Texas Horned Lizard, Once Common, Now Must Be Captive Bred

The horned lizard, the state reptile of Texas, is up against a myriad of threats. Scientists are hoping reintroduction will help it survive.

October 3, 2018 – These bumpy reptiles are Texas horned lizards, also known as “horny toads.” Once common in Texas, the lizard is now a threatened species there. The beloved state reptile has two large horns on its head, and though it’s mostly docile, it can shoot blood from its eyes when threatened.

Biologists with the Texas Parks and Wildlife Department and three area zoos have been working together to save the horned lizard.The zoos have begun captive breeding programs, with a goal to replenish the wild population. In September, around 140 hatchlings were released in Mason Mountain Wildlife Management Area in Texas. Biologists hope the breeding and reintroduction program eventually will lead to self-sustaining populations.

Texas Horned Lizard, Once Common, Now Must Be Captive Bred

The horned lizard, the state reptile of Texas, is up against a myriad of threats. Scientists are hoping reintroduction will help it survive.

October 3, 2018 – These bumpy reptiles are Texas horned lizards, also known as “horny toads.” Once common in Texas, the lizard is now a threatened species there. The beloved state reptile has two large horns on its head, and though it’s mostly docile, it can shoot blood from its eyes when threatened.

Biologists with the Texas Parks and Wildlife Department and three area zoos have been working together to save the horned lizard.The zoos have begun captive breeding programs, with a goal to replenish the wild population. In September, around 140 hatchlings were released in Mason Mountain Wildlife Management Area in Texas. Biologists hope the breeding and reintroduction program eventually will lead to self-sustaining populations.

Maybe it’s a butterfly you don’t see in your garden anymore, or a bird whose song you don’t hear in the summer. Many of us know of one or more animals we grew up with that just aren’t around anymore, or seen rarely. They may not be endangered but they could be headed that way.

That’s the case with the Texas horned lizard, the state’s official reptile and one of 1,300 species of concern in Texas alone, says Tom Harvey at the Texas Parks and Wildlife Department (TPWD).

Numbers of the so-called horny toad have dropped so sharply that the reptile has been declared threatened in Texas, and steps are being taken to save it. The Forth Worth Zoo has started a horned lizard captive breeding program; the hatchlings, around two weeks old in this video, are being released into the wild in the hopes that flooding the landscape with baby lizards will ensure their survival.

“The plan now is to produce large numbers of offspring that will hopefully enable them to get ahead of the predators,” says Diane Barber, ectotherm curator at the zoo. “Last year we reintroduced 63 hatchlings; this year we released 93.”

Past experience shows that most won’t survive. “With amphibian reintroduction programs, as well as sea turtle programs, it is accepted that less than one percent of offspring from a female will survive to adulthood to breed,” she says.

Stressors

Horned lizards used to be widespread in Texas but have been in gradual decline for the last few decades. Several factors have contributed, such as urban development, which has fragmented the landscape, robbing the reptiles of space and pressuring populations of the harvester ants they feed on. And that’s not all.

“The introduced red imported fire ants will kill hatchlings,” says Barber, as well as harvester ants. “As green spaces shrink, some predators become more abundant or consolidated.”

Female horny toads can lay a lot of eggs—20 to 30 a year—but those factors reduce hatchling survival rates.

For over a decade Texas conservation experts have relocated adult and baby lizards from parts of the state where they were plentiful to parts lacking in lizards. But that grew expensive, and many were lost to predation, despite their impressive arsenal of defense weapons.

When faced with predators, they can shoot foul-tasting blood out of their eyes, though they will only do that to members of the dog family. Another effective technique is to sit very still in an effort to blend in with the rocks they're perched on.

Recovering Wildlife

A bipartisan bill wending its way through Congress, called Recovering America’s Wildlife Act, aims to get out ahead of animals like the horny toad that are in decline—to prevent them from ever becoming threatened or endangered. It would redistribute $1.3 billion among states for the effort from funds that already exist in other federal programs.

The act, which has 93 co-sponsors to date, has widespread support in conservation circles.

“Congress has a lot to do, but we’re cautiously optimistic that lawmakers can tackle this and other conservation issues before the end of the year,” says Mike Saccone of the National Wildlife Federation.

Others say the legislation has loopholes. For example, Defenders of Wildlife, on its website, notes that the bill contains provisions that don’t guarantee funds will actually be spent on species conservation.

But there’s a history of success with states—mostly using funds from hunting licenses and taxes—restoring species that were decimated in the early 1900s but are plentiful now, like white-tailed deer, striped bass, and turkey. That raises hopes that this plan could work for other species.

“Conservationists have been trying to get protections for non-game animals for years,” says Harvey of the TPWD. “The horned lizard is kind of a poster child for hundreds of other wildlife species that were once common but are now rare.”