Phrynosoma cornutum

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. The horned lizard is popularly called a 'horned toad', or 'horned frog', but it is neither a toad nor a frog. The popular names come from the lizard's rounded body and blunt snout, which give it a decidedly batrachian appearance. Phrynosoma literally means 'toad-bodied' and cornutum means 'horned'. The lizard's horns are extensions of its cranium and contain true bone. 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). 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. About 70% of the Texas horned lizard's diet is made up of harvester ants, though they supplement these with termites, beetles, and grasshoppers. In recent years, the species has declined by about 30% of its range, though it may be making a comeback. The decline is usually blamed on overuse of pesticides and the spread of nonnative, highly aggressive and fiercely territorial red imported fire ants. Both eradicate harvester ant colonies, destroying the lizard's principal source of food. The Texas horned lizard is now a protected species, and, in Texas, it is illegal to take, possess, transport or sell them without a special permit. A University of Texas publication notes that horned lizard populations continue to disappear throughout the southwest despite protective legislation. The Texas horned lizard has disappeared from almost half of its geographic range. Population declines are attributed to loss of habitat, human eradication of the ant populations upon which the lizards prey, displacement of native ant populations by invading fire ants (aided by synergistic effects of native ant eradication), and predation by domestic dogs and cats. In 2014, the Center for Biological Diversity in Tucson, Arizona petitioned the Oklahoma Department of Wildlife Conservation to have the Texas horned lizard put on the endangered species list due to the massive declines of its population in Oklahoma, where it was once plentiful. The Center said it may later seek protection for the animal on a Federal level; it also said that reptiles in general are dying off at up to 10,000 times their historic extinction rate, greatly due to human influences. In Texas, the creature has been declared threatened and a breeding and reintroduction program has been started by the Fort Worth Zoo. Hatchlings are bred and released in targeted areas in the hope that with a large number of animals, enough will survive to grow the population in the wild. Typically in such reptile reintroduction programs, less than one percent of a female's offspring will survive in the wild to adulthood.