more colorful than females. Morphological deviations between Cnemidophorus and Aspidoscelis refer to the fact that Aspidoscelis has (1) forked tongue structure posteriorly (2) no basal tongue sheath that lots of lizards have (3) smooth ventral scutes (enlarged scales in the belly) (4) eight rows of ventral scutes at midbody (5) no anal spurs in males (anal spurs are used by males to stimulate and position females during mating) (6) mesoptychial scales (scales in the gular/throat region of the lizard) abruptly enlarged (7) three parietal scales (enlarged scales on the crown, as often seen in snakes), and three or four supraocular scales (enlarged scales above the eyes) on each side. Like crocodiles, Western Mexico Whiptail have nictitating membrane eyelids, also called the third eyelids, which is a translucent membrane that, when the lizard blinks, is drawn from the inner corner of the eyes across the eyeball surface, while its upper and lower eyelids remain open. This allows moistening, protection of eye surface, and a certain degree of vision while blinking. Distribution and Habitat Most species of whiptail lizards prefer dry climates and seek out habitats in deserts. Therefore, many species of whiptail lizards are found throughout Sonoran Desert, spanning northwestern Mexico and southern California, a region with sparse vegetation, such as sagebrush, low desert scrubs, grasslands, woodlands and pine forests. Similarly, Aspidoscelis costatus prefers natural habitats such as savanna, and shrubland in brushy, broken country. But they also extend their habits into open areas of tropical low deciduous forest and thorn forest, low spiny sub-evergreen forest and medium sub-deciduous forest. spanning both temperate and tropical climates in western and southwestern Mexico. Since considerable habitat clearance has taken place for intensive agriculture or human settlements, we are starting to see urban population of Aspidoscelis costatus, even in densely populated cities, at least for Aspidoscelis costatus costatus, which is a subspecies of Western Mexico Whiptail lizard, commonly named Balsas Basin Whiptail. One research paper suggested that global warming has affected the habitats of Western Mexico Whiptail lizard. Some climatic groups of Aspidoscelis costatus costatus are exhibiting reductions and others exhibiting expansions in their distribution. Redistribution to higher elevation may potentially occur in response to climate warming. Ecology and Behavior Western Mexico whiptail are striped lizards, which tend to be active foragers, constantly moving around than lizards with cryptic patterns. It records very high moves per minute or percent time moving values. All whiptail