Sistrurus species differ from the larger rattlesnakes of the genus Crotalus in a number of ways. They are smaller in size, but also their scalation is different: Sistrurus species have nine large head plates (same as Agkistrodon), whereas in Crotalus (and almost all other viperids), the head is mostly covered with a large number of smaller scales. Sistrurus species have a relatively small rattle that produces more of a high-pitched, buzzing sound than does a larger rattle, like that of Crotalus.
Although bites from Sistrurus species are regarded as less dangerous to humans than those from Crotalus rattlesnakes, primarily due to their lower venom yield, every venomous snake bite should be considered serious, and prompt medical treatment should always be sought.[citation needed]
Found throughout the Great Plains and southwestern states (from Kansas to Arizona) into disjunct populations in Mexico (Tamaulipas, southern Nuevo León, north-central Coahuila, and Samalayuca, Chihuahua). It inhabits grasslands, rocky hillsides, and woodland edges.
^Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates, a Division of Cornell University Press. (7th printing, 1985). 1,105 pp. (in two volumes). ISBN0-8014-0463-0. (Sistrurus, pp. 1040-1061).
Hubbs, Brian; O'Connor, Brendan (2012). A Guide to the Rattlesnakes and other Venomous Serpents of the United States. Tempe, Arizona: Tricolor Books. 129 pp. ISBN978-0-9754641-3-7. (Sistrurus, pp. 72–85).
Powell R, Conant R, Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 figures. ISBN978-0-544-12997-9. (Sistrurus, pp. 443–445).