth in the wild and captive population. There are now over 350 California condors alive, most of which are in the wild. Reintroductions are ongoing, and there are release sites in Arizona and Baja California, Mexico. A big step in the protection of this species was the Ridley-Tree Condor Preservation Act, which requires the use of non-lead ammunition in the range of the condor. Many plans and methods of release are tested and used, and many have been contributors to the success of reintroduction.

The conservation story of the native California condor inspires people to be more aware and careful about their actions, whether it is in hunting, waste disposal, or product use. The California condor plays an essential role in our ecosystem. As a scavenger, the condor keeps our habitats healthy. The survival of this magnificent bird is vital for the productivity of its habitats.

Jonah, Real World Team

At the genetics lab, I inspected Sumatran orangutan cells (to be prepared for the Frozen Zoo) under a microscope.

One of their core activities includes the maintenance of, and addition of samples to, the Frozen Zoo. The Frozen Zoo is a collection of deep-frozen cell cultures representing over 8,700 individuals from more than 800 animal species, many of which are endangered. The Frozen Zoo is a landmark step in conservation efforts worldwide because it provides specimens for research everywhere. By providing DNA of endangered and even some extinct animals, the Frozen Zoo helps researchers establish missing links in the ancestry of animals. It also aids with genome sequencing, or the mapping of all the genes in an animal’s DNA. In the future, the Frozen Zoo might even be used for cloning. 

In order to prepare a specimen for the Frozen Zoo, a sample is taken from an animal from any number of sources such as skin, eye, or trachea. It is then cut into very small pieces and cultured, allowing the cells to multiply prodigiously. The vial containing the sample is then placed into the freezers where it is kept deep-frozen by bursts of liquid nitrogen. 

The genetics lab at the San Diego Zoo’s Institute for Conservation Research also works with species diagnosis and sex identification. Species diagnosis works to define the parameters of a certain species. A species is usually defined as a group of organisms that resemble each other and can interbreed successfully. A scientist might not be aware of a shift in a population from successful to non-successful interbreeding unless he or she looks at the population on a chromosomal level. If two individual animals have a mismatched number of chromosomes, they likely will not be able to produce viable offspring. This can be related to a conservation scenario with the example of the Fiji iguanas. The iguanas living in different areas evolved to possess a different number of chromosomes, so the breeding population was not as large as it appeared. The geneticists’ work is crucial because it can monitor these changes and prevent the conservationists from being unpleasantly surprised if it happens. 

Sex identification is a very useful task to the conservation breeding programs at the Zoo. In some species, such as the California condor, males and females are visually indistinguishable. Their gender must be determined by whether they have a ZW (female) or a ZZ (male) chromosome in their DNA. With the genetic lab’s help, species breeders can make decisions on living arrangements and how to pair individuals to avoid the effects of inbreeding. Similarly helpful to breeding is the ability of the genetics team to determine the genetic diversity of an individual. Genetic diversity is especially important when attempting to breed an endangered species whose numbers have been reduced. It is important to pair genetically diverse individuals in order to form a robust second generation of individuals that will be able to adapt to their surroundings. 

Mackenzie, Conservation Team

One of the many things we got to see was the Frozen Zoo. As the name implies, it is a collection of several species kept in freezers. While this may sound cruel at first, the species do not include the entire animal. Researchers take samples from the animal’s skin at convenience, which means that they only take samples when the animal is already in the lab or hospital for something else. The genetic zoo offers samples of DNA, RNA, cells, and tissue for research and many projects.

We were also able to see the DNA lab, where many samples are processed every day. In the lab many people work first to separate DNA from the other parts of the cells, and then study the DNA for the purposes of breeding, pedigrees, and disease control. While at the lab, we were able to help create a gel mold of DNA. After researchers separate the DNA from the other parts of the cell, they put it into a gel block. The dye that is mixed into the DNA slowly moves down the block, which stretches the DNA into a neat line in the process. This makes the DNA perfect for viewing and for study.

Genetics plays a vital role in many aspects of our daily life. The grocery store uses genetics to enhance many of the foods it sells. Many of the fruits and vegetables we eat have been altered genetically to be more appealing to the consumers. While this does a good job in making tomatoes redder and apples sweeter, it is also a step taken for our health. Many products are altered to make them less susceptible to disease. This not only reduces the need for pesticides, which take a great toll on our environment, but it helps to grow, transport, and sell the products more safely and efficiently.

Genetics are also very important in the world of medicine. There have been many recent studies that show promise for those with genetic diseases. Genetic studies are often used to comfortably treat these diseases if not find a cure. A recent study might even make going to the dentist easier. Researchers have found a gene that they believe might be related to the production of enamel. This could help with cavity prevention and with the production of replacement teeth.

Recent breakthroughs in genetics and the Wild Animal Park’s genetics lab all play a huge role in the world today. Genetics helps to make life easier, whether it’s making your trip to your produce aisle more pleasant, combating a genetic disease, or keeping your teeth white.

Savannah,
Real World

We begin our topography mapping with this contour lining of the area.

Zoo Interns attempt to complete their topography map of an area behind Elephant Odyssey, which is a possible site for a quarantine pen.

Tod Chee, GIS specialist, explains to us the final steps of our topography graph

This is the finished topography map; the line of sight allows us to estimate what height the barrier should be.

Tod Chee shows us where our real line of sight would be, comparing the real thing with our topography maps

The area we surveyed for the potential quarentine pen.

We were able to see firsthand the attention to detail that the geographic information specialists dedicate to their work. Their measurements are accurate to within an inch when they translate their work from paper to the park. We saw some of the planning for a new quarantine facility at the Zoo, and the goal was to build a fence to keep the animals in and a barrier to keep guests from seeing the fence. There are several reasons why the specialists put so much detail into figuring out exactly how much the guest will see and how much is needed to block their view. For one, the Zoo wants precise measurements so they will not waste money on guessing how high a barrier needs to be. For another reason, they want to maintain the illusion that there is very little separating the guest from the animals that seem so close. The third reason is that GIS wants to maintain their intelligence on the Zoo and the Wild Animal Park, so they are continuously updating the already existing maps on everything from enclosures to facilities.

The attention to detail may not seem like it has much applicability to conservation, it creates some of the foundation for the Zoo as a conservation minded place. The fact that they want to know measurements down to the inches means that they do not want to spend frivolously on fences when accuracy can let them spend it on conserving the habitats of wildlife around the world. The aesthetic of the Zoo is maintained through GIS’s meticulousness as well. They are able to hide some of the boundaries from the guests and create more of an authentic feel that can work wonders for conservation. If the guest feels like they are close to an animal and they are experiencing the creature in its wild state, than they are much more likely to care about that animal. It is one thing to see a picture of an elephant or a giraffe but it is quite another to watch it as it goes through the exhibit searching for food. Making the guests feel engaged because they feel like nothing is separating them from the animal is one way that conservation is aided by GIS. The exact placement of every animal and bathroom is mapped by GIS and the information is updated and maintained constantly. This allows for easy access and astonishing accuracy so anyone can step in and clearly see where a quarantine pen would need to be placed so all of the animals will be safe. This will allow for smooth transitions in the future and will let the animals, and not logistics, be the focus.

The work of the Geographic Information Systems has far reaching affects on all aspects of the Zoo, and conservation is certainly one of them. Through the effort of a few specialists, the whole Zoo benefits from a wealth of information on the land beneath their feet.

Elise, Conservation Team