Passport to Texas

Horned lizard

Identifying Good Horned Lizard Habitat Play Now | Play in Popup | Download

This is Passport to Texas

Urbanization and invasive species are two impacts that’ve led to the decline of the iconic Texas horned lizard. The San Antonio Zoo plans to eventually release lizards from its captive breeding program into the wild.

Management is the first step in this process.

Andy Gluesenkamp is Director of Conservation at the zoo. He says he and his staff will consider environmental factors before releasing lizards onto a property.

One is: are they within the historic range of the species. Two is: are there horned lizards there now? This is a really important question. Because if there are horned lizards on that property, then that’s really a matter of managing existing populations. And I tell landowners that they are much better off than having to try and start anew and establish a population where one doesn’t exist. Other criteria are the size of the parcel; is there enough habitat for the lizards that—if we get a population established—that it will not just persist. The idea for them is to metastasize out into other habitat. And so, we’re putting lizards back onto the landscape, and not just on parcels of the landscape.

Andy Gluesenkamp says he uses high-resolution satellite-based maps from the Texas Parks and Wildlife GIS department to help assess whether areas have quality habitat for newly minted lizards.

We receive support in part from RAM Trucks: Built to Serve

For Texas Parks and Wildlife…I’m Cecilia Nasti.

A very handsome Texas Horned Lizard.

Horned Lizard Decline Play Now | Play in Popup | Download

This is Passport to Texas

Once a common sight in Texas, horned lizards are in decline. The past three decades of urban development coincide with their disappearance.

Not a coincidence at all. And although there’s no single smoking gun in the decline of horned lizards, generally urbanization is a common factor.

Andy Gluesenkamp is Director of Conservation at San Antonio Zoo, where he developed and oversees a horned lizard breeding program. Urbanization is just one impact.

There have been other, less obvious impacts. Like the introduction of non-native invasive grasses. [It] fundamentally changes the landscape from a lizard’s perspective. A lot of the grasses that we would look at and think that’s perfectly normal Texas grassland habitat, is kind of like an impenetrable bamboo thicket for these guys.

Such habitat changes mean lower diversity and density of arthropods, the lizard’s prey base. And then, there’s the red imported fire ant.

Although they’re not a deal-breaker for horned lizards, they’re not good for horned lizards. And a lot of places where horned lizards used to occur, there are now too many red imported fire ants for them even to get stablished in those places anymore. The red imported fire ants tend to eat the young as soon as they hatch out of the eggs.

Horned lizards from the San Antonio Zoo breeding program will be released back into the wild. But that takes planning. Details next time.

For Texas Parks and Wildlife…I’m Cecilia Nasti.

Texas Horned Lizard

San Antonio Zoo's Horned Lizard "Factory" Play Now | Play in Popup | Download

This is Passport to Texas

The horned lizard, or horny toad, is a charismatic creature and beloved by Texans of a certain age.

Mostly people my age. So, anyone that wasn’t around in the eighties probably hasn’t seen a horned lizard in the wild.

That’s Dr. Andy Gluesenkamp, Director of Conservation at San Antonio Zoo. Let’s just say he’s not a millennial. Andy heads up a horned lizard breeding program at the zoo, which is where I visited him in early October of last year.

We are in the main room of the conservation center. And if you look around the walls, there are rack after rack of ten-gallon aquariums. Each one with a Texas horned lizard in it. And this is what I like to call the beginning of our horned lizard factory.

You might wonder why we need a horned lizard factory—or breeding program—for the Texas State Reptile. Truth is: the little critters are getting scarce.

Although horned lizards are still doing really well in parts of their range, they’ve disappeared from about a third of their range in Texas. And that just so happens to be that portion of Texas where most Texans live.

Urbanization and the introduction of non-native grasses impact horned lizard populations. Andy Gluesenkamp says once lizards reach maturity, they will be released into areas that can support them.

We receive support in part from RAM Trucks: built to serve.

For Texas Parks and Wildlife…I’m Cecilia Nasti.

Texas Horned Lizard

TPW Magazine -- Texas Horned Lizard Play Now | Play in Popup | Download

This is Passport to Texas

With a flat, spiky body, the Horned Lizard has captivated the generations of Texans.

Everyone you meet, if you just mention horny toad, or horned lizard, they say” “Oh, I used to see those all the time when I was a kid; I would pick them up and put them into my pocket. But now I never see them. What happened to them”?

That’s a question editor Louie Bond addresses in an article for the December issue of Texas Parks and Wildlife magazine. To get answers, she travelled to the San Antonio Zoo to meet with director of conservation, Andy Gluesenkamp.

And he is raising horned lizards in hope of having babies in a few months, and putting them back into their historic habitats.

Which includes arid and semiarid habitats in open areas with sparse plant cover. This habitat’s been fragmented by development. But it still exists.

We’re actually tying into a whole other program at the agency, which comes from the mapping department. And we have this incredible interactive vegetative map of the whole state, broken into pretty small parcels of land. The biologists can look at the map and judge the habitat by a variety of criteria. So, they actually can rate each piece of land and make sure that it actually does have all the things that are needed there.

The horned lizard article by Louie Bond is as fascinating as the animal itself. Read this in-depth feature in the December issue of Texas Parks and Wildlife magazine. On newsstands now.

For Texas Parks and Wildlife, I’m Cecilia Nasti.