Posts Tagged With: herpetology

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!)

Categories: Reptiles and Amphibians | Tags: , , , , , | Leave a comment

Working towards a ribbiting recovery: Rescuing the dusky gopher frog

An additional pond created for the dusky gopher frog in DeSoto National Park

An additional pond created for the endangered dusky gopher frogs in DeSoto National Forest.

It was nearly a year ago that Ruston Hartdegen, the Dallas Zoo’s curator of Herpetology, found himself driving deep into the pine woods of the DeSoto National Forest on a mission to save a species on its last leg – the dusky gopher frog.

While the origional 180 tadpoles that Hartdegen picked up have now metamorphed into frogs, the Zoo’s work is not done yet. The dusky gopher frog isIMG_9163 Gopher Frog CS still considered critically endangered with populations endemic to only Glen’s Pond, Mike’s Pond, and McCoy’s Pond within the DeSoto National Forest in Mississippi.

These spotted amphibians will remain in human care at the Zoo until the U.S. Fish and Wildlife Service has finished developing a full recovery plan for the species. Though the Zoo will retain a number of the frogs as part of the Species Survival Plan program, the U.S. Fish and Wildlife Service is working to identify suitable places for the experimental re-introduction of this species, possibly beginning in 2018.

“The current remaining wild populations are very limited and under intense monitoring. Previous habitats where animals have been extirpated are not likely to recover in a short period of time,” said Hartdegen.

The tadpoles await transport in the research lab at the DeSoto National Forest.

The tadpoles await transport in the research lab at DeSoto National Forest.

In late January, it was Bradley Lawrence, the Zoo’s reptile and amphibian supervisor, who found himself making the nine hour drive back to

the remote Mississippi coast to pick up more tadpoles – but transporting a critically endangered species is no easy task, even the second time around.

The Zoo received four groups of thirty-two tadpoles – over 120 dusky gopher frogs in total. Each group of tadpoles comes from a separate egg mass, meaning that these groups are all of different parentage. In order to drive the tadpoles to the Zoo, these groups were each placed in five gallon buckets filled with water. Using an air pump, oxygen was run to each of the containers for the duration of the trip.

“I tried desperately to keep the tadpoles from shifting around on the drive back. I stopped every couple of hours to check on them,” said Lawrence. “Ultimately, they all made it here safely.”

Like their predecessors, these dusky gopher frogs will be part of the Species Survival Plan program. In the future, some will likely be used in

Bradley Lawrence snaps a selfie with the precious cargo en route to Dallas.

Lawrence snaps a selfie with the precious cargo en route to Dallas.

breeding efforts while others may be released back into their native longleaf pine wetlands – an ecosystem that has been devastated by continued habitat loss. But conservation efforts shouldn’t start and end at the Zoo gates; there’s plenty that you can do at home.

“Many of the world’s amphibians can be helped in the same way whether you live in Texas, Central America, Africa, or wherever: conserve water, don’t pollute, and recycle,” says Lawrence. “Water pollution, loss of habitat, and depleted ground water all hurt amphibian populations.”

Check out these conservation tips from our Green Team that you can follow at home in order to help save the dusky gopher frog.

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‘Living fossils’: Meet our rare reptiles from the dinosaur eras

IMG_3681-Tuatara 4x6

What if we told you dinosaurs were living right here is Dallas? That would sound crazy, right? Well, it’s true.

While they’re not the towering, fierce giants of the Jurassic that you’re picturing, tuataras are the only surviving member of a distinct reptilian order, Sphehodontia, which lived alongside early dinosaurs 200 million years ago in the Upper Triassic period.

Māori priest blesses the tuataras during Dallas Zoo’s welcome ceremony.

Their small size and dusty brown scales may not catch the eye of many Zoo visitors, but these “living fossils” have one of the most fascinating stories of all of our residents. Don’t be fooled by their scaly skin and long tails – the tuatara isn’t your average lizard!

Tuataras are incredibly rare. They are found only in remote areas of New Zealand or in a few lucky institutions across the globe. The Dallas Zoo is one of only four U.S. zoos to receive permission to host the rare reptile. Not only does the New Zealand government have to grant approval for the export, but a tribe of native New Zealanders also must agree that the export has direct benefits to the species in the wild. When the tuataras arrived here in 1992, a Māori priest came along with them to perform a special blessing for the animals in their new home.

They may have lived through the extinction of dinosaurs, but unfortunately tuataras aren’t indestructible. Oddly enough, one of the biggest threats to their survival is small enough to fit in your hand – rats! Tuatara eggs must incubate 12 to 15 months before hatching, which gives the rats and other predators plenty of time to sneak into the den to steal a snack.

IMG_3692-tuatara-4x6Fortunately, it’s not too late to save these animals from extinction. The Dallas Zoo has donated thousands of dollars to our tuatara conservation partners in New Zealand to fund work in their natural habitat. Because tuatara eggs are so vulnerable in the wild, one of the best ways to ensure the survival of this species is through zoological breeding programs.

“We’re thrilled to be able to work with tuataras and have the opportunity to share with the public a totally unique and ancient lineage of reptile found in very few facilities across the globe,” said Ruston Hartdegen, Dallas Zoo’s curator of herpetology.

We are fortunate to have not one, but three tuataras in our care, and we hope to see that number rise soon. Unlike most reptiles, tuataras don’t breed until they’re 13 to 20 years old, and our two females and male have reached maturity. Veterinary staff recently performed a check-up and are happy to report that all three are in great health. With a little luck and a lot of patience, we hope to welcome the next much-needed generation of tuataras.

 

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Hopping to the rescue: Protecting the critically endangered dusky gopher frog

IMG_9168 Gopher Frog CS

For eight hours, Ruston Hartdegen drove. Through the flatlands of East Texas, then the red clay of northern Louisiana, and finally into the thick pine forests of Mississippi.

The Dallas Zoo’s curator of Herpetology was on a mission years in the making – a tadpole rescue mission.

His journey ended deep in the DeSoto National Forest, an hour north of Gulf Coast, where he gathered 188 dusky gopher frog tadpoles to bring back to the Dallas Zoo – not for exhibit, but to save them from extinction.

In 2012, the International Union for the Conservation of Nature (IUCN) named Rana (Lithobates) sevosa one of the top 100 endangered species in the world, with only 100 to 200 adults remaining.

The longleaf pine forest habitats that dusky gopher frogs call home are disappearing as paper companies harvest the trees and replace them with faster-growing loblolly and slash pine. Today, the dusky gopher frog has only a few homes in the wild remaining, including the geographically isolated Glen’s Pond.

The Zoo's biosecure facility is an asset to growing and breeding the dwindling gopher frogs.

Zoo staff are required to wear special suits and boots to enter the quarantined gopher frog facility.

The Dallas Zoo and more than a dozen other institutions are participating in a Species Survival Plan to breed and raise these 3-inch-long, dark-spotted victims of deforestation. The plan is a kind of zoo-backed insurance policy to help the species survive: Should wild populations continue to decline, the frogs raised at Dallas, Detroit, Memphis and other participating zoos could be released to bolster numbers.

“Amphibian decline is a global phenomenon,” said Hartdegen. “One out of every three species of amphibians is under serious threat. Our involvement with the gopher frog SSP allows us the opportunity make a significant difference for a critical endangered species in our backyards.”

The Dallas Zoo was invited to participate because of the unique, biosecure facility available in ZooNorth’s herpetarium.

The tadpoles, which began as eggs at Glen’s Pond, were transferred to holding tanks at Harrison Experimental Forest Station before being collected by Hartdegen. After a long drive home, they are now in an isolated quarantine space at the Dallas Zoo, being cared for by the herpetology staff.

But the efforts don’t stop there.

“Protection of habitat is crucial to saving a species,” said Matt Vaughan, the Dallas Zoo’s assistant supervisor of Herpetology.

Hoping to keep dusky gopher frogs from disappearing from the earth, the U.S. Fish and Wildlife Service has designated nearly 6,500 acres of land in Louisiana, Alabama, and Mississippi as critical habitats for them. Longleaf pine restoration efforts also are under way.

The partnership between governmental agencies and non-profit zoos will give these struggling little creatures a chance to beat the odds, and the Dallas Zoo herpetology team is proud to be on the front lines in this crucial conservation effort.

Matt Vaughan and Anna Campitelli contributed to this story.

IMG_3453 Gopher Frog Tadpoles CS

Gopher frog tadpoles are examined by a reptile keeper.

IMG_9163 Gopher Frog CS

An adult dusky gopher frog.

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