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All About Eastern Massasauga Rattlesnakes

An eastern massasauga rattlesnake laying in brush.
Photo by Shaughn Galloway/USFWS.

Native to the Midwest, massasauga rattlesnakes (Sistrurus catenatus) are grayish brown with dark spots edged in white. They tend to be 18 to 30 inches long, have a blackish belly, and cat-like pupils on their wide, triangular head.

The temperament of the massasauga is generally considered non-aggressive. When feeling threatened, they remain motionless and rely on their ability to camouflage themselves from predators. When alarmed, the massasauga rattles their tail and creates a buzzing sound, like an alarmed bee, rather than the traditional rattlesnake sound.

Mating for the massasaugas occurs in the spring, summer and fall. They give birth to a litter of five to 20 young in August through early September.

Unlike some snake species that lay eggs, the massasauga gives birth live. Rattlesnakes are ovoviviparous, meaning the female carries the egg inside her body for about 3 months, and then she gives birth to live young.

The massasauga likes to live in a variety of wetland habitats, including wet prairies, marshes, wet meadows, and floodplain forests. Generally, they occupy the wetlands during the spring, fall and winter, yet in the summer they migrate to drier sites, like old forests and agricultural lands.

The massasaugas prey on small animals like shrews or mice. They can also consume other snake species, birds and frogs. Young massasaugas depend more on cold-blooded prey, like frogs. Although the massasaugas natural predators are hawks, skunks, raccoons, and foxes, they are commonly killed by humans. In 2016, the massasauga rattlesnake was listed as a threatened species due to habitat loss and human intervention.

Want to learn more about eastern massasauga rattlesnakes and other Cook County wildlife? Visit any of the Forest Preserves nature centers and talk to a naturalist!