University of Massachusetts Amherst

Snake of Massachusetts

Snakes of Massachusetts

Timber Rattlesnake

Crotalus horridus (36-60", up to 74")
MA Status: "Endangered." Illegal to harass, kill, collect or possess.

A robust, venomous snake, the timber rattler is equipped with a broad triangular head, vertical pupils and heat sensitive pits. The body color may be yellow, gray, dark brown or black, with dark, V-shaped crossbands across the back. The pattern may not be obvious if the body is very dark. The head is usually unpatterned and is covered with many small scales. A distinct rattle on the end of a darkly colored tail produces a buzzing sound when vibrated. When young, the rattlesnake has only a small button on the tail. Body scales are strongly keeled and the light colored belly is flecked with dark spots.

Mating usually occurs in summer or fall. Females incubate eggs within their bodies by basking, and give birth the following year to 6-10 young from mid-August through September. Female rattlesnakes typically give birth every two or three years.

Although rocky forested hill-sides with southern exposures are essential as winter habitat, rattlesnakes prefer dense forests with a thick understory for foraging. They bask during the day and forage at night, when prey is most abundant. Rattlesnakes prey on a variety of warm-blooded animals, including: mice, chipmunks and other squirrels, rabbits, shrews, moles, weasels and birds. Occasionally, rattlesnakes will also feed on insects, amphibians and other snakes. When threatened, they vibrate their tails to produce a loud buzzing sound that is difficult to miss. They are not particularly aggressive and bites are rare. In Massachusetts, rattlesnakes are so rare that they are almost never encountered by people.

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