The western diamondback rattlesnake (Crotalus atrox) is a species of venomous rattlesnake found in the deserts of the United States of America and Mexico. The western diamondback rattlesnake is responsible for most of the snakebites in northern Mexico and the U.S.A. There are currently no subspecies found.

Description
Adult western diamondback rattlesnakes usually grow up to the length of 120 cm (3.9 ft), but some grow up to the length of 150 cm (4.9 ft) and 180 cm (5.9 ft). The longest ever found was 213 cm (6.99 ft) long. Males are much larger than females, but they become larger when they mature. These rattlesnakes usually weigh about 1.8 to 2.7 kg (4.0 to 6.0 Ib), but some can weigh 6.7 kg (15 Ib).They are usually gray-brown in color, but some are pinkish brown, or brick red. It is then covered with dark gray-brown blotches and white stripes.

Common names
The western diamondback rattlesnake is also known as the "adobe snake", the "Arizona diamond rattlesnake", the "coon-tail snake", the "desert diamondback snake", the "spitting rattlesnake", the "Texan snake", and the "Texas diamondback rattlesnake".

Where they live
In the U.S.A, the western diamondback rattlesnake is found in central and western Arkansas, Oklahoma, Texas, southern and central New Mexico, southern and central Arizona, southern Nevada, and southeastern California. In Mexico it is found in Nuevo Leòn, Coahuila, Chihuahua, Sonora, northeastern Baja California, northern Sinaloa, northeastern Durango, Zacatecas, San Luis Potosì, northern Veracruz, Hidalgo,and Querètaro. Some have been found on islands in the Gulf of California, like San Pedro Màtir, Santa Marìa, and Tìburon.

Habitat
The western diamondback rattlesnake is found in deserts, grasslands, pink-oak forests, coastal plains, and rocky canyons of the U.S.A and Mexico.

Behavior
Western diamondback rattlesnakes are one of the most aggressive rattlesnakes in North America, and usually coils and rattles when threatened.
In the winters they hibernate in caves and burrows with other snake species. They are very poor climbers.

Feeding
Around 94% of a western diamondback rattlesnake's diet is made up of small mammals like the prairie dog, the kangaroo rat, the pocket gopher, the vole, the wood rat, the pocket mouse, the white-footed mouse, the harvest mouse, the ground squirrel, the rabbit and moles. They also eat lizards and birds. Some of the birds they eat are the mockingbirds, burrowing owls, black-throated sparrows, and the eastern meadowlark. The lizards they eat are the whiptail liazards, spiny lizards, Texas banded gecko, and the side-blotched lizard. They also eat insects like the ant, beetle, and grasshopper. They usually hunt in the early morning or at night. 
The western diamondback rattlesnake is eaten by coyotes, foxes, and hawks.

Reproduction
The western diamondback rattlesnake is, like all rattlesnakes, viviparous. A female is pregnant for around six to seven mouths before giving birth to her young. The young only stay with their mother for a few hours before leaving on their own to go and hunt. They mate in spring and the female gives birth to around 12 to 25 young at a time. When they are born they are around 30 cm (12 in) long. Young western diamondback rattlesnakes have a venomous bite from the moment they are born. Western diamondback rattlesnakes live for around 20 years.

References

Vipers