Crotalus atrox, more commonly referred to as western diamondback rattlesnakes, are called the largest rattlesnakes in North America. They measure anywhere from 3 to 7 feet (0.9 to 2.1 meters) long, but only weigh 1 to 2 pounds (0.4 to 0.9 kilograms). Their famous rattles are made up of keratin (the same material found in fingernails) and a new segment is added every time they shed. Despite this, it is not possible to determine their age by the number of segments on their rattles as all snakes shed differently, not to mention the fact that segments will fall off at times.
Western diamondback rattlesnakes are found throughout the southwestern United States as well as the northern half of Mexico. They live in a variety of habitats including desert flats, rocky hillsides, forested areas, grassy plains, river bottoms and coastal prairies. They can even be located up to 7,000 feet (2,132 meters) above sea level. Western diamondback rattlesnakes are active mostly at night and spend the day in cooling off under the shade of a rock or shrub. They will sometimes even use the underground burrow of another animal should they feel like it. When winter comes along, they will gather in a community den called as hibernacula (often located in a dark cave or something similar) in order to hibernate.
Western diamondback rattlesnakes eat a variety of creatures such as birds, lizards, rabbits, gophers, and other small mammals. Being pit vipers, they have heat-seeking pits between their nostrils and their eyes which they use to detect temperature changes as low as a fraction of a degree. They use this information to separate prey from predator. Once prey has been found, they will bite and invenomate their catch. Once their food is incapacitated, they will proceed to swallow it whole and digest it as it moves through their body. This process allows them to only have to eat every 2 to 3 weeks. Sometimes, their fangs will break off and remain in their prey, but will quickly be replaced by a reserve set of fangs (they can do this up to 5 times a year).
Mating season for western diamondback rattlesnakes takes place in the spring, after they emerge from hibernation. The gestation period for females is about 167 days and they give birth to 10 to 20 live young (they hatch right before they are born). Young rattlesnakes are fully developed at birth and will stay with their mother anywhere from 2 hours to up to a day before they are abandoned. If they manage to survive, they can live up to 20 years.
Western diamondback rattlesnakes are the cause of numerous snake bites. It is best to get help immediately after being bitten by one. Confrontations can be avoided however, if you are mindful of your surroundings and listen for their famous rattling sound. If confrontations are kept to a minimal, there is no reason why these snakes cannot survive well into the future.
Works Cited
“Animal Fact Sheet: Western Diamondback Rattlesnake” 22 November 2010
