- Also called:
- western diamond-backed rattlesnake
- Related Topics:
- Crotalus
western diamondback rattlesnake
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What is a western diamondback rattlesnake?
The western diamondback rattlesnake (Crotalus atrox) is a venomous pit viper inhabiting North American scrublands from southern California to western Arkansas and northern Mexico. It is known for its aggressive nature and willingness to bite if threatened.
Western diamondbacks have a triangular head, stout body, and a tail with black and white rings. The body has diamond-shaped scale patterns. Adults average 4 to 6 feet in length, but can grow larger. They are active from spring through fall, preying on various animals, using heat-sensing pit organs to locate warm-blooded prey in the dark. Though they are preyed upon by birds of prey, foxes, and bobcats, they are also trampled by large mammals. Their bite can deliver venom that causes pain, swelling, necrosis, renal damage, and blood coagulation problems. About 10 to 20 percent of untreated bites are fatal.
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Where does the western diamondback rattlesnake live?
The western diamondback rattlesnake (Crotalus atrox) is a large, venomous pit viper. They live in arid and semiarid scrublands in North America, from southern California east to western Arkansas in the U.S., and south to northern Mexico. Their habitats include brushy flatlands, rock ledges, high river banks, and junk piles on the edges of towns and cities.
The International Union for Conservation of Nature and Natural Resources (IUCN) classifies the western diamondback rattlesnake as a species of least concern. They are common in their habitat, with a total adult population of over 100,000. However, they have been targeted by hunters in rattlesnake roundups, struck by vehicles, and some populations have been reduced by habitat loss.
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How does the western diamondback rattlesnake get its name?
The western diamondback rattlesnake gets its name from the dark, pale-bordered, diamond-shaped scale patterns along its body, which have a light center. Its base color often blends with the environment, ranging from dull gray to tan to reddish. Some living near deserts can be so pale that the markings are obscured except for the white borders of the diamond pattern.
The western diamondback rattlesnake (Crotalus atrox) is a large, venomous pit viper inhabiting arid and semiarid scrublands in North America, from southern California east to western Arkansas in the U.S., and south to northern Mexico.
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What does the western diamondback rattlesnake eat?
The western diamondback rattlesnake is active from early spring through late fall. It preys on a wide array of animals, including rabbits, rodents, ground birds, other reptiles, invertebrates, amphibians, and even fish. They prowl at night, using their pit organs to locate warm-blooded creatures in the dark.
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How does the western diamondback rattlesnake use its rattle?
The western diamondback rattlesnake uses its rattle as a warning device. The rattle is located at the tip of its tail and makes a buzzing sound when vibrated. When threatened, the snake may arch its head high, coil its body, and vibrate its rattle as a warning before striking.
The rattle itself is composed of loosely connected, hollow segments made of horn. A new segment is added each time the snake sheds its skin. Rattlesnakes can shed their skin multiple times a year; therefore, the number of segments cannot determine a snake's age.
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How does the venom of the western diamondback rattlesnake affect its prey or potential threats?
The western diamondback rattlesnake is known to be aggressive and readily bites if threatened. Rather than retreating, it defends itself by coiling, raising its head, vibrating its rattle, and striking before the warning sound is heeded.
Its venom, delivered in quantities up to 800 mg, causes pain, swelling, and necrosis at the bite site, and can also cause kidney damage and blood coagulation issues. Untreated bites have a 10 to 20 percent fatality rate.
The eastern diamondback rattlesnake uses its venom, which contains hemotoxin, to kill red blood cells and cause tissue damage. After striking, it tracks its prey via scent.
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western diamondback rattlesnake, (Crotalus atrox), a large, venomous, aggressive, and highly dangerous pit viper inhabiting arid and semiarid scrublands in North America from southern California east to western Arkansas in the U.S. and south to northern Mexico. Its typical habitats are brushy flatlands and slopes, rock ledges, high river banks, and junk piles on the edges of towns and cities. The western diamondback rattlesnake is classified in the subfamily Crotalinae, family Viperidae. Among rattlesnakes, it is second only to the eastern diamondback (C. adamanteus) in terms of size and fatalities delivered by its bite.
Natural history
The western diamondback is similar in appearance to its eastern counterpart. It has a triangular head, narrow neck, stout body, and short tail. Two diagonal stripes extend from each eye to the jaw. The body pattern consists of dark, pale-bordered, diamond-shaped scale patterning with a light center. The tail has a pattern of black and white rings. The base color of the snake often blends with that of its environment, from dull gray to tan to reddish. Some forms living near deserts can be so pale that the markings are obscured except for the white borders of the diamond pattern. Western diamondbacks can grow to more than 2.1 meters (about 7 feet) long, but most average between 1.2 and 1.8 meters (4 and 6 feet) in length. Although the largest individuals can weigh as much as 6.7 kg (14.7 pounds), most weigh between 1.4 and 2.7 kg (3 and 6 pounds).
The snake is active from early spring through late fall and preys on a wide variety of animals (including rabbits, rodents, ground birds, and other reptiles, along with invertebrates, amphibians, and even fish). It prowls at night for its prey, using its pit organs—sensory receptors that detect infrared radiation—to locate warm-blooded creatures in the dark. Western diamondbacks are food for birds of prey (such as eagles and hawks), foxes, and bobcats, but they are also trampled to death by larger mammals, such as deer and horses, who are threatened by the snake’s presence.
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Western diamondbacks hibernate through the winter, primarily in abandoned burrows of other animals, which they turn into communal dens; however, sometimes they can be found in burrows occupied by mammals, such as gophers and prairie dogs. Mating takes place before and after denning, the males engaging in ritual combat for access to females. Copulation may take hours to complete, and fertilized eggs are retained within the female’s body, where hatching also takes place before young are born alive. Litters average about a dozen young, who are left to fend for themselves after only a few hours. Young western diamondbacks become sexually mature at age 3. Although some individuals can live for more than 22 years in captivity, the life spans of western diamondbacks in the wild are thought to be about 20 years.
Snakebites
Western diamondback rattlesnakes are known for their aggressive nature and their willingness to bite those who threaten them. The snake is quick to defend itself when approached, and it holds its position instead of retreating. It may arch its head high, throw its body into a coil, vibrate its rattle, and strike before the warning sound can be heeded. Its bite can deliver as much as 800 mg (0.03 ounces) of venom to its victim, which can produce pain, swelling, and necrosis at the site of the bite and renal damage and problems with blood coagulation. Western diamondbacks bite hundreds of people throughout the southwestern United States and northern Mexico per year, and some 10 to 20 percent of untreated bites are fatal.
Conservation status
The western diamondback rattlesnake is classified as a species of least concern by the International Union for Conservation of Nature and Natural Resources (IUCN). It is common in its habitat, and population surveys strongly suggest that the total adult population numbers more than 100,000 and that the subpopulations that make up the species are stable. Because of their dangerous reputation, western diamondbacks have been targeted by hunters in “rattlesnake roundups.” Several individuals are also struck by vehicles each year, and there is evidence that some populations have been reduced by habitat loss.