Visitor & Tickets
Animals & Exhibits
Learning Adventures
The grizzly’s thick coat ranges in color from off-white, tan, yellow, and brown to black. read more >

Western massasauga

Scientific name: Sistrurus catenatus tergeminus

CLASS: Reptilia

Length: 7 to 45 in.

Unlike its eastern relative, the western massasauga is lightly colored with dark brown blotches along the edges that strongly contrast with the lightly colored ground cover of the prairie. This snake’s underbelly is light with some dark spots. There are about 25 rows of scales around the midbody.

The massasauga has a rattle on the end of its tail, but the small size of this rattle makes it difficult to detect and therefore the massasauga is easily confused with common water snakes. Its rattle, which does not rise as high as in other rattlesnakes, is a warning sign telling predators this snake is venomous. Every time the snake sheds its skin, which is about four times a year, the rattle grows a segment.

Central United States to the Gulf of Mexico

Western United States, living on the plains and prairies and desert grasslands, utilizing marshy areas and rocky outcrops.

The massasauga is active from April to October. It is diurnal in the spring and fall but may be more active at night, or nocturnal, during the summer months. It is known to lie in the sun waiting for prey. In the winter, it lives deep in rock crevices or in rodent burrows. This snake is sluggish and mild mannered.

The massasauga usually finds endothermic, or warm-blooded, prey by the heat sensory facial pits located just above its mouth, but it also uses sight and smell to locate prey. Young massasaugas may use tail luring, moving their tails in such a way as to attract a frog or a lizard. Once the prey is close enough the snake attacks.

The massasauga has short fangs for a rattlesnake, only 4.5-5.9 mm in length. The average adult massasauga carries 31 mg of venom, and only releases 5-6 mg per bite. It only takes about 4.4 mg of venom to kill a mouse, while the projected human lethal dose is 30-40 mg. Symptoms of bites include pain, discoloration, and swelling. A cold sweat, faintness, nausea, tremors, and nervousness might also occur.

Female massasaugas become sexually mature at three or four years of age, but most do not reproduce until at least five to seven years of age. The massasaugas’ mating season occurs from mid-July to mid-September, but the snakes do not ovulate and the eggs are not fertilized until the following spring. The offspring are born live and fully developed. The brood size is anywhere from two to 19.

Prey to hawks, owls, cranes, and some mammals
Predator to small rodents, frogs, and other snakes

Small rodents, frogs, other small snakes, and lizards

Not listed by IUCN, but it is considered endangered in many states.


  • The venom of the massasauga rattlesnake is hemolytic, which means it breaks down red blood cells causing its victim to die from lack of oxygen. Even though this snake’s venom is incredibly dangerous, very few people actually die from a bite since little venom is administered during a bite.


  1. Conant, Robert, & J. T. Collins. Reptiles and Amphibians Eastern/Central North America. Boston, New York: Houghton Mifflin Company, 1991.
  2. Ernst, C. H. Venomous Reptiles of North America. Washington and London: Smithsonian Institution’s Press, 1992, p.72-74
  3. Collins, J.T. A Guide to Great Snakes of Kansas. Western Resources, Topeka Kansas. 1998

Published: April 2009

Want to learn more about animals?

Check out our Learning Adventures for newborn to 99.

Early Childhood
Middle / High School
Senior Citizens

Hours of Operation
Summer8:30 a.m. to 5:00 p.m.
(March – October)
Winter10:00 a.m. to 5:00 p.m.
(November – February)
*The Zoo will be closed one day only, September 8, 2018 to facilitate the preparation of the annual Zoo fundraiser, Zoobilee.