Western Massasauga

Western Massasauga

Found in the United States in south eastern Nebraska, north western Missouri, east and central Kansas, west and central Oklahoma, northern and central Texas Southwest Iowa and northwest Missouri across Nebraska and western Oklahoma and southward across central Texas. There is an isolated disjunct population in southeastern Colorado.
Primarily found in grassland areas, on the edge of open woodland, or on rocky hillsides, and often makes use of the burrows of other animals for shelter.

The western massasauga (pronounced mass-a-saw'-ga) rattlesnake is one of the smallest rattlesnakes. Unlike its eastern relative, the western massasauga is lightly colored with dark brown blotches along its back or dorsal side that strongly contrast with the lightly colored soil and plants of the prairie. Its underbelly is light with some dark spots. The head has a series of nine large scales or plates on the top and there is a dark broad lateral stripe along each side.

It is a stout bodied snake with a triangular shaped head. There is a heat sensitive pit located between the eye and nostril. This pit is larger and positioned lower on the face than the nostril.

The massasauga has a rattle on the end of its tail. The rattle is comprised of a series of interlocking segments that make a buzzing noise when the tail is vibrated. The scales are keeled (have a dull, no-gloss surface) and the anal plate is single. The rattle’s small size makes it difficult to detect, often causing it to be confused with common water snakes

Western Massasauga
This snake is a relatively small and is considered a “calm”” snake. It rarely rattles, even when approached by potential predators; instead, it prefers to remain still and avoid being seen or heard. When it does rattle, the tail vibrations are very fast, involving twitches of 20-100 times per second, depending on the temperature (warm snakes rattle faster than cool ones). When rattling, the rattle gives off a high- pitched sound and has given the snake the nickname buzztail. If the warning fails, the snake will coil, rattle and strike quickly when confronted.

A pit viper, this snake has heat-sensitive pits on each side of its head, between the nostril and eye. These help the snake to find warm-blooded prey animals, especially at night. The venom of the massasauga rattlesnake is hemolytic, which means it breaks down red blood cells in its victim. Although it is highly toxic, very few humans have died from a massasauga bite.

To avoid detection by prey or predators its coloring provides the snake with camouflage that is perfect for hiding among long grass and other vegetation. Its camouflage combined with the way it moves makes it very difficult to spot. It is most active from April to October during the day, in the spring and fall. During the warm summer months it becomes more active at night. 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. Adults tend to use an ambush approach when hunting, holding still until the prey animal is about one third of its body length away. The strike happens very quickly and the fangs are sunk into the prey’s body. After injecting the venom, the snake often pulls away to avoid injury, waiting for the animal to die, swallowing them after the animal is dead.


During the spring males leave their hibernation sites and begin searching for food and mates. This may lead to an encounter with another male, resulting in combat. Generally the combat occurs only when a female is present. The males intertwine the anterior portions of their bodies while spiraling upward. The victor is determined by the male who forces his opponent to the ground. Often both snakes topple over and continue wrestling.

The winner of these matches usually mates with the nearby female. To court the female, the male actively tongue flicks the dorsal surface of the female's body. As the courtship ensues, the male's head begins to move to and fro in a jerky yet rhythmic motion. Eventually mating will occur. If his intentions are undesired, she will shove the male aside by using an arch of her coils.

Females are ovoviviparous, meaning they give birth to live young, rather than laying eggs externally. Young are born in late September to early October. The female gives birth to nine to 14 young measuring nine to 13.5 inches. The young snakes stay in their birth place for the first four to five days. They generally leave the area after they have shed their skin for the first time. The young are totally independent and the female provides no maternal care. They are typically born under a log, wood pile, or in abandoned mammal burrows.

In some populations, females only reproduce every other year. The average gestation period is between two to four months. By three years of age the young are sexually mature and are able to reproduce.

Interesting Facts:

The rattles are actually modified scales with a bony core. Each time the snake sheds its skin a new "button" is added to the rattle, therefore these rattles do not tell the snake's age, but the amount of times the animal has shed its skin. Massasaugas can shed their skin between 3 and 5 times a year, depending on their health and growth rate.

The western massasauga (pronounced mass-a-SAW-ga) rattlesnake gets its name from the Chippewa language. Massasauga means "great river mouth," which describes the snake’s habitat.


Presently their populations tend to be fragmented, and the species is considered in trouble in many areas across its range. The most serious threat to this snake species is habitat destruction.

Their survival is also threatened by humans who kill them on site because they are venomous. In some areas their den sites are destroyed intentionally. People will also travel long distances to collect snakes for “rattlesnake roundups” during which thousands can be killed. They are also popular in the pet trade and unfortunately fall victim to car tires as they bask on warm pavement.

The Western massasauga rattlesnake is now a candidate for federal listing under the United States Endangered Species Act. If the species is eventually listed as threatened or endangered, it will qualify for legal protection, including habitat protection.

Did YOU Know?    
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 lit
Western Massasauga
Class: reptiles
Order: Viperidae
Family: Sistrurus
Genus: Sistrurus
Species: catenatus tergeminus
Length: 13 to 36 inches, with 18 to 26 inches as the average length. Males are generally large than females.
Average Lifespan: In the wild the average lifespan is 14 years; longer in a zoological institution.
Wild Diet: Mainly rodents, but will also consume lizards, frogs, small birds and other snakes.
Zoo Diet: Rodents
Predators: Raccoons, hogs, skunks, foxes, hawks, and eagles.
USFWS Status: Considered endangered in many states.
Where at the Zoo? Small Animal Building

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