Reptiles and Amphibians

Reptiles and Amphibians

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The Python Challenge

Burmese pythons are an invasive species in Florida's Everglades.

Burmese pythons are an invasive species in Florida’s Everglades.

When a male reptile in the San Diego Zoo collection passes away, it is my job to freeze his sperm. Unfortunately, there has been so little research done on freezing reptile sperm that there are no guidelines in the scientific literature. So, we have to develop the protocols for ourselves, which requires a great deal of research and a lot of sperm samples. This scenario plays out all too often in the Reproductive Physiology Lab of the San Diego Zoo Institute for Conservation Research. We always need more samples! How could we know how to freeze golden lancehead sperm without any practice on this or any related snake species?

Our lab group has struggled with this problem for years and has come up with some creative solutions to the sperm shortage problem. My colleagues Nicole Ravida, Dr. Barbara Durrant, and I began scouring the Internet to find a way to collect large numbers of reptile sperm samples in a short period of time to use as models for endangered reptile species. That’s when we learned about the Python Challenge in the Everglades.

Carly and Barbara got an early start in the Everglades.

Carly and Barbara got an early start in the Everglades.

The Florida Fish and Wildlife Conservation Commission (FWC) launched the Python Challenge to raise awareness about Burmese pythons and how this invasive species is a threat to the Everglades ecosystem and its native wildlife. The Burmese python is one of the deadliest and most competitive predators in South Florida. With no known natural predators, population estimates for the python range from the thousands to hundreds of thousands. A severe decline in a variety of mammal populations in the Everglades over the last eight years coincides with the proliferation of the invasive Burmese python. Necropsies on the captured snakes reveal what pythons are eating, their reproductive status, and location data from the hunters that will help scientists figure out where the snakes are living—valuable data for researchers working to stop their spread.

The Python Challenge was a month-long harvest open to anyone, and we knew this would be our opportunity to collect many snake sperm samples. We immediately contacted the Invasive Species Program staff at the University of Florida, one of the Python Challenge partners, and the project all started to fall into place. Barbara and I arrived in Florida and immediately collected all the supplies and equipment we had sent ahead to Zoo Miami and then purchased thick sheets of dry ice. Lining a large Styrofoam box with the cold sheets, we fabricated a minus 112-degrees-Fahrenheit (-80 degrees Celsius) freezer for one of our freezing protocols. With everything we would need piled into our rental car, we finally made it to the hotel room and organized our temporary lab.

The Python Challenge check-in station was simple but effective.

The Python Challenge check-in station was simple but effective.

The next day we drove to the Python Challenge check station, which consisted of a pickup truck and a tent. Hunters came to the check station to have their snake(s) measured and documented by the Invasive Species Program staff. Prizes were awarded to the hunter who harvested the longest snake and the one who brought in the most snakes. We anxiously waited with the people from the University of Florida for a male snake to be brought in. Unfortunately, the first snake to arrive had been frozen the previous day. We needed fresh, cooled samples, not frozen, so we continued to wait for another snake, which came in a few hours later. We dissected out the vas deferens, where the sperm is stored, on the back of a pickup truck as the sun set over the Everglades. We immediately put the tissue in saline in a cooler and raced back to the hotel to process the sample. But it was a bust—no motile sperm. We just had to hope for better luck the next day.

The vas defrens were taken back to the makeshift lab in the hotel room for processing.

The vas defrens were taken back to the makeshift lab in the hotel room for processing.

The next morning we got a call from our colleagues at the University of Florida saying that they had two live snakes. This was fantastic news, because we would be able to obtain fresh sperm samples. During the snakes’ necropsies, we collected the vas deferens and drove an hour back to our hotel room to process the samples. Fortunately, both males had motile sperm. More sperm, in fact, than we had ever seen and certainly more than we could ship back to San Diego. After several hours of freezing the sperm in our homemade dry-ice box or in liquid nitrogen vapor, we received a call that another male snake was available. We drove back to the Check Station, arriving after dark. We removed the vas deferens in the back of the truck using my phone as our light source. We made it back to the hotel room for another five hours of processing and freezing, falling into bed at 1a.m. It was a very long day but a successful one, with sperm from three snakes safely stored in our shippers.

Our luck continued the next day, with an interesting twist. This time the live snakes had been brought to another checkpoint, and we would need to transport them to the University of Florida lab. It was a bit surreal to be driving down the highway with three large pythons in snake bags in the trunk. We wondered if we had violated the rental agreement when we promised not to carry pets in the car. It was worth the risk; snakes and humans arrived safely at the university, and we froze three more sperm samples back in our hotel room lab.

Overall, it was a successful trip to the Python Challenge in the Everglades. We froze 130 vials of sperm, shipping them back to San Diego. Then began the long process of thawing and evaluating each sample, comparing three different freezing protocols to determine which one resulted in the best post-thaw viability. We have analyzed the data, and we have an early winner among the protocols we tested. However, we will need to repeat the experiment with improved protocols to maximize sperm motility and membrane integrity, both of which are essential for potential fertility.

Although we will never use the sperm of this invasive species for artificial insemination (we certainly don’t want more Burmese pythons in the United States!), we have taken a big step forward in the development of sperm-freezing methods for its endangered relatives such as the Indian python and the Cropan’s boa.

Carly Young is a senior research technician for the San Diego Zoo Institute for Conservation Research.

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The International Language of Crocodiles

The Abidjan Zoo's director poses with a large male alligator at the St. Augustine Alligator Farm.

The director of the Ivory Coast’s Abidjan Zoo poses with a large male alligator at the St. Augustine Alligator Farm.

At the San Diego Zoo, employees have the opportunity to attend professional development courses to expand our knowledge base and to make the Zoo a stronger organization. For the past three years, the Zoo’s Reptile Department has sent an employee to the St. Augustine Alligator Farm in Florida to attend a 10-day Association of Zoos and Aquarium course called Crocodilian Biology and Captive Management. The San Diego Zoo has one of the most diverse collections of crocodilians in the United States, making this course very beneficial to a reptile keeper, as s/he is exposed to many different species of crocodilians. When the collection expands, as more crocodilians arrive at the Zoo, we will be ready to properly care for these beautiful animals.

Over the past several years, the Reptile Department has sponsored the work of Dr. Matt Shirley, a Ph.D. student from the University of Florida, Gainesville, in West Africa. Dr. Shirley discovered a new species of crocodile, the West African slender-snouted crocodile, which he later determined is on the verge of extinction. For over 150 years, this species was thought to be the same species throughout its range in central and western Africa. His research has separated the slender-snouted crocodile into the western and central slender-snouted species. His research and study of the region led him to the only zoo in the Ivory Coast, the Abidjan Zoo, where a substantial number of adult West African slender-snouts are housed.

Jeremy, left, and Digbe maintain a strong bond when it comes to crocodilians!

Jeremy, left, and Digbe maintain a strong bond when it comes to crocodilians!

The staff at the Abidjan Zoo have not been trained on the proper care, husbandry, diet, and safe handling of these crocodiles. This can be dangerous to the crocodiles and to the lives of the staff. With this notion in place, and Matt Shirley’s ties with the St. Augustine Zoo, the director of the Abidjan Zoo received a grant to attend the Crocodilian Biology course in Florida. The director of the Abidjan Zoo, whom I would later come to know as Digbe, had never left the Ivory Coast. As a former colony of France, the official language of the Ivory Coast is French. Digbe knew very little English. As a fluent French-speaking reptile keeper, the San Diego Zoo saw a great opportunity for me to travel to the St. Augustine Zoo and help translate for Digbe. This was a once-in-a-lifetime opportunity to learn from some of the country’s premier crocodilian experts, and this course offered the best chance to help the director of the Abidjan Zoo gain a better understanding of crocodiles and thus share it with his staff.

My love of reptiles helped me translate all the amazing and beneficial information I was learning in class to Digbe. During the ten days, Digbe and I learned a lot about each other, and, thanks to the San Diego Zoo, we both left the Crocodilian Captive Management course with a better understanding of how to properly care for our beloved animals.

When speaking with Digbe, I learned that our zoo is blessed to have a plethora of books and resources to help make our collection one of the best in the world. The Abidjan Zoo is not as fortunate when it comes to resources. To help him out, I have sent over educational packages to help inform the children that visit the zoo (over a million!) on the importance of all animals, native and foreign. To this day, Digbe and I still communicate through email, sending pictures and updates of the new species of crocodilians.

This year, our Reptile Department and the American Association of Zoo Keepers organized its second annual “Croctoberfest.” All of this year’s proceeds with help benefit the slender-snouted crocodiles and future projects the San Diego Zoo has with the Abidjan Zoo. This May, the second annual Golf for Wildlife event will raise funds to send needed education supplies to the Abidjan Zoo’s newly built education center.

Hopefully, one day I will be able to visit Digbe in the Ivory Coast and help the fight to end extinction of these beautiful crocodiles!

Jeremy Fontaine is a keeper at the San Diego Zoo. Read his previous post, Alligator Training.

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9 Culturally Haunting Animals

Since Halloween is around the corner, it’s time to learn about some creepy critters that have been haunting cultures around the globe. It’s also time to separate fact from fiction, the latter being partially responsible for some bad reputations surrounding some incredibly innocent creatures. It’s important to note that just because certain species are portrayed as terrifying monsters in the media or fancy folklore doesn’t mean that said animals are, in fact, flesh-eating freaks of nature. In other words, the expression “don’t believe everything you hear” exists for a reason.

So without further ado, keep reading for some animal-inspired myth busting.

Satanic leaf-tailed gecko

One look at the satanic leaf-tailed gecko and you’ll understand why this demonic reptile made the list. This master of disguise has a body that mimics a dead leaf, which protects the gecko in its native Madagascar. To trick predators, the satanic leaf-tailed gecko can also flatten its body like a pancake and deliberately shed its tail. Despite how scary this tiny reptile appears to be, it’s irrational to denounce the species for its kooky characteristics.

Aye-aye

The Safari Park’s Lemur Walk demonstrates how curiously cute these prosimians can be. Yet the Malagasy people of Madagascar believe that lemurs embody the souls of their ancestors. In fact, the word lemur stems from the Latin word lemures, which translates to “ghosts” or “nocturnal spirits.” In Roman mythology lemures weren’t just spirits—they represented lethal, vengeful spirits, the kind nightmares are made of. This misunderstanding has threatened the lives of one subspecies in particular, the aye-aye, which is often killed on sight because it’s perceived as a bad omen. The only bad omen here is the fact that lemurs status was recently moved from vulnerable to endangered on the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species this year.

Tasmanian devil

The Tasmanian devil got its moniker for its dark color and fierce temper. These nocturnal marsupials let out spine-chilling screams while feeding together at a carcass. When they feel threatened or excited, their little ears change to bright red. While their name appears to suit their style, what’s even scarier is the fact that Tasmanian devils are critically endangered. In other words, Loony Tunes’ exaggerated portrayal of Taz as a voracious lunatic may have done more harm than good. Currently, the San Diego Zoo is one of just two facilities in North America to house these little devils.

Snow leopard

As elusive as they are stunning, snow leopards have been creatures of Nepalese myths and Buddhist culture for centuries. Luckily for them, their reputations tend to be more positive than the aforementioned animals. Their shy and mystifying ability to almost disappear in their native habitat has established snow leopards as shape-changing mountain spirits to the local people of Central Asia, who know them as “ghost cats.”

Jaguar

Another mysterious big cat that’s earned a prominent place in local legends is the jaguar. These cool cats are depicted in ruins throughout Central and South America, but instead of symbolizing a spooky species, jaguars represent beauty, strength, and unparalleled intelligence in the New World. In fact, some tales suggest that jaguars move between worlds because they’ve adapted to life in the trees as well as on the ground. Their ability to hunt during the day and night is equally impressive.

Vultures

Most vultures depicted in cartoons, comics, or films reinforce that one-dimensional image we all have: a symbol of impending doom or death. Even though the entertainment industry has deemed this winged species as wickedly horrid, once you get past their harsh appearance, you’ll learn that some cultures actually idolize vultures. Aside from ancient mythology and rituals, vultures are crucial to habitats, as they remove dead carcasses without spreading disease. So instead of fearing vultures, we should thank them for taking care of at least one dirty job.

Crow

Another bird that’s been doomed by ancient legends and modern Hollywood is the crow. Despite the fact that the comic book series and subsequent action movie was based on a brutal story of murder and vengeance, Edgar Allan Poe’s preceding works in the mid-1800s further expanded the crow’s negative connotations. Perhaps its slick, dark plumage is to be blamed for the crow’s lack of love, but in nearly every culture’s mythological past– from Ireland to Islam–this species was associated with war, death, murder, and other terrifying nouns that keep us awake at night.

Gila monster

With a name like Gila monster, it’s no surprise that this species has one of the worst reputations in the reptile world. Native to northern Mexico and our southwestern states, this lizard is feared by humans for a bevy of false reasons. For starters, some people think the Gila monster can spit deadly venom, sting with its tongue, and even kill people with its poisonous breath. While the Gila monster is, in fact, venomous, a bite from one of these scaly creatures rarely causes death…in humans. Nothing to fear here.

Komodo dragon

The Komodo dragon is another victim of bad publicity. While it wins the prize for largest-living lizard in the world, people have feared the dragon because it’s believed that its saliva contains a deadly bacteria. The jury is still out on this one, so stay tuned for another blog that addresses this topic.

Join the Halloween fun! Share your spooky species or animal legends in the comments below.

 

Jenn Beening is the social media specialist for San Diego Zoo Global. Read her previous post, 7 Animals You Didn’t Learn In School.

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Drought: Reptiles Don’t Like It, Either!

A cell phone photo taken of the habitat at the Safari Park Reserve in August 2014 shows just how devastating the drought has been on our local habitats.

A cell phone photo taken of the habitat at the Safari Park Reserve in August 2014 shows just how devastating the drought has been on our local habitats.

The drought has been awful for Southern California residents: dry, hot days, water restrictions, and a brown landscape. These are things we can all live with, but for our resident native reptiles and amphibians, drought can be a life-or-death situation. I have been working in the San Diego Zoo Safari Park’s Biodiversity Reserve (a 900-acre area adjacent to the Safari Park) for 15 years studying the reptile and amphibian species that call it home. This year I began a project studying a relatively rare coastal sage scrub species, the coastal patch-nosed snake Salvadora hexalepis virgultea. My plan was to capture at least 10 animals and implant them with radio transmitters so I could follow their movements and study their ecology. On normal rainfall years I see an average of eight of these wonderful snakes, so I figured that if I actively searched for them, I would be able to get a good sample size to study. However, I did not count on the drought being so intense.

Snakes get most of their water from the food they eat, and when there is no water, the food disappears as well. Many of our small, native animals tend to stay underground during such “tough times” and await better weather. Not only did many of the prey species disappear over the spring and summer, but the snakes also stayed deep underground to conserve moisture. Some snakes and other reptiles came to the surface for a brief period during the breeding season (April through June), and I was able to find a couple of patch-nosed snakes for my study. Unfortunately, reptile activity ceased altogether soon after. On a good spring day in a year with normal rainfall, I can find up to 20 snakes belonging to 8 to 10 different species in a single day. This year, in stark contrast to normal expectations, my best snake day yielded just two snakes. In addition, I spent nearly every day in the field for seven weeks in May and June and only saw two rattlesnakes. As the summer progressed and the habitat became more and more dry, very little lizard and snake activity was observed.

A red diamond rattlesnake found during a cover board array survey in 2010 at the Safari Park Biodiversity Reserve shows how lush and green the hills were that year.

A red diamond rattlesnake found during a cover board array survey in 2010 at the Safari Park Biodiversity Reserve shows how lush and green the hills were that year.

August is often our driest month, so we rarely see many animals in the field at that time. We often wait until late September before we start seeing hatchlings and juveniles along with occasional adult animals. This year, the young snakes have been virtually nonexistent, and that makes sense. If the adult female snakes and lizards cannot gain enough body mass, they generally will not reproduce. Since most of our wild animals stayed underground for much of the year, they probably did not feed and therefore were unsuccessful in breeding.

Last week I saw firsthand how difficult the drought has been on our native snakes. While walking through the coastal sage, I found a large, female red diamond rattlesnake Crotalus ruber. She was very thin and could barely move. I presume she had recently given birth (rattlesnakes in San Diego County give birth to live young in August and September) and just did not have enough body mass to make it through her pregnancy. No baby snakes were found in the vicinity, and I can only hope this female pulls through. If she had babies, they will, hopefully, be able to hold out until the rains eventually arrive.

A cell phone photo shows an emaciated red-diamond rattlesnake at the Reserve in September, 2014. Many of our local reptiles and amphibians are suffering from the recent drought.

A cell phone photo shows an emaciated red-diamond rattlesnake at the Reserve in September, 2014. Many of our local reptiles and amphibians are suffering from the recent drought.

In over 30 years of field “herping” (searching for reptiles and amphibians), I have not experienced drought conditions worse than those seen in 2013 and 2014. In fact, the North American Field Herping Association has shown just how bad the drought has been on Southern California snakes. When comparing non-drought year data from July 1, 2010, to June 30, 2012, with drought year data from July 1, 2012, to June 30, 2014, for snakes found in Los Angeles, San Diego, Orange, San Bernardino and Riverside counties, 4,971 snakes (1,055 hatchlings) were found between 2010 and 2012 whereas only 2,888 snakes (680 hatchlings) were found from 2012 to 2014. It is also interesting to note that there were more contributors to the database in the latter years, so roughly half the snakes were found by considerably more field herpers in the drought years than in the normal rainfall years, and roughly half the hatchling snakes were found in the drought years than in the normal years.

Here's a portrait of a healthy long-nosed snake in the Safari Park Biodiversity Reserve in 2009.

Here’s a portrait of a healthy long-nosed snake in the Safari Park Biodiversity Reserve in 2009.

So what does this all mean? Nobody can be certain right now. We do know that our climate has boom and bust years and drought and rainfall totals are very cyclical for most areas of the world. However, our findings to date do suggest that climate change is occurring at a rapid pace, and we all need to do our part to protect the environment and our natural resources, especially the snakes!

Jeff Lemm is a senior research coordinator in the Behavioral Ecology Division of the San Diego Zoo Institute for Conservation Research.

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Catching Rock Iguanas: Easier Said than Done!

Corinne PisacaneThis year I traveled to the Turks and Caicos Islands to study wild rock iguanas. The Turks and Caicos rock iguana Cyclura carinata is endemic to this Caribbean country and is critically endangered. Our team flew to the island of Providenciales, the main hub for tourist travel. From there we continued in a much smaller plane across the beautiful and shallow waters of the Caicos Bank to our final destination, Big Ambergris Cay. This island, located about 40 miles east of Providenciales, is diminutive in size, measuring about 4 miles (6 kilometers) long and only 1 mile (1.6 kilometers) wide. Its highest point is less than 100 feet (30 meters) above sea level. In addition to the iguanas, this secluded island hosts a number of private residences, and there are plans for a large housing development, which poses a potential threat to iguana habitat on the island.

During my time on Big Ambergris Cay, I was involved with a graduate student’s dissertation project involving iguana capture, relocation, and the subsequent examination of homing abilities (among a number of other iguana-related activities!). Every day we set out after it warmed up enough for iguanas to come out of their nooks and holes. Once we located individuals of interest, we set about stalking them. A number of our team members then attempted to catch iguanas of interest with varying degrees of success. Sometimes the lizards were just too fast and would elude our attempts with ease!

Once caught, our next challenge was to try to take a blood sample from each iguana to measure baseline stress hormones. From the moment we caught each iguana, we had exactly three minutes to successfully collect the blood. Any time over three minutes meant that stress hormones (or glucocorticoids) had already reached the iguana’s circulation, meaning we were measuring its stress response to the capture, which was not our goal. As you can imagine, this made for a very exciting three minutes!

If we were not successful, the iguana would be released and not considered as part of the study. If we did succeed, the iguana was then numbered using a system of color-coded beads strung through Spectra line and placed on both sides of the iguana’s dorsal crest between the shoulder blades. This dorsal skin is similar to that of our earlobes, and the stringing of the beads is thought to feel much like piercing one’s ears. Once we were finished marking individuals with beads, each iguana was also fitted with a small radio transmitter to enable future tracking of their movements on the island.

After the identification beads and radio transmitter were secured, iguanas were released at their point of capture and tracked for two weeks to determine their home range. Then they were recaptured and relocated to a different study site just under a mile away to determine if relocation might be used to successfully mitigate future development. As soon as they were released, the race was on! Equipped with radio-receiver equipment, researchers tracked the movements of the iguanas daily to investigate where they went. It appears that adult iguanas can usually find their way home, although how they do so is still not fully understood. By contrast, the homing skills of juvenile iguanas don’t appear to be as developed, and they usually stay put in their new home. For this reason, juvenile iguanas make better candidates for relocation than adults.

Alongside all the capturing and relocating of iguanas, our team also processed all the blood samples collected. This was no small task, as the logistics of processing blood on a small Caribbean island are very involved and time sensitive. Samples had to be frozen immediately, which required transferring them from a portable mobile cooler, carried by each researcher, to a larger cooler on a golf cart (the only mode of transportation around the island!) and then, finally, back to one of our rooms where we’d set up a mobile laboratory. Overall, this was quite an operation! Picture at least half of a dorm room set up as a temporary lab with collection tubes, a centrifuge, slide-staining equipment, and blood-draw needles.

Having traveled to a number of tropical places, I had expected the Turks and Caicos landscape to be all soft sand and friendly flora, with iguanas living in a beach environment. How wrong I was! All this capturing, relocating, and tracking takes place on volcanic-like ground that can quickly tear up ordinary shoes. The ground is also uneven and makes capture and tracking a slow and strenuous process. In addition, the small shrubs and trees are full of thorns and are quite abrasive. As a result, we always wore long pants and covered up at all times, making the work more challenging as it got extremely hot outside. Thick-soled shoes were also critical if we were to move around quickly enough to capture iguanas and avoid large thorns entering the soles of our feet. While we find it difficult to deal with this kind of environment, the iguanas have evolved to be perfectly suited to it.

This type of research is critical to gain a thorough understanding of the biology and behavior of the Turks and Caicos rock iguana. As with most endangered species, we need to be diligent about setting aside the necessary habitat for these amazing reptiles. Rock iguanas throughout the Caribbean are in danger of losing their habitat as a result of human-related pressures. I learned a great deal while on Big Ambergris Cay and am very grateful that I could be involved with iguana conservation in such an amazing habitat!

Corinne Pisacane is a senior research technician for the San Diego Zoo Institute for Conservation Research. Read her previous post, ISWE: Cheetah Pseudopregnancy?

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The World for a Desert Tortoise

Tortoise Montana shared some attitude with Paul.

Tortoise Montana shared some attitude with Paul.

While working at San Diego Zoo Global’s Desert Tortoise Conservation Center in Las Vegas, I have handled over a thousand desert tortoises. All of them are important to me. One function of my job is to find tortoises and bring them in for medical check-ups, evaluations, and preparation for relocation into the wild. Most desert tortoises are calm, curious, and easy to handle if you are nonthreatening. One tortoise, however, stands out among them all.

Early April. I had to go into Pen #362, find tortoise #17894, and bring her in for medical check-up. The tortoise was in an artificial burrow. I got on the ground, flipped on my flashlight, and prepared for the rough work of trying to coerce a well-dug-in tortoise to come out. Suddenly, one fierce reptile charged out! She scampered all the way from the back of the burrow, legs swimming through dirt and pebbles. She ran at me as if she wanted to fight! All I could think of was Al Pacino, as Tony Montana in the movie Scarface, confronting me. She seemed to be saying “You want to mess with me!? O-kay! You think you’re tough!? O-kay!” I picked up the tortoise, her legs flailing while trying to get at me. From now on, #17984 is Tortoise Montana!

She's now more relaxed around him.

She’s now more relaxed around him.

After her check-up, she was placed back into pen #362. I fed her in the mornings, and over time she became more agreeable to my presence. By June, my route had changed and others fed Tortoise Montana, but I would occasionally go visit her whenever I could. Instead of charging out, she would calmly walk out of the burrow to come near me. Sometimes, if I had extra food, I would make a special trip to her pen to let her have it. One morning, I watched her drink from a puddle of water created by the irrigation drip system. During the heat of summer she usually slept in the back of her burrow. I asked a colleague about her status. She was healthy and would soon be translocated to the desert!

September: Translocation Week. Many tortoises were brought into the lab for their preparation. My job is to put translocation ID tags on the tortoises’ shell. I scanned the lab. There she was! A plastic box tote labeled 17894 362! I opened the tote. While sitting on her bed of hay, she was relaxed and stayed still as I applied the tag.

Paul attaches a translocation ID tag on a desert tortoise.

Paul attaches a translocation ID tag on a desert tortoise.

The next day I traveled with my colleagues out to Eldorado Valley. I knew Tortoise Montana was in the last pickup truck of our convoy. After we arrived at the release site, while gathering the tortoises, I found her tote and placed her at the front of the line for fluids. Afterward, I picked up her tote and walked into the desert with her. I eventually found a shady spot that had lots of desert flora and grass. I lifted Tortoise Montana, looked into her eyes, and gently placed her on shady ground. I filled out her data sheet, made my observations, and said “good-bye” as she looked around at her new home.

Whenever I walk by pen #362 I feel a little sad. The pen is empty now. But I feel good, too, because I know Tortoise Montana has what I know she needs: “The world…and everything in it.”

Paul Griese is a research assistant at the San Diego Zoo’s Desert Tortoise Conservation Center. Read his previous post, Burrowing Owl: Who Are You?

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Rare Frogs Holding Their Own Despite Drought Conditions

mountain yellow-legged frogA recent survey of mountain yellow-legged frogs released into the wild by San Diego Zoo Global wildlife conservationists indicates that the populations are showing signs of stress related to drought conditions in California. The juvenile frogs, released into the San Jacinto mountains in two protected sites, are representatives of a species brought to the brink of extinction by the threat of wildfire, habitat destruction and chytrid fungus. The young frogs hatched at the San Diego Zoo Institute for Conservation Research and were introduced as tadpoles into the wild in 2013.

“When we released these frogs into the wild, we knew they would be facing natural challenges to their survival, like predation,” said Frank Santana, a research coordinator with the Institute for Conservation Research. “The drought is adding an additional challenge to their survival, but we are still finding a significant number of frogs that are healthy and growing.”

Of the 300 tadpoles that were released, researchers believe about 25% continue to survive. The species is believed to number less than 200 individuals in the San Gabriel, San Bernardino and San Jacinto mountains, where they once thrived. Institute for Conservation Research conservationists, working in collaboration with government partners – U.S. Geological Survey, U.S. Forest Service, U.S. Fish and Wildlife Service, California Department of Fish and Game and University of California – are working to repopulate Southern California with these rare frogs.

CONTACT: SAN DIEGO ZOO GLOBAL PUBLIC RELATIONS, 619-685-3291

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New Generation of Rare Turtles Released into San Diego Reserve

Pond turtle releaseFive juvenile western pond turtles were released into the Sycuan Peak Ecological Reserve today by a team of federal, state and zoo scientists. The released turtles are part of the “headstart” program, which involves raising hatchlings at the San Diego Zoo to a large enough size and then releasing them into the wild, giving them a better chance of surviving and fending off natural predators.

The western pond turtles are California’s only native freshwater turtle species, a species that was once widespread in California, Oregon and Washington. They are now uncommon, especially in southern California, due to habitat loss and invasive, nonnative predators like bullfrogs and largemouth bass, which eat up the tiny hatchling turtles that are no larger than a quarter.

“Along with USGS we’re able to monitor these turtles with their radio transmitters and check on them periodically to see how they’re doing,” said Tommy Owens, senior keeper with the San Diego Zoo’s Department of Herpetology. “It’s really important here at the beginning of the release, because the turtles might not stay put and we want to be able to find them easily. Through radio tracking we can see the use of habitat, their behaviors and check on their overall well being.”

The five turtles released this morning were each fitted with a miniature radio transmitter prior to the release. Researchers attached these tiny antennae to the juvenile turtles’ shells so they can regularly check on the turtles’ growth, physical health and behavior. The transmitters were applied with a silicone sealant that allows the young turtle’s shells to grow and expand, even with the transmitter device attached to it.

Since the first generation of “headstart” turtles was released over a year ago, researchers monitoring the program have noticed progress and have been able to catch those turtles periodically to gather their measurements. After examining the turtles and checking their transmitters, researchers release them back into the same watershed.

The Sycuan Peak effort is a joint project of the U.S. Geological Survey (USGS), San Diego Zoo Global, the California Department of Fish and Wildlife (CDFW) and the San Diego Association of Governments (SANDAG). The project is testing conservation strategies to help western pond turtles and other native species, since many California ecosystems are being impacted by invasive, nonnative species accidentally or intentionally introduced by humans. The SANDAG TransNet Environmental Mitigation Program (EMP) funded the USGS’ initial work to support the restoration of the western pond turtle.

Photo taken on July 31, 2014, by Ken Bohn, San Diego Zoo.

CONTACT: SAN DIEGO ZOO GLOBAL PUBLIC RELATIONS, 619-685-3291

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Rare Night Lizards Form Satellite Population at San Diego Zoo

island night lizardA recently recovered endangered species, the island night lizard, has been added to the list of reptile species at the San Diego Zoo. Five night lizards arrived at the Zoo on July 25, 2014, brought by the U.S. Navy to be available for guest viewing. The species was removed from the endangered species list by the U.S. Fish and Wildlife Service on May 1, 2014.

“It is one of the few species that visitors to the Zoo will see that was recovered under the Endangered Species Act, and the only one estimated to occur in the millions on U.S. Navy Lands,” said Dr. Robert Lovich, senior natural resource specialist at Naval Facilities Engineering Command (NAVFAC) SW, Desert Integrated Product Team.

The island night lizard Xantusia riversiana is native to three federally owned Channel Islands (San Clemente, San Nicolas, and Santa Barbara) located off the Southern California coast, and a small islet (Sutil Island) located just southwest of Santa Barbara Island. San Clemente and San Nicolas islands, used by the U.S. Navy as training lands, are also home to several unique and endangered species that the naval command works to preserve.

“San Clemente Island is critical to the Navy’s ability to train and prepare sailors to fight in realistic situations. By adaptively managing wildlife like the island night lizard, we can conduct our mission requirements and remain great stewards of our natural resources. We’re pleased the San Diego Zoo has an opportunity to share this interesting creature with the public,” said Capt. Christopher E. Sund, commanding officer of Naval Base Coronado.

The island night lizard was placed on the endangered species list in 1977 because its habitat was threatened by feral goats, pigs and predators that had been introduced to the island. In 1992, the Navy removed the last of the feral goats and pigs from San Clemente Island and has an ongoing program to trap and remove feral cats and rats. In conjunction with these efforts, nonnative species of plants were removed from the island as well, greatly improving the habitat of the night lizards and promoting their recovery.

“Now that the species is recovered, it is important to ensure its ongoing survival by creating a satellite population away from its island home,” said Kim Lovich, curator of reptiles for the San Diego Zoo. “This satellite population provides insurance that the species will survive even in the event of a sudden natural disaster to its island home.”

The lizards will soon be available for viewing at the Zoo’s reptile house.

Photo taken on July 25, 2014, by Tammy Spratt, San Diego Zoo Global.

CONTACT: SAN DIEGO ZOO PUBLIC RELATIONS, 619-685-3291

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Volunteers Help Desert Tortoises

Volunteer Kimi Sharma won a contest for most volunteer hours worked in June: 71 hours!

Volunteer Kimi Sharma checks on a resident of the Desert Tortoise Conservation Center.

I’m always amazed to see volunteers bouncing into the Desert Tortoise Conservation Center at 5 a.m. to start the day. Most of our volunteers drive long distances to give of their time and help the tortoises. We had wonderful volunteers this season, all very dedicated! They have already put in over 600 hours so far this season!

Our volunteer coordinator, Lori Scott, did a great job coordinating, orientating, and keeping up with the various schedules of the volunteers. Lori’s job was to also make sure they felt appreciated and were gaining a valuable experience. Kimi Sharma won a contest for most volunteer hours worked in June: 71 hours! Before Kimi left to head back to school in Boston, she had acquired 155.5 hours of volunteer work. Kimi was kind enough to bring all of us lunch on her last day, which we appreciated very much…I don’t think she really wanted to leave!

The volunteers work really hard in the hot summer sun right along with staff watering, feeding, and helping us care for all the desert tortoises on site. We appreciate every hour the volunteers give of their time to help out the tortoises they care for. Volunteers help us out tremendously, and we couldn’t do our job without them!

We are now gearing up for translocation season and are always looking for volunteers to help out—it’s such an awarding experience! If you are in or going to be in the Las Vegas area and wish to help with volunteering, email us at DTCC@sandiegozoo.org.

Angie Covert is a research coordinator at the San Diego Zoo Desert Tortoise Conservation Center. Read her previous post, Internship at Desert Tortoise Conservation Center.