Posts Tagged With: Texas horned lizard

FIELD NOTES PART II: Saving our state reptile

Reptile Supervisor Bradley Lawrence guest-blogs on ZooHoo!


A Texas horned lizard spotted at RPQR last weekend.

This guest-blog is part of a series. Click here to read Part I!

Springtime is never boring on the rolling plains of Texas. Our latest expedition to the Rolling Plains Quail Research Ranch in search of Texas horned lizards (aka “horny toads”) started a little rough. We arrived just in time to get an hour or so of searching in before we were forced to call it quits for the evening due to weather. The storms were severe enough to produce baseball-size hail and at last one tornado within 5 miles of us. We spent a little time in the much appreciated storm shelter.

The next morning was very wet, windy and a little cold – not a good combination for finding Texas horned lizards, but the afternoon finally warmed up, and the day turned out to be very nice. We’ve found that when conditions are sub-optimal, we tend to see only young lizards and old lizards that are thin, injured or less than prime specimens. My personal feeling is that the adult animals that are in good condition simply wait bad days out until a better one comes along. They can afford not to feed for a few days or even weeks at a time.

We release the lizards in the same spot we found them.

When we catch a lizard, we immediately start to log a GPS location. While this is happening, we measure the total length of the animal, weigh them, and record the surface temperature and UV index at the point where we initially spotted the lizard. A small electronic “chip” is placed in the lizard so we can track home range, growth, and population density. These and some other observations are all recorded in a handheld computer/GPS.  This whole process takes about 5 min. Then the lizard is released, no worse for wear, right where it was found.

Our lizard sightings are getting more frequent as spring turns into summer – these little lizards are doing very well here. We even found our first gravid (that means pregnant or egg-carrying in reptile-speak) lizard of the season. We love to see reproduction in the wild! A large female is able to lay 40+ eggs at a time. We will start to see this year’s hatchlings toward the end of July and into August.

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

Winter is naptime for some reptiles and amphibians

Reptile and amphibian supervisor Bradley Lawrence guest-blogs on taking care of our diverse collection during hibernation months.

Bradley L bundled up

Reptile and amphibian supervisor Bradley Lawrence

Another North Texas winter is in full frigid effect — which means I layer on my warmest clothes, boots, gloves, scarves and – yes – my big, fluffy hat to keep warm. But for our reptiles and amphibians, when the temperatures drop, so do their body temperature, heart rate and digestion.

In the wild, these guys would need to find a temporary home underground or in a sheltered area where they can protect themselves and go into hibernation. Here at the Zoo, even though our reptiles and amphibians are in climate-controlled homes, we still need to take them through the motions of winter. Seasonal changes like temperature and rainfall are crucial cues to let them know when it’s time to reproduce.

Amphibians typically will lay eggs during rain events. This ensures that the eggs and tadpoles will have enough water to last through metamorphosis. Many temperate reptiles will take advantage of warm months to feed while resources are abundant, then go through a period of hibernation through the winter months. Some reptiles will breed prior to hibernation, then gestate through winter and lay eggs or give birth in the spring. Some reptiles will breed in the spring following hibernation.

At the Zoo, we have a “hibernaculum” that we use to house and carefully control the winter temperatures for those temperate animals that need a period of hibernation.  We start by gradually lowering the temperature of the animal’s enclosure and reducing the amount of food they receive. Reptiles generally need warm weather to digest food properly.

Texas horned lizard/Dallas Zoo

Texas horned lizard/Dallas Zoo

Once they have reached a low temperature, they’re taken off of food to let their bodies completely digest and process the food already in their system. Then, after a veterinary exam to ensure they are healthy enough to hibernate, they are placed in the “hibernaculum.” Here, the temperature for some of our snakes can be taken down to as low as 45 degrees.

The Texas horned lizard, a very high-profile lizard in our collection, is one reptile that requires a period of hibernation in order to reproduce. They are all in the hibernaculum now at about 49 degrees. We’ll slowly raise the temps in March to bring them out of hibernation. Then the males and females will be put together for breeding, helping to ensure the survival of this iconic Texas species.

Categories: Conservation, Reptiles and Amphibians, Veterinary Care, Zookeepers | Tags: , , , , , , | 2 Comments

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