Massasauga

## Description

The massasauga (Sistrurus catenatus ) is a rattlesnake species found in midwestern North America from southern Ontario to northern Mexico and parts of the United States in between. Like all rattlesnakes, it is a pit viper, and like all pit vipers, it is venomous.

Three subspecies were recognized for more than a century, although research published in 2011 elevated two subspecies Sistrurus catenatus catenatus and Sistrurus catenatus tergeminus, to full species: the eastern massasauga (Sistrurus catenatus ) and the western massasauga (Sistrurus tergeminus ). The status of the third subspecies was somewhat unresolved and it is tentatively recognized as the desert massasauga (Sistrurus tergeminus edwardsii ) by some, or synonymized with the western massasauga (Sistrurus tergeminus ) by others.

## Appearance

The Massasauga is a venomous rattlesnake species found in midwestern North America. Like all rattlesnakes, it belongs to the pit viper family. Massasaugas are grey or tan in color with a row of large rounded brown/black blotches or spots down the center of the back and three smaller rows of alternating spots down each side. Solid black melanistic examples are also known, as well as cases where the back blotches join with those on the sides. Young massasaugas are well-patterned but paler than the adults. These snakes have heat-sensing pits on each side of their smallish head and their scales are keeled.

## Distribution

Massasaugas are found in North America from Ontario, Canada, and western New York southwest to southeastern Arizona in the United States and northern Tamaulipas, Mexico. In Mexico, isolated populations exist in southern Nuevo León, north-central Coahuila, and Samalayuca, Chihuahua. These rattlesnakes live in various habitats ranging from swamps, bogs, sedge meadows, wet prairies and marshes to grasslands and forests. In the western part of their range, Massasaugas can be found in rocky hillsides, wetlands, scrub plains, desert grassland, and dry prairie.

## Behavior

Massasaugas are diurnal and lead a solitary life. During hot summer months, they are usually active early morning and late evening trying to avoid the heat of the day. Massasaugas stay active from April till late October and hibernate during winter in small abandoned burrows of other small animals. These rattlesnakes are very good swimmers and can even hunt their prey in the water. They detect prey with the sense of smell and with the help of heat-sensitive pits located on their faces. They can also feel vibrations and have good eyesight. When threatened, Massasaugas will warn or show aggression rattling their tail, coiling up and unexpected striking.

## Venom

The venom of S. c. catenatus is a cytotoxic venom, so destroys tissue. It also contains specialized digestive enzymes that disrupt blood flow and prevent blood clotting. Severe internal bleeding causes the death of the small animals that this snake eats. After envenomation, the rattlesnake is able to withdraw from the dangers of sharp-toothed prey animals until they are subdued and even partially digested by the action of the venom.

S. c. catenatus is rather shy and avoids humans when it can. Most massasauga snakebites in Ontario have occurred after people deliberately handled or accidentally stepped on one of these animals. Both of these scenarios can be prevented by avoiding hiking through areas of low visibility (in rattlesnake country) when not wearing shoes and long pants and by leaving the snakes alone if encountered. Only two incidents of people dying from massasauga rattlesnake bites in Ontario have been recorded; in both cases, the victims did not receive proper treatment.

## Diet

Massasaugas are carnivores; they feed on small vertebrates, including mammals, lizards, and other snakes, as well as invertebrates such as centipedes. Adults feed mainly on rodents, while juveniles usually prey on reptiles: more often lizards in western populations and snakes in eastern ones.

## Reproduction

The breeding season for Massasaugas begins in the spring and can also occur in the fall. When females are ready to mate they shed their old skin and release pheromones that attract males. Females give birth to 5-20 live young usually in abandoned mammal burrows or fallen logs. The gestation period lasts around 3.5 months. Snakelets are born fully-developed and stay around their mother for a few days; after that, they disperse. Young Massasaugas become reproductively mature and ready to mate at 3 to 4 years of age.

## Population

### Population threats

The biggest threat facing Massasaugas is habitat loss. Historically, this has been due to human activity, and more recently primarily from natural forest succession. These snakes are also heavily persecuted because they are considered to be a threat due to their venomous and lethal bite.

### Population number

The IUCN Red List and other sources don’t provide the number of the Massasauga total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.

### Ecological niche

Massasaugas play a very important role in their ecosystem. Due to their diet habits, these snakes control populations of rodents and other small mammals as well as help control pests in agricultural fields.

## Fun Facts

Other common names of these snakes include dwarf prairie rattlesnake, eastern massasauga great adder, ground rattlesnake, Kirtland's rattlesnake, little black rattlesnake, Michigan point rattler (Michigan), prairie massasauga, rattlesnake, small prairie rattlesnake, snapper, swamp massasauga, swamp rattlesnake, and triple-spotted rattlesnake.

The Native American word, "massasauga", means "great river-mouth" in the Ojibwe language and was probably given to describe grasslands surrounding the river deltas in Ojibwe country.