The Great Basin rattlesnake (''Crotalus lutosus'') is a

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

found in the

Great Basin The Great Basin is the largest area of contiguous endorheic basin, endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California ...

region of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

Taxonomy and naming

The Great basin rattlesnake was first formally named by

Laurence Monroe Klauber Laurence Monroe Klauber (December 21, 1883 in San Diego, California – May 8, 1968), was an American herpetology, herpetologist and the foremost authority on rattlesnakes. He was the first curator of reptiles and amphibians at the San Diego Natural ...

in 1930 as a subspecies of ''Crotalus confluentus'' (now known as ''

Crotalus viridis ''Crotalus viridis'' (Common names: prairie rattlesnake, Great Plains rattlesnake, Wright AH, Wright AA. 1957. ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. (7th printing, 1985). 1,105 ...

''). It is commonly considered a subspecies of ''

Crotalus oreganus ''Crotalus oreganus'', commonly known as the (northern) Pacific rattlesnake, Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. . is a venomous pit viper species found in western North A ...

''. The type locality is "10 miles northwest of Abraham on the Road to Joy,

Millard County, Utah Millard County ( ) is a county in the U.S. state of Utah. As of the 2010 United States Census, the population was 12,503. Its county seat is Fillmore, and the largest city is Delta. History The Utah Territory legislature created the county on ...

." The Grand Canyon rattlesnake (''C. abyssus'' or ''C. oreganus abyssus'') was subsumed within ''C. lutosus'' in 2016.

Description

Adult specimens are in overall length, but rarely exceed .Campbell JA, Lamar WW. 2004. ''The Venomous Reptiles of the Western Hemisphere''. Comstock Publishing Associates, Ithaca and London. 870 pp., 1500 plates. . The males grow larger than the females. On the subject of scalation, one of the more distinctive characteristics of this subspecies is that it has three or more

internasal scales In snakes, the internasal scales are those on top of the head between the scales that surround the nostrils. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. (7t ...

– something that it has in common with '' C. viridis''. The color pattern usually consists of a buff, pale gray, pale brown, olive brown or yellowish brown ground color (hence the name, "lutosus," meaning "muddy"), overlaid with a series of 32-49 dorsal blotches. These blotches are dark brown to black in color, with pale centers and pale borders, and are often irregular in shape and wider than they are long. There is also a series of lateral blotches that are indistinct anteriorly, but become more distinct posteriorly and eventually merge with the dorsal blotches to form crossbands. Older specimens sometimes have a faded pattern, or they may have uniformly black blotches, with the dorsum of the head also being black.

Distribution and habitat

The

in the

region. Its range includes

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

south of lat. 44° North,

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

west of long. 111° West,

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

west and north of the

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid drainage basin, watershed that encompasses parts of ...

as well as the north rim of the

Grand Canyon The Grand Canyon (, yuf-x-yav, Wi:kaʼi:la, , Southern Paiute language: Paxa’uipi, ) is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a m ...

, the entire state of

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

(excluding Esmeralda, Nye and

Clark Clark is an English language surname, ultimately derived from the Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone who was educate ...

counties),

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

east of the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

from

Lower Klamath Lake Lower Klamath Lake is a lake in Siskiyou County, California. At one time it was connected to Upper Klamath Lake. It currently is used to hold overflow water for Klamath Project irrigation uses. The lake is in Northern California, near the borde ...

south to below Lake Mono,

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

south and east of the line

Upper Klamath Lake Upper Klamath Lake (sometimes called Klamath Lake) ( Klamath: ?ews, "lake" ) is a large, shallow freshwater lake east of the Cascade Range in south-central Oregon in the United States. The largest body of fresh water by surface area in Oregon, it ...

–

Fort Rock Fort Rock is a tuff ring located on an ice age lake bed in north Lake County, Oregon, United States. The ring is about in diameter and stands about high above the surrounding plain. Its name is derived from the tall, straight sides that resem ...

–

Burns Burns may refer to: * Burn, an injury (plural) People: * Burns (surname), includes list of people and characters Business: * Burns London, a British guitar maker Places: ;In the United States * Burns, Colorado, unincorporated community in Eagle ...

–

Council A council is a group of people who come together to consult, deliberate, or make decisions. A council may function as a legislature, especially at a town, city or county/shire level, but most legislative bodies at the state/provincial or natio ...

(

). Klauber LM. 1997. ''Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition''. First published in 1956, 1972. University of California Press, Berkeley. . Inhabits the dry and barren areas of the

region, being found on hills, summits and old lake benches. They are said to prefer southern exposures among rocks and boulders on hillsides and buttes, low foothills, mountainsides, open deserts, alfalfa fields and valley floors. They are most commonly seen by humans while hiking ''Great Basin Rattlesnakes in Bryce Canyon''. but also on the side of the road at night looking for prey.

Diet

''Crotalus lutosus'' feeds on

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s, bird

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s, and

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s.Hubbs, Brian, and Brendan O'Connor. 2012. ''A Guide to the Rattlesnakes and other Venomous Serpents of the United States''. Tricolor Books. Tempe, Arizona. 129 pp. (''Crotalus oreganus lutosus'', pp. 28-29.)

Reproduction

Young are born alive in broods of 3 to 13.

Conservation status

The Great Basin rattlesnake is protected in

References

{{Taxonbar, from=Q5188961 lutosus Snakes of North America Reptiles of the United States Endemic fauna of the United States Fauna of the Great Basin Reptiles described in 1930