Rattle Snake Identification

Rattlesnakes are common in the southwestern U.S.

Rattlesnakes are a type of viper. About 30 different species inhabit the Western Hemisphere. Such a diverse group of snakes is sometimes difficult to identify, but they all share a number of features.

Habitat

Along with the moccasins, rattlesnakes are the only vipers in the United States. They live in grasslands, scrub brush, rocky hills and deserts from the northern United States to the tip of South America. Rattlesnakes are found most often in the deserts of the southwestern United States and Mexico.

Rattle

The most distinctive feature of a rattlesnake is its rattle, which is a sound made when the modified hollow scales on the end of its tail rub together. It is used to warn off encroaching animals. The Arizona-Sonora Desert Museum states that newborn rattlesnakes have a segment called a pre-button that is lost the first time its skin is shed. A new segment is added upon every subsequent shedding, which may happen one to four times a year.

Size and Shape

According to the San Diego Zoo, the length of a rattlesnake can vary dramatically. The smallest is the ridge-nosed rattlesnake, which grows to about a foot in length. The longest, the eastern diamondback, is about 8 feet long. The average adult rattlesnake is about 2 to 4 feet long. A rattlesnake's head resembles the shape of a heart.

Young Rattlesnakes

Young rattlesnakes are about 7 to 15 inches long at birth and reach maturity in 18 to 24 months. Unlike most other reptiles, which hatch from eggs when outside the mother, a viper's young are born live. Baby rattlesnakes have full use of venom from birth and are usually much more aggressive than mature snakes.

Color and Markings

Most rattlesnake species are brown and yellow, which helps them blend with desert surroundings, but some have white or black markings. The sidewinder, for example, is white and light brown, while the timber rattlesnake is black and dark brown. These colors tend to alternate, and the darker color usually appears as spots.

References

• San Diego Zoo: Rattlesnake
• Arizona-Sonora Desert Museum: Rattlesnakes