Texas Horned Lizard
Phrynosoma cornutum
Summary 4
The Texas horned lizard (Phrynosoma cornutum) is one of about 14 North American species of spikey-bodied reptiles called horned lizards. P. cornutum ranges from Colorado and Kansas to northern Mexico (in the Sonoran desert), and from southeastern Arizona to Texas. Also, isolated, introduced populations are found in the Carolinas, Georgia, and northern Florida. Texas horned lizards may also be native to Louisiana and Arkansas.
Description 5
The Texas horned lizard is the largest-bodied and most widely distributed of the roughly 14 species of horned lizards in the western United States and Mexico. The average Texas horned lizard is 69 mm (2.7 in) in snout-vent length, but the upper boundary for males is 94 mm (3.7 in) and for females it is 114 mm (4.5 in).
Behavior 5
Despite the fierce appearance, Texas horned lizards are extremely docile creatures. The Texas horned lizard is a sunbather, and requires bright sunlight to produce vitamin D. Deprived of sunlight, the animal is unable to produce vitamin D and can suffer from vitamin deficiency. So, horned lizards are most often found along the side of roads or other open, rocky areas, where they can lounge and take in sunlight. At night, the lizard buries itself in sand. Although they prefer to move very little, horned lizards can move quite fast if they feel a predator is in the area, and dart into thick grass and foliage to escape. Horned lizards are also excellent diggers, and can quickly burrow underground to escape threats. Horned lizards are often found near harvester ant hills which are a major part of their diet.
Although its coloration generally serves as camouflage against predation, when threatened by a predator, a horned lizard puffs up and appears very fat, which causes its body scales to protrude, making it difficult to swallow. The Texas horned lizard, along with at least three other species of the genus Phrynosoma, also has the ability to squirt an aimed stream of blood from the corners of the eyes and sometimes from its mouth for a distance up to 5 ft (1.5 m). They do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the eyelids. This not only confuses would-be predators, but also the blood is mixed with a chemical that is foul-tasting to canine predators such as wolves, coyotes, and domestic dogs. This novel behavior is generally observed to be very effective in defense; however, it appears to have no effect against predatory birds.
Sources and Credits
- (c) Amy Buthod, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/37738908@N00/395828737
- (c) Cullen Hanks, some rights reserved (CC BY-NC), uploaded by Cullen Hanks
- (c) Brenna Green, some rights reserved (CC BY-NC-ND), uploaded by Brenna Green
- Adapted by Desmon M Dunn from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Phrynosoma_cornutum
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Texas_horned_lizard
