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. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

found in the

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

region of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

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, in San Diego), was an American herpetologist and the foremost authority on rattlesnakes. He was the first curator of reptiles and amphibians at the San Diego Nat ...

in 1930 as a subspecies of ''Crotalus confluentus'' (now known as '' Crotalus viridis''). It is commonly considered a subspecies of ''

Crotalus oreganus ''Crotalus oreganus'', commonly known as the Western rattlesnake or northern Pacific rattlesnake,Albert Hazen WWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. . is a venomous snake, ...

''. 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 2020 United States census, the population was 12,975. Its county seat is Fillmore, and the largest city is Delta. History The Utah Territory legislature created the county ...

." 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. (7 ...

– 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 landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

south of lat. 44° North,

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

west of long. 111° West,

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

west and north of the

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

as well as the north rim of the

Grand Canyon The Grand Canyon 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 mile (). The canyon and adjacent rim are contained within Grand Canyon Nati ...

, the entire state of

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

(excluding Esmeralda, Nye and Clark counties),

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

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 primari ...

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 United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

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, 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, stra ...

–

Burns Burns may refer to: Astronomy * 2708 Burns, an asteroid * Burns (crater), on Mercury People * Burns (surname), list of people and characters named Burns ** Burns (musician), Scottish record producer Places in the United States * Burns, ...

–

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 ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

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 ...

s, and

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

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 Endemic reptiles of the United States Fauna of the Great Basin Reptiles described in 1930