Lizards

Eastern collared lizard

NPS/CA Hoyt

 

The males display brighter colors

NPS/CA Hoyt

Chihuahuan Greater Earless Lizard

Cophosaurus texanus scitulus
Known for their high tolerance of heat, greater earless lizards are found throughout the park from the Rio Grande floodplain to the foothills of the Chisos Mountains. They can often be seen basking on the roads at night. True to their name, they have no external ear openings. Their lifespan ranges from 1 to 3 years. The primary reason for their short lifespan is the failure to keep warm throughout the months of hibernation. They love the heat!

 

They can squirt blood from their eyes

NPS/CA Hoyt

Texas Horned Lizard

Phrynosoma cornutum
This lizard prefers grasslands, plains, and desert and has been found in several locations in the park, including Panther Junction and Nine Point Draw. Their diet mainly consists of harvester ants, and a single Texas horned lizard can consume from 30 to 100 ants per day. Since the 1960s, they have declined throughout central Oklahoma and Texas. The urbanization of their habitat, collection as pets, and the loss of their main food source have all contributed to their decline.

 

Look for 4 horns at the back of the head

NPS Photo

Round-tailed Horned Lizard

Phrynosoma modestum
These lizards are found in desert flats with sparse vegetation, from the Rio Grande to the Chisos mountains foothills. They are often found near ant mounds, as ants make up more than 50% of their diet. In general, they are similar in color to the surrounding rocks or ground cover. When threatened, round-tailed horned lizards tend to flatten themselves and sit in place, or they will hunch their backs to resemble stones.

 

Can run rapidly on their hind legs

NPS/CA Hoyt

Eastern Collared Lizard

Crotaphytus collaris
A lizard not commonly seen in the park, the eastern collared lizard prefers open desert with boulders, rocks, and sparse vegetation. It can be found in the lowlands and foothills of the Chisos Mountains, including Pine Canyon, Panther Junction and lower Green Gulch. Eastern collared lizards are mainly insectivorous and carnivorous, but their diet may consist of plant material. They can vary their diet depending on what is abundant, and have been seen waving their tail in a cat-like fashion before grabbing prey.

 

Adult coloration

NPS Photo

Great Plains Skink

Plestiodon obsoletus
The Great Plains skink is large for a skink and their coloration and pattern changes from hatchling to adult. The hatchlings are jet black with dark blue tails and white spots on the head. They are vulnerable to drying out, which influences their distribution and habitat use. In Big Bend they are often found near springs or seeps with sandy to gravelly soils suitable for burrowing. Although they are sometimes active on the surface, most of the time this skink hides under large rocks, agaves, logs, or other surface debris.

 

Juvenile coloration

NPS Photo

Short-lined Skink

Plestiodon tetragrammus brevilineatus
The short-lined skink is found throughout the park, except for possibly the highest parts of the Chisos Mountains. Like the Great Plains skink, they are found near moisture, often hanging out under rocks, agaves, sotols, boards, and logs near springs, seeps and pools in canyons. The individual pictured here is a juvenile, adults become a consistent overall brassy color.

 

Hanging out on the lichen

NPS/CA Hoyt

Crevice Spiny Lizard

Sceloporus poinsettii poinsettii
A large lizard that is found in the rocky highlands of the Chisos Mountains and foothills, with a few records from the river canyons. Crevice spiny lizards prefer rocky terrain in arid and semi-arid enviornments where they are commonly seen on boulders, in canyons and in rocky outcrops. Active and very quick, they are out during the day but will retreat to a crevice when threatened.This species feeds on insects and tender vegetation.

 

They prefer to wait and ambush prey

NPS/CA Hoyt

Southwestern Fence Lizard

Sceloporus undulatus cowlesi
Southwestern fence lizards are commonly found climbing trees, shrubs, yuccas, or other upright vegetation. They can sometimes be seen on logs, boulders, buildings or signs. These lizards are widespread throughout the park, from the Rio Grande to the Chisos Mountains and foothills. Males have two large, bright blue patches on the belly and the underside of the throat is marked with two blue blotches. They feed on a variety of insects including termites, ants, beetles, flies, wasps, and grasshoppers, but will also eat spiders, snails and small lizards.

 

Invasive species

NPS/R. Negele

Green Anole

Anolis carolinensis
Invasive species
The green anole was introduced at Rio Grande Village and has become established near the beaver pond where they can hide in the thick vegetation. They are not native to West Texas, and were originally found in the southeastern United States. It is primarily an arboreal lizard, and within natural habitats it is found on tree branches, in tall grass and on shrubs. They feed on a broad range of prey and will often attempt to eat anything smaller than their own head. Green anoles are classified as insectivores, but will eat spiders, mollusks, grain, and seeds when available.