Common names: Hopi rattlesnake, Arizona prairie rattlesnake, prairie rattlesnake. Crotalus viridis nuntius is a venomous pit viper subspecies native primarily to the desert plateau of the northeastern portion of the American state of Arizona, but also ranges into northwestern New Mexico. Named for the Native American Hopi tribe, which inhabits the region, its range overlaps that of the nominate subspecies and some interbreeding is believed to occur. The taxonomy of the C. viridis group is a matter of debate, many considering the various subspecies to be nothing more than locality variations. Description Smaller than other subspecies of C. viridis, this subspecies generally does not generally grow much beyond two feet in length. They are typically pink, to gray, to orange-brown in color, reflecting the color of the soil and rocks of their natural range for camouflage, with darker brown blotching down the back. The scalation consists of 21-27 (usually 25) midbody dorsal scales, 169-184 ventral scales in females and 162-178 in males, 14-22 subcaudal scales in females and 21-28 in males. The color pattern includes 33-53 dorsal body blotches. According to Douglas et al. (2002), it is not possible to reliably distinguish C. v. nuntius from C. v. viridis. Like other rattlesnakes, they have eyes with vertical pupils, and their tail has a rattle on it. The rattle is composed of keratin. Each time the snake sheds its skin, a new segment is added to the rattle, but the rattle is fragile and may break off, and the frequency of shedding can vary, so the snake's age cannot be determined by its length or number of segments. Geographic range Found in northeast Arizona (United States) at elevations of 1372–2134 m. The type locality is listed as "Canyon Diablo, Coconino County, Arizona" (USA). Behavior These are generally nocturnal and secretive snakes, spending their days in rock crevices or other animal's burrows to avoid the desert heat, emerging in the early day to feed on rodents, birds, lizards, and sometimes frogs. While not typically aggressive, they will often coil up and rattle their tail if disturbed, striking only if harassed or handled. Their venom is primarily hemotoxic, causing swelling and necrosis, but many populations of C. viridis are known to have a potent neurotoxic effect as well, resulting in muscle paralysis and possibly respiratory failure. They are capable of delivering what is known as a "dry bite", in which no venom is