The Western whiptail (Aspidoscelis tigris) is a species of lizard found in North America. It lives in a wide variety of habitats and has 16 recognized subspecies.
The Western whiptail has a long and slender body, small grainy scales on its back, and larger rectangular scales on its belly. The upper side often has light stripes, and the throat can be pinkish or somewhat orange in adults. Hatchlings of this species are orange-yellow with dark brown-black spots or stripes.
Western whiptails occur throughout northern Mexico and the western United States. In the US they can be found in the states of Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, and Utah. Western whiptails prefer to live in hot dry regions, typically with sparse foliage. They can be found in woodland, chaparral, riparian areas, or desert. Populations that live in the desert, prefer habitat with vegetation such as sagebrush or shadscale and use burrows in which they hide from the desert heat.
Western whiptails are solitary creatures and interact with each other only during the mating season. They usually hunt during the daylight hours and spend the night in the burrows which they dig themselves. In the morning they come out from their burrows to warm in the sun. If attacked by a predator, the Western whiptail will drop its tail to distract the predator. However, this is a last ditch effort because it is very stressful for the lizard. It takes a lot of energy to regrow the tail, and the lizard loses a lot of stored food. In the northern parts of their range, Western whiptails spend cold months hibernating under the ground. They usually emerge from hibernation in May, and most adults aestivate during the midsummer months, but in the south, Western whiptails are active from April through late August.
Western whiptails are carnivores (insectivores). They mostly eat insects, spiders, scorpions, lepidopterans, crickets, grasshoppers, and beetles.
Western whiptails are polygynous, meaning that during the breeding season, males mate with more than one female. In the northern parts of their range, Western whiptails mating breed in the first half of June, and females begin to lay eggs in late June. The eggs usually begin hatching by mid-August. Females will only lay one clutch per year. At the southern end of their range, however, females will begin to lay eggs as early as May, and the eggs will usually hatch as early as mid-June. In the southern parts, females may also lay two clutches per year instead of just one. A clutch usually contains up to 5 eggs and the incubation period lasts between 30 and 90 days. Baby whiptails are independent when they hatch and do not require parental care. Young females become reproductively mature at around 22 months of age, while males start to breed when they are 20 months old.
There are no major threats to this species at present.
The IUCN Red List and other sources don’t provide the number of the Western whiptail total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, and its numbers today are stable.
