:Common names: Grand Canyon rattlesnake, canyon bleached rattlesnake. ''Crotalus oreganus abyssus'' 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 ...

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

found only in the

U.S. states In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

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 ...

and

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 ...

Description

This is a medium to large rattlesnake. Adults measure in total length. Dorsally, they have dark blotches on a variety of base colors ranging from reddish, pink, yellow/green, light tan, to gray. The blotches usually become crossbands near the tail. The young usually have more prominent blotches and facial markings than the adults. Some adults have no body markings. The

rostral scale The rostral scale, or rostral, in snakes and other scaled reptiles is the median plate on the tip of the snout that borders the mouth opening. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: ...

usually comes into contact with more than 2 internasal scales. Grand_Canyon_rattlesnake

Geographic range

Found in northwestern and north-central

along both rims and the floor of the Grand Canyon and adjacent areas,, and North into Utah on the Kaiparowits Plateau between the Escalante River and Paria River Drainages of Kane and Garfield Counties, Utah.

Habitat

The snake is found in a variety of habitats, including grassland,

Great Basin Desert The Great Basin Desert is part of the Great Basin between the Sierra Nevada and the Wasatch Range in the western United States. The desert is a geographical region that largely overlaps the Great Basin shrub steppe defined by the World Wildlife ...

scrubland, bottoms in 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 ...

, talus and cliff slopes, rolling hills and bajadas in pinion-juniper woodland, and

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

forests.

Behavior

It is primarily diurnal but can be active around the clock when conditions are favorable. The cryptic coloration and calm demeanor of this subspecies often allows it to escape detection from passers-by.

Feeding

It feeds on mice, lizards, and birds. Like other pit vipers, the Grand Canyon Rattlesnake has heat-sensitive pits that identify body heat of animals to help with hunting. Rock squirrels, which are common in the Grand Canyon area, evade the snake through a process called "mobbing," where the squirrel will attack the snake by kicking dirt and rocks and rapidly waving their tails to heat the air around them, causing the snake to believe there is a larger mammal coming to attack.

Taxonomy notes

Some researchers list this taxon as elevated to a full species as (''Crotalus abyssus''), or as a subspecies of the Great Basin Rattlesnake ('' Crotalus lutosus'') as ''Crotalus lutosus abyssus'', in the Annotated Checklist of the Rattlesnakes (Second Edition), published in The Biology of Rattlesnakes II 2017.

References

External links

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Images of ''Crotalus oreganus abyssus''
a
California Reptiles and Amphibians
Accessed 18 June 2008. {{Authority control oreganus abyssus Endemic reptiles of the United States Fauna of the Southwestern United States Natural history of the Grand Canyon