Reptiles and Amphibians

Dallas Zoo staffers awarded nearly $70,000 in funding from National Geographic Society for conservation work

Penguin nesting project and amphibian conservation to be funded through National Geographic Society Grants

Two of our team members will join the ranks of renowned conservationists like Jane Goodall and Jacques Cousteau, as National Geographic Explorers, working on personal field conservation projects across the globe.

Dallas Zoo’s Animal Care Supervisor of Birds Kevin Graham was awarded a $50,000 grant in support of his project: “Using Artificial Nests to Improve Breeding Success of Endangered African Penguins.” Additionally, Curator of Ectotherms Ruston Hartdegen was awarded $18,955 in support of his project: “Expanding an Amphibian Rescue Center at the Dallas Zoo.”

Kevin Graham on South Africa’s Dyer Island installing the artificial nests.

“Receiving grants of this magnitude from National Geographic Society really shows the advances our team is making in the field of wildlife conservation,” said Harrison Edell, Dallas Zoo’s Executive Vice President of Animal Care and Conservation. “These are lifesaving undertakings that Kevin and Ruston have worked at length on – they had to prove successful completion of similar projects with measurable results before being awarded the grants. Now, we can make an even bigger impact for endangered African penguins and near-extinct frogs.”

Protecting penguins

In addition to caring for Dallas Zoo’s birds, Graham has worked hard to save African black-footed penguins in South Africa for the past three years as the Artificial Nest Development Project Coordinator for the Association of Zoos and Aquariums (AZA). He leads a team that studies, designs and installs artificial nests for the penguins to lay eggs in.

Over the past 100 years, the population of African penguins has declined from more than two million breeding pairs to slightly more than 20,000 breeding pairs left – that’s a more than 98-percent population decline mainly due to improper nests that fail to protect their eggs.

African penguins burrow and nest in guano (a term for their poop), but decades ago, Europeans and South Africans began removing the guano to use as fertilizer, leaving the penguins’ eggs vulnerable to predation, human activity, and the elements. There are currently only 27 natural guano nests left.

An African penguin sits on an egg inside the artificial nest.

In February 2018, Graham joined forces with AZA scientists, the Dyer Island Conservation Trust and Pan-African Association of Zoos and Aquaria (PAAZA) to install 200 artificial nests in two South African penguin colonies. After extensively testing various artificial nest prototypes, two designs were penguin-approved. At the end of the testing period, the scientists learned that approximately 96 percent of the nests in the study were utilized by the penguins, just over 80 percent had eggs laid in them, and more than 56 percent had successful chicks.

Over the next few months, the team will build 600 more nests to install, which is where the grant funding will come into play. Long-term, Graham hopes to have 6,000-7,000 nests installed in total.

“Our vision is to eventually achieve large-scale implementation that will allow thousands of penguin pairs access to suitable nesting locations, improving the current breeding success rate, and establishing population sustainability and stability,” said Graham. “There are other threats hurting African penguins – over-fishing, climate change, and marine pollution – but it feels good knowing that right now we’re taking immediate action to save them, and if nothing else, at least we gave them a place to raise kids.”

Hopping to the rescue

With one-third to one-half of all amphibian species worldwide threatened with extinction, conservation action is absolutely critical to preserving herpetological biodiversity. The Dallas Zoo is taking the next step to develop assurance populations of three threatened amphibian species – the dusky gopher frog, the Houston toad, and the Puerto Rican crested toad.

Ruston Hartdegen releases a dusky gopher froglet back into Mississippi’s DeSoto National Forest.

This past summer, we opened a behind-the-scenes Amphibian Rescue Center where our herpetologists are working to produce healthy offspring to release back into their natural environments.

We are already leading efforts to protect the dusky gopher frog, one of the most endangered amphibians in the world. In October 2018, herpetologists released new froglets from our existing dusky gopher frog population into their native habitat of Mississippi, where the frog is endemic to only three small ponds in the DeSoto National Forest.

“Without conservation efforts like our zoological breeding program, many endangered species would become extinct in the wild,” said Hartdegen. “Amphibians are critical to our environment. Known as ‘indicator species,’ they’re used to gauge the health of their ecosystems – the moment they’re in decline, we know that habitat has been compromised due to problems like, pollution, habitat destruction, or disease.”

With the help of the National Geographic Society grant, Hartdegen is expanding the Amphibian Rescue Center to accommodate two new breed-and-release programs – the Houston toad (currently only found in three Texas counties) and the Puerto Rican crested toad (the only native toad on the island) – helping a total of three species increase their numbers while protecting genetic diversity.

A dusky gopher frog at the Dallas Zoo Amphibian Rescue Center before its release.

The National Geographic Society funding marks the first time our staffers have received support from the Society in its history. Since its inception 130 years ago, the National Geographic Society has supported the work of more than 3,000 Explorers in the field.

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Texans come together to save our state reptile

Although Texas horned lizard populations are increasing thanks to community efforts, there is still work to be done.

Head west on I-20, and in no time, you’ll notice large, red formations of sedimentary rock standing like mountains amid the mostly flat, arid earth and rolling plains. This is Rotan, Texas  – far from the impressive view of Downtown Dallas’ protruding skyscrapers. Here you’ll find many creatures that dominated these parts in the days of the Wild West still making their homes. However, the thousands of snakes, lizards and insects that are all well adapted to survive these harsh conditions, are no longer thriving as in those days not long ago.

Recently, a group of Dallas Zoo staff members, interns and volunteers took the drive to the Rolling Plains Quail Research Ranch to study one reptile who has made the ranch its home – the native and beloved Texas horned lizard. The facility was established in 2007 for the purpose of enhancing the abundance of the northern bobwhite, a ground-dwelling quail native to the United States, Mexico and the Caribbean. Rolling Plains Quail Research Ranch preserves 4,720 acres of land to maintain the natural brush cover necessary for quail conservation efforts. This undeveloped land is the ideal setting for the scaly Texas horned lizard. The brush cover provides shelter from predators, which is essential, as their toad-like bodies tend to slow them down.

Rolling Plains Quail Research Ranch in Rotan, Texas

“The area is managed for quail, with shortgrass and tallgrass prairie land, which is also vital to horned lizards and their prey, harvester ants. Horned lizards live in a similar niche as quail and benefit from the preservation of this land, as do many other animals,” Dallas Zoo reptile keeper, Shana Fredlake observes. “This is native habitat for these animals, so keeping it pristine helps this population stay stable and helps us observe their natural behaviors and monitor growth rates.”

Although the horned lizard was their primary focus, the group was also delighted by the company of a few tarantulas and snakes, even stumbling across a rattlesnake; a real treat for Dallas Zoo reptile supervisor, Bradley Lawrence who has a special fondness for the noisy, venomous reptile. Lawrence believes the conservation work being done today has also benefitted other reptile species native to Texas.

“Most folks in Texas will do anything they can to protect, donate and manage land for horned lizards. They don’t know it, but this helps conserve other species that are not looked on as favorably,” Lawrence shares.

Our research team studied Texas horned lizards in hopes of restoring their population.

The community’s willingness to pitch in and help the conservation of the Texas horned lizard is promising, but much work still needs to be done. Despite conservation efforts to reverse the decline of the species, the horned lizard remains state-threatened.

“The Texas horned lizard has disappeared from about 60% of its former range here in Texas due to invasive fire ants, over-collection, and habitat destruction,” Lawrence adds. Despite the numbers, he remains hopeful for the species: “They are charismatic, gentle reptiles, and everyone that sees them falls in love.”

“It makes me happy to see Texas have a state reptile and that people love this reptile,” Fredlake says. “If we can coexist without destroying every part of their habitat, there is a chance to bring them back to all parts of their former range.”

By studying population density, habitat preference, diet, sex ratios, and activity patterns, we’ve developed a greater scientific understanding of our state reptile and how to best contribute to its conservation. For more information about our Texas horned lizard conservation efforts, click here.

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Dallas Zoo sends help to Madagascar after nearly 11,000 critically endangered tortoises were seized from a residential home

Jorge Chavez, one of our tortoise experts, is en route to Madagascar to help with an unprecedented wildlife trafficking crisis. Last week, nearly 11,000 radiated tortoises were confiscated from a residential home in the city of Toliara, located on the southwest coast of Madagascar. This seizure is the largest for tortoises in the history of the Turtle Survival Alliance (TSA) – one of the world’s leading turtle and tortoise conservation organizations, and a Dallas Zoo conservation partner.

A portion of the radiated tortoises living on the floor of the home./Turtle Survival Alliance

Right now, the critically endangered tortoises are receiving initial in-processing, health evaluations, triage, hydration, and food at a temporary facility. Sadly, hundreds of tortoises have already died from dehydration, malnutrition, and illness.

Led by the TSA, the Dallas Zoo is part of more than 20 institutions accredited by The Association of Zoos and Aquariums that’s helping send funds, supplies and emergency assistance to Madagascar. Our team of veterinarians, vet techs and zookeepers will arrive in Madagascar this weekend as part the first of three waves of help.

Known for their beautiful shell with a striking star pattern, radiated tortoises are a valued animal in the global illegal pet trade. This species has declined by more than 80 percent in the last 30 years, leaving these tortoises vulnerable to extinction in the wild in our lifetime.

Stay posted on our Facebook page as we share Jorge’s updates from the field over the next two weeks. If you’d like to help in this rescue effort, please donate now to the Turtle Survival Alliance.

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Dallas Zoo hatches the only perentie monitor lizards in the AZA

What hails from Australia, runs as fast as an Olympic sprinter, and is the fourth largest lizard species in the world? The perentie monitor. And who is the only AZA-accredited zoo in North America to successfully hatch them? We are.

Our world-class herpetologists are welcoming three new babies. Weighing about .13 pounds at hatch, these lizards could grow to be 33 pounds and 6.5 feet long.

These little ones are our first perentie monitor hatchlings since 2001, when we became the first AZA facility outside of Australia to reproduce them.

“I am proud of the staff and excited to see hatchlings again,” said Ruston Hartdegen, Dallas Zoo’s curator of herpetology and aquatics. “It’s been a very challenging project and continues to be so. This is the culmination of many years of effort, dedication, and hard work. I look forward to seeing many more hatchlings in the years to come!”

Housing these lizards can be extremely difficult, and you can’t find many outside of Australia. In fact, only two other North American AZA-accredited zoos care for perentie monitors: Omaha’s Henry Doorly Zoo and the Los Angeles Zoo. While housing accommodations are challenging, it’s even more challenging to breed them in human care.

One of our newly hatched perentie monitor lizard babies.

“To successfully hatch this species, it takes a lot of time, attention, and care from reptile staff,” said Hartdegen. “Females also need a ton of space to nest. We actually built two large indoor habitats capable of deep nesting just for them.”

The Dallas Zoo has a lot of experience with monitor lizards, which is one reason we’ve been able to successfully reproduce perenties. Up next: Our herpetologists plan to focus efforts on crocodile monitors, a species that hasn’t been bred in North America in 20 years, mostly because of pairing issues with the animals. Dallas Zoo currently cares for ten crocodile monitors, putting us in a good position for success.

“Zoological expertise has been lost for crocodile monitors,” said Bradley Lawrence, reptile and amphibian supervisor. “We’re hoping to lead the zoo community in that soon, too.”

On your next Zoo visit, stop by the Herpetarium to see one of our crocodile monitors and congratulate our reptile keepers on their new perentie monitor babies. (We don’t have plans to make the hatchlings viewable to the public right now, but promise to let you know if that changes!)

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A teacher’s perspective: Working on Dallas Zoo’s Texas horned lizard project

A teacher measures the size of a wild Texas horned lizard for Dallas Zoo’s population research.

Dallas Zoo’s reptile keepers recently ended their eighth year studying the life history of Texas horned lizards on the 4,700-acre Rolling Plains Quail Research Ranch in Fisher County, Texas. By collecting lizard life history data, we hope to shed valuable light on the ecology of this threatened native Texan that is now in decline throughout much of its range. Earlier this year, Dallas-area teachers joined us for our first-ever Texas Horned Lizard Teachers Expedition. Teacher Cara Kailukaitis shares her story on ZooHoo! 

Reptile Supervisor Bradley Lawrence inserts a tag (similar to a pet microchip) into a lizard.

This summer, I had the pleasure of attending the first-ever Texas Horned Lizard Teachers Expedition offered through the Dallas Zoo. When I saw this on the website, I knew I had to attend. Twenty years ago I

did my high school senior research report on these amazing creatures. Finally being able to study these tough little lizards up close and handle them was very fulfilling.

I have always loved nature and as an informal educator I’ve tried to pass this along to homeschoolers. Working with young children is very rewarding and they often bring a smile to my face. But getting a chance to do actual field work with other professionals and teachers was a great change of pace.

Throughout the expedition weekend, I was able to do transect field studies, examine scat and tracks, and help find and take measurements on the Texas horned lizards. What the schedule failed to mention was

The research team, including Cara pictured third from right.

that we would be diving out of four wheelers and grabbing horned lizards as they tried to scurry away. It felt like I was living an episode of The Crocodile Hunter. All that was missing is the guy yelling “crikey!”

While I went to learn about the Texas horned lizard, I also had the opportunity to meet with the interns at the Rolling Plains Quail Research Ranch where the field trip was conducted. They shared a wealth of knowledge about not only the quail but other flora and fauna in the area.  Seeing their efforts put the techniques we were learning about, like transect studies, into perspective. Rather than being just an idea in a book, these techniques were brought to life in front of us. Their efforts to protect the quail have the added benefit of helping the lizards, as well.

All fun aside, I want everyone to know how important it is to reconnect with nature and preserve our environment. The ranch is an oasis in the middle of oil rigs and empty cotton fields. With 94-percent of Texas land in private ownership, it is doubly important that such places exist. Without this space, Texas horned lizards, quail, and many other indigenous species would be homeless.  While at the ranch I could envision the bison that once roamed across this land and wonder what animals will still be here in 50 years. I would love for everyone to make time for an opportunity like this to see just how interconnected we all are.

I’m so thankful for the opportunity the Dallas Zoo gave me to participate in this event and can’t wait for another field trip! A huge thank you to Colin Johnson with Dallas Zoo Education team; reptile keeper Shana Fredlake; and reptile supervisor Bradley Lawrence for making this trip possible, and the staff at the Rolling Plains Quail Research Ranch for all that you do to help protect this environment for future generations.

*If you’d like to be part of an Educator Workshop, check out all of our upcoming programs.

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