Reptiles and Amphibians

Rat snake study the longest of its kind at Dallas Zoo

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For more than 20 years, the Dallas Zoo has studied an animal that doesn’t even have a permanent home inside Texas’ largest zoo.

The Texas rat snake (P.obsoleta) slithers (and climbs!) onto the Dallas Zoo grounds every spring in search of food. These snakes, while not venomous or harmful, may alarm Zoo guests because of their large size.

Since 1989, Zoo herpetology staffers have captured, marked, examined, and released the snakes away from Zoo animals and guests. It’s the longest study of urban snakes of any kind.

Wait, releasing the snakes?!?

“They’re completely harmless, big snakes that eat a lot of rats,” Herpetology Supervisor Bradley Lawrence said.

Given that a female rat can produce hundreds upon hundreds of babies, Texas rat snakes are like Dallas Zoo junior staff members, keeping the rat population maintained. Because the Zoo sits on more than 100 acres of heartland prairie forest, rats are simply part of the ecosystem.

The snakes are tracked with digital transponders, the size of a grain of rice, inserted just below the skin. This transponder identifies the individual snake with a unique number. When a snake is found, reptile keepers scan for the transponder and note weight, length, sex, and physical description. They also add notes of what they find: “Swallowed decoy egg … Regurgitated fledgling bird.”

Texas rat snakes that find themselves with injuries or other ailments (like swallowing a decoy egg, used to encourage nesting) get an extra-long stay at Château Dallas Zoo to see our veterinarians before being released back in the wild.

Since tracking began, 20 different snakes have been caught repeatedly over four-year periods, and two snakes have lived around the Zoo for more than seven years.

The data, which has more than 1,000 captures, is teaching Zoo herpetology staff about how these urban-environment reptiles live.

“We want to learn growth rates, what they prey on, their movement pattern, and how urban spaces affect their population,” Herpetology Curator Ruston Hartdegen said.

Don’t be alarmed if you see a Texas rat snake, at the Zoo or anywhere else in Dallas. If you’re visiting us, just alert Zoo staff and we’ll happily scoop the snake up to be examined, released and tracked.

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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.

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An adult dusky gopher frog.

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License plates to save mysterious Texas water snakes

A baby Brazos water snake photographed by DFW Herpetological Society president Mark Pyle.

A young Brazos water snake photographed by DFW Herpetological Society president Mark Pyle.

With 42,000 miles of water to inhabit, you’d think the Brazos water snake would be living the dream in Texas’s longest river. But the Brazos River is ever-changing, and human influences have left few habitat options for this elusive snake that’s exclusive to its water, and only resides along its rocky stream beds and banks.

Next spring, Dallas Zoo’s herpetologists will embark on a year-long field research project to bring much-needed light to the Nerodia harteri population – commonly known as the Brazos water snake, which is one of only three snake species endemic to Texas. And it’s all thanks to Texas Parks and Wildlife Department’s conservation license plates.

The Horned Lizard License Plate program supports wildlife conservation projects across our state./Texas Parks and Wildlife

The Horned Lizard License Plate Program supports wildlife conservation projects across our state./Texas Parks and Wildlife

While driving through Texas, you’ve probably spotted a super-rad license plate featuring a Texas horned lizard, or a flying hummingbird, or possibly a rattlesnake. These specialty plates fund important field projects across our state to benefit wildlife diversity and protect native non-game species.

The Dallas Zoo’s herpetology team recently was awarded a $4,500 grant through TPWD’s license plate program to spearhead a population assessment on this threatened water snake.

In recent years, Brazos water snake population surveys have been unsuccessful after very few snakes could be found. But a recent chance discovery of a potential population in Lake Granbury, an artificial lake damming the Brazos River, has local herpetologists beaming with excitement.

“DFW Herpetological Society president Mark Pyle lives near Lake Granbury and spotted the little brown snakes that no one pays much attention to,” said Ruston Hartdegen, Dallas Zoo’s curator of herpetology. “Now that a potential population has been discovered, we have a chance to make a direct and significant impact just an hour outside the zoo.”

These small snakes average 20-30 inches long./Mark Pyle

These small snakes average 20-30 inches in length./Mark Pyle

Come April, the Dallas Zoo’s reptile team will be on the ground armed with dip nets, searching for the mysterious snakes. UT Arlington and TPWD also will join in field efforts. When the team spots one of the small serpents, they’ll note the exact location and activity: swimming, basking, feeding, or hiding. When it’s captured, they’ll record its gender, snout-to-vent length, total length and weight, then insert a passive integrated transponder (PIT) tag to identify the snake (similar to the chip inserted in cats and dogs).

“Some researchers have spent hundreds of man hours searching for these snakes and have only found a half-dozen,” Hartdegen said. “We now have an opportunity to understand one of Texas’s most rare and habitat-restricted species.”

Brazos water snakes are viviparous, meaning they give birth to live young./Mark Pyle

Brazos water snakes are viviparous, meaning they give birth to live young./Mark Pyle

It’s a conservation partnership that will help decide how these misunderstood native Texans will be protected. Stay tuned here on ZooHoo! this spring for video and photo updates from the field!

You can help, too: Buy your Texas conservation plate for only $30, and $22 of that fee goes directly to research projects like this one.

Categories: Conservation, Reptiles and Amphibians, Zookeepers | Leave a comment

10 animals who wear fall well

Forget the flannel, cable-knit sweaters, and scarves – no one knows fall style better than the animal kingdom. We’re laying down some fall fashion with 10 animals who make this season look better than ever.

1. African crowned cranes rock autumn’s trendiest hairdo like fall royalty. They sport a golden crown of feathers atop their head, distinguishing them from other cranes. Their red neck wattle adds a nice splash of color, too.

African Crowned Crane2. A creature that resembles a large, ripe tomato deserves a major autumn accolade. Tomato frogs are brightly colored to warn predators that they’re not good to eat – but we think they’re juicily good-looking.

_MG_9734 Tomato Frog CB3. Giraffes’ spotted coats prove nature has a sense of style. Within all nine giraffe subspecies, each individual’s markings are as unique as our fingerprints. The reticulated giraffe subspecies, which you’ll find at our Zoo, sports a dark coat with a beautiful web of fine white lines.

4. Because no other animal can model a bed of fall leaves as adorably as our African pygmy hedgehog. These tiny guys use their coat of spines to escape predators – they’ll curl up into a tight ball and their spines will raise, forming a protective barrier.

Hedgehog-African Pygmy5. African red river hogs got it goin’ on. From their striking coloration and prominent tassels on their ears, to the hairy white Mohawk running along their spine, these hogs wear fall like no other.

Red River Hog Hank6. Yellow and black has never looked so good. Amiright? Tiger salamanders’ colors and markings vary throughout their wide North American range, but their most common marking resembles the striped pattern of their big cat namesake.

Tiger Salamander7. Golden lion tamarins rock nature’s fieriest coat. These small monkeys get their name from their vibrant reddish-orange fur and the long hair round their face that forms a perfect mane.

IMG_1599 Golden Lion Tamarin CS8. The chestnut-breasted malkoha manages to flaunt every fall color flawlessly. Males and females have near identical plumage, and wear those red eye patches like bosses.

ChestnutBreastedMalkohaMilkyEyelashes9. Tigers totally own fall. Their symbolic stripes act as camouflage in high grasses or dense forests. Sumatran tigers, like our boy Kipling, have the darkest orange coat of any tiger subspecies.

Kipling10. Thanks to our fall-loving chimps, playing in foliage has never looked so good.

Categories: Birds, Chimpanzee, Giraffe, Mammals, Monkey, Reptiles and Amphibians, Tigers | Leave a comment

Girl Scout saves tortoise from water bottle

10-year-old Gracie Wakefield saves our tortoise from ingesting water bottle.

10-year-old Gracie Wakefield saves our tortoise from ingesting water bottle.

A day spent at the zoo is a privilege, time well-spent in the presence of majestic, threatened and endangered animals who deserve our respect, compassion and conservation.

The recent actions of 10-year-old Gracie Wakefield of Garland, Texas, show that she feels the same way. A normal Dallas Zoo day for the proud Girl Scout of Northeast Texas and her mom, Cindi, turned into a rescue mission when Gracie discovered a Galapagos tortoise eating a plastic water bottle.

“I first heard the plastic crunching. Then I saw half a water bottle hanging out of its mouth,” Gracie explained. “I ran down to the insect house and told them to radio for help. A reptile keeper ran over and took the bottle out.”_MG_0355

Several small pieces of plastic were removed from the tortoise’s mouth.

Reptile keeper Shana Fredlake says trash dropped by guests or blown into the Zoo gets into the wrong mouths too often. “Every day, I’m picking up plastic spoons, chip bags, water bottles, you name it,” she said.

And on a few occasions, our vets have had to remove foreign objects. “It’s terrible for their intestines because this stuff doesn’t break down,” Fredlake said.

Reptile keeper Shana Fredlake

Reptile keeper Shana Fredlake says picking up garbage from the tortoise habitat is an every day task.

Some simple advice from Gracie could help keep animals from getting hurt, both in the Zoo and outside of it: “Hold on tight to your water bottle so you don’t accidentally drop it. And don’t litter, because no one wants to see an animal hurt. I really like animals and I was so scared for that tortoise.”

We’re extremely thankful for Gracie’s quick response, and we hope all children are such good stewards of our environment and protectors of our animal kingdom.

Littering some numbers

  • Given how busy we are, anywhere from 10 to 40 park services staffers work daily to keep our 106-acre park clean.
  • 182 trash and recycle receptacles are placed throughout the zoo, ready to welcome your waste.
  • “Please don’t litter” reminders can be found throughout the park.
  • And another friendly reminder resides on your zoo map – so don’t let that become litter, either!
Categories: Conservation, Education, Guest Services, Reptiles and Amphibians, Veterinary Care | Tags: , | 3 Comments

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