Tiger Rattlesnake

The tiger rattlesnake is easily identified by its small, spade-shaped head, which is about 1/25 of its total body length. It has the smallest head of any rattlesnake, and a large rattle. The color pattern consists of a gray, lavender, blue-gray, pink, or buff ground color that usually turns to pink, pale orange, or cream on the sides. Tiger rattlesnakes are the only rattlesnake with crossbands on the anterior portion of their bodies, with a series of 35 to 52 gray, olive, or brown bands across the dorsum consisting mainly of heavy punctations. These crossbands have vague borders and are wider dorsally than laterally. Also mid-dorsally, the crossbands become wider than the spaces that separate them. Posteriorly, the crossbands become darker and more clearly defined. They have six to 10 posterior rings. The markings on the head are mostly vague and irregular, although towards the rear of the head, a few dark markings may be arranged as paired occipital blotches and upper temporal streaks. The most distinguishable mark on the head is a dark cheek strip. Dorsal scales are keeled and in 21 to 27 rows. A relatively small species, individuals can weigh as much as 454 g (16.0 oz) and can range in length from 460 to 910 mm (18 to 36 in), with an average length of 609 mm (24.0 in). The largest specimen on record measured 88.5 cm (34.8 in) (Klauber, 1956), until H.M. …

The species' range extends from central Arizona south through south-central Arizona in the United States, to southern Sonora, Mexico, including Isla Tiburón in the Gulf of California and was recently discovered in the southern Peloncillo Mountains of Arizona. The type locality is described as "Sierra Verde and Pozo Verde". The latter is a spring located on the Sonora side of the US-Mexico border, near Sasabe. According to Stejneger (1893), this spring is on the western slope of the southern Sierra Verde, which is also known as the Sierra del Pozo Verde. In these areas, the tiger rattlesnake is observed at elevations from sea level to about 1,465 m (4,806 ft) Reported occurrences at higher elevations have not been confirmed. Tiger rattlesnakes habitats include rocky desert canyons, foothills, and bajadas, in vegetation zones ranging from thornscrub, ocotillo-mesquite-creosote bush, saguaro-paloverde, mesquite grassland, and chaparral to tropical deciduous forest (southern Sonora) and the lower edge of oak woodland. In southeastern Arizona, this snake occurs strictly in rocky areas in winter and spring, but uses edges of arroyos in summer. …

Tiger rattlesnakes are terrestrial snakes and are nocturnal during the hot summer (June–August), but become diurnal and crepuscular during the fall season. They hibernate during the late fall and winter in rock crevices or animal burrows. In spite of being ground-dwelling, their activity is not restricted to the ground. They swim readily and have been found in bushes 60 cm (24 in) above the ground. Little information is available concerning communication and perception among tiger rattlesnakes. However, like other pit vipers, tiger rattlesnakes have heat-sensing pits (located on each side of the face between the eye and nostril) to detect warm-blooded predators and prey. This snake is inactive in cold temperatures (December/January) and extreme heat (July/August). It may be active both day and night; daytime activity consists mainly of basking on cool days. These snakes are often observed being active after warm rains. In southeastern Arizona, they are active mainly from March to October.