There are three species of horned lizards known from this range.
The texas horned lizard is the largest of the horned lizards in the state and is found throughout the range of this work. In many areas they are not as common as they were fiteen or twenty years ago. Part of this is because of habitat disruption, but much of the decline is due to the advent of fire ants. Fire ants have drastically reduced the numbers of many types of animals over the last two decades.
Twenty years ago I used to see horned lizards scuryying across highway 90 in Del Rio in the late afternoon. I have not seen a horned lizard in the Del Rio area for six or eight years.
I have found the most clearly patterned and the largest Texas horned lizards in Culberson County. Specimens 5 - 6 inches long are common there, and I have found several over seven inches tip to tip.
They are most commonly found basking in the early morning and late afternoon.
This specimen is from near Van Horn, Culberson County.
This pair was found mating on Hwy.54 at about 10 PM. They seem to be lighter in color at night.
The roundtail horned lizards are found throughout the range of this work. They are small, roundish lizards, seldom over four inches tip to tip.
Most of the ones I have seen have been basking on dirt roads at late afternoon and early evening. This one was found on the pavement near Van Horn after it was hot enough for the Texas horned lizards to go to cover.
The modestum are very variable in color, usually adapting to the colors of the area. These specimens are from Hwy. 54, Culberson County. The first one is over five inches long, and was found basking about 10 AM, when it was getting quite hot. The smaller one, about 3.5 inches, was found at night and is more like the ones you will normally see.
The mountain short-horned lizard is currently reported from two limited populations, one in the Davis Mountains and one in the Guadalupe Mountains.
Andy reports "We were in GMNP in May of 2007 hiking on the Juniper Trail. It's in the higher elevations at about 5000ft... As you'll see from the pics, he was well hidden....I think I was just lucky to see it because I was not specifically looking for it. I was looking down to make sure there were no snakes hanging out in the middle of the trail! And there he was, right next to the trail."