Crotalus is a genus of pit vipers, commonly known as rattlesnakes or rattlers, in the family Viperidae. The genus is found only in the Americas from southern Canada to northern Argentina. As of July 2023, 44 to 53 species are recognized as valid.
Description
Members of the genus Crotalus range in size from only (C. intermedius, C. pricei), to over (eastern and western diamondback rattlesnakes). Most forms are easily recognized by the characteristic rattle on the end of their tails, although a few island populations form exceptions to this rule: C. catalinensis has lost its rattle entirely, Crotalus lorenzoensis usually has no rattle, and both Crotalus ruber lucasensis and Crotalus estebanensis exhibit a tendency for rattle loss. The rattle may also be lacking in any species due to a congenital abnormality.
Distribution and habitat
The genus Crotalus is found in the Americas from southern Canada to central Argentina.
Behavior
No species of Crotalus is considered aggressive; when threatened, most retreat quickly, but most species defend themselves readily when cornered. while those less frequently taken include birds, snakes, and amphibians. Cannibalism has been reported in a number of different species. Individuals that feed on rodents usually release their prey after a strike to avoid their teeth, and these snakes evidently can discriminate between trails left by prey that has or has not been envenomated. Certain species of birds frequently prey on these snakes, but this is not without risk. Two cases were reported in which dead hawks found near venomous snakes had suffered hemorrhage and gangrenous necrosis due to snakebite. mate the following spring, and give birth later in September or October. Second, the platelet antagonist crotalin creates a severe bleeding effect as it binds to the surface proteins, blocking aggregation.
Neurotoxic effects may also be caused by rattlesnake venom. These effects vary by species, and within species by population.
Species
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!bgcolor="#f0f0f0"|Species
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|C. unicolor
|Klauber, 1936
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|Aruba rattlesnake
|Aruba
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|C. vegrandis
|Klauber, 1941
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|Uracoan rattlesnake
|style="width:35%"| Eastern Venezuela
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|C. viridis
|(Rafinesque, 1818)
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|Prairie rattlesnake
|Southern Canada (Alberta, Saskatchewan), south through the US (eastern Idaho, Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, Texas, New Mexico, extreme eastern Arizona), and into northern Mexico (northern Coahuila, northwestern Chihuahua)