Spiny lizard a master of disguise
Of all the reptiles and amphibians that have crossed John Karges’ path, nothing reminds the former herpetologist of home quite like the Texas spiny lizard. Growing up in Fort Worth, Karges, now a retired conservation biologist, often spotted the bark-colored reptile climbing up a backyard tree or rock wall. Then there was that time at the Brazos River while in high school when Karges and a girlfriend saw a patch-nosed snake roll down a bluff with a Texas spiny lizard squirming in its jaws.
Now years after working at the Natural History Museum of Los Angeles County, Karges finds himself getting even more up close and personal with the lizard species of his youth, this time throughout the wooded areas around his new home in San Antonio.
A Lone Star lizard from Oklahoma to Mexico. The Texas spiny lizard (Sceloporus olivaceus) inhabits much of Texas, with a range from Oklahoma well into Mexico. The arborial lizard spends most of its life in trees. They do, however, also perch on fences and poles and will hit the ground to feed and to lay eggs.
Now you see them, now you don’t. The Texas spiny lizard is a master of camouflage, thanks in large part to a black, white and red-brown chevron pattern on its back, which blends in with the trees in its habitat.
“An adult from south of San Antonio may not look like an adult in Fort Worth’s county,” Karges said. “The camo works best for wherever they’re adapted to.”
The spiny lizard’s long toes and sharp claws also help the lizard stay still while on a tree trunk, making it even tougher to spot.
The ladies wear black and the guys sport blue. Pelke said one way to determine the sex of a Texas spiny lizard is by their backs. Females have black cross bands on their back while males don’t. Another distinction: Males usually have blue patches along the edges of their belly.
Big lizards with short lives. Texas spiny lizards grow to around 8 to 11 inches long from snout to tail end, pretty big for such a lizard species. But Texas spiny lizards live only around four years in the wild, if they successfully avoid patch-nosed snakes and other predators.
A bug’s life for these “cold
blooded” killers. Texas spiny lizards are insectivorous, meaning they eat mostly insects such as beetles, grasshoppers and pill bugs. Like all reptiles, Texas spiny lizards are ectotherms or so-called “cold-blooded” animals, meaning they depend on outside sources for body heat.
Gardeners love them. Like a gardener’s guardian angel, Texas spiny lizards can spot garden insects from their perches up high and scurry down to make a meal of those pests.
The lizards are diurnal, meaning they’re most active during the daytime.
Pelke said he has at least a dozen Texas spiny lizards on his property in Cibolo that keep his
“I think when they are around people and disturbances, as long as they’re not perceived as a predator, they’re fairly tolerant of human approach,” said Karges. “It’s a comfortable neighbor.”
Texas spiny lizards certainly look more at home in and around the Alamo City and the Lone Star State.
Unlike the Texas horned lizard, the Texas spiny lizard isn’t listed as a threatened species in the state. And unlike the colorful green anole, the Texas spiny lizard keeps a low profile by blending in with its surroundings rather than sticking out. That is, until it does.
“They have a ton of character, period,” said Craig Pelke, director of ectotherms at the San Antonio Zoo. “They’re very bold, although part of that has to do with the fact that they have cryptic colorization.”
Here’s a closer took at that plucky vertebrate with serious backbone.
yards pest-free. “Due to their size, they can take down a whole variety of insects,” Pelke said. “And they just work magic for keeping the pest insects down to a minimum.”
They’ll lose their tail to save their skin. If a predator grabs a Texas spiny lizard by the tail, the tail can snap off and wiggle to distract the predator while the lizard makes a run for it. The lizard later grows a new tail, albeit shorter and paler than the original.
The guys do push-ups to win mates and keep their turf.
How’s this showing off ? Male Texas spiny lizards bop up and down in what appears to be a push-up contest to secure their territory from other males and to woo females for breeding.
“They’ll even do it to humans, which is kind of cute,” Pelke said. “Basically that behavior is to look impressive.”
Moms lay lots of eggs. Texas spiny lizards typically breed during the spring, with females laying clutches of up to 30 eggs as often as four times a year in the summer. But most of those babies won’t grow up.
“They’re quite prolific,” Pelke said, “but only 2 to 5 percent of the young reach maturity.”
The babies fend for themselves. Female Texas spiny lizards nest on the ground and ditch their eggs after hiding them. After around two months, 2-inch long babies hatch from the eggs and fend for themselves.
“As soon as they hatch and emerge, they already have all that camouflage,” Pelke said. “And they know how to use it.”
Not as famous as his horned cousin. The Texas spiny lizard may bear the name of its native state habitat, but it’s the Texas horned lizard, also known as the horned frog or horny toad, that gets a lot more love in the Lone Star State, where it’s a species of concern due to its diminishing populations.
Texas made the horned lizard the state reptile in 1993. The horned frog also is the mascot for Texas Christian University in Karges’ old stomping grounds of Fort Worth.