Eastern Massasauga - Sistrurus catenatus
The
Eastern massasauga is a small, timid rattlesnake that lives in the big
river floodplains of north Missouri. It is found primarily in wet prairies,
marshes and meadows. Missouri has lost 87% of its wetlands since 1900,
to the detriment of the Eastern massasauga and many other wetland species.
The massasauga is also threatened by indiscriminate killing. It is listed ENDANGERED by
the Missouri Department of Conservation and a candidate for federal listing
by the U.S. Fish and Wildlife Service.
Identification
The
Eastern massasauga is one of Missouri's three native rattlesnake species.
It has a short, thick body that averages 20 to 30 inches long. The body
is gray to gray-brown, with dark brown blotches down the middle of its
back and along both sides of its body. The head is a thick diamond shape
with dark stripes extending back from the eyes. Massasaugas' tails end
in a stubby rattle; juveniles' tails are yellowish. Like other venomous
snakes, massasaugas have sensory pits on the sides of their heads, and
the pupils of their eyes are diamond-shaped instead of round.
The only other rattlesnake found in northern missouri is the timber rattlesnake, which grows much larger (36 to 54 inches) and has a distinct rust-colored stripe down its back. Other similar, but non-venomous, snakes can be distinguished from the massasauga by their round pupils, lack of sensory pits, and rattle-less tails.
For a technical description of this animal, refer to:
Johnson, T.R. 1987. The Amphibians and Reptiles of Missouri. Missouri Department of Conservation. Jefferson City, Missouri. 368 pp.
Habitat and Distribution
Eastern
massasuagas are primarily found in bottomland or wet prairies dominated
by cordgrass, sedges, bullrushes, and smartweeds, and lowlands along rivers,
lakes, and marshes. They also occupy prairie-forest transition zones. The
Eastern massasauga overwinters in moist lowland areas, taking shelter in
the burrows of crayfish and other animals. Massasaugas emerge from overwinter
dormancy during mid-April. During the summer, massasaguas live along the
edge of wet prairies and feed on voles. In early October, massasaugas migrate
back to overwintering areas, in some cases traveling distances of over
1 1/2 miles.
The Eastern massasauga is primarily active during the day, except during the hottest part of summer when it becomes more active at night. Female massasaugas are believed to reproduce every other year. Mating occurs in late summer, and females give birth to an average of 4 to 10 live young. The massasagua feeds primarily upon rodents and small snakes.
The former range of the Eastern massasauga includes floodplain wetlands of the Mississippi River, Missouri River, and Grand River of northern Missouri. There are historical records of massasaugas from 10 Missouri counties, but the snake has recently been recorded in only Chariton Linn , and Holt counties.
Cause of Historic Decline
Massasaugas require wetland habitats associated with river floodplains of north Missouri. Declines in populations have resulted from the loss of habitat as floodplains were converted to agricultural land. Massasaugas tolerate some agricultural development, but they need a mixture of habitat types to reproduce and safely overwinter. Human persecution has also added to the decline. Many massasaugas are found on refuges which provide protection and a diversity of habitats. Individuals and landowners can take an active role in protecting and encouraging this species.
Current Threats To Eastern Massasaugas
- Habitat destruction and fragmentation Massasaugas need river floodplain wetlands and associated prairie. The draining of marshes and wet prairies for agricultural land has destroyed vital habitat. Although massasaugas can tolerate areas with some degree of agricultural development, they need other habitats as well.
- Unfavorable land management Lack of fire in prairies and marshes has allowed woody vegetation to encroach into open habitats. The invasion of dense stands of maples can adversely affect populations of massasaugas. In instances where controlled burning is done, it may be conducted during periods when snakes are most active and result in snake mortality. Finally, mowing can unintentionally kill or injure active or sunning snakes.
- Human persecution The massasauga is a shy, reclusive, non-aggressive snake that poses little threat to humans. Indiscriminate killing of massasaugas and other snakes and other snakes can reduce local populations. Unchecked collecting of reptile collectors can also reduce populations.
Protection and Management: Steps Toward Recovery
- Restore wetlands and prairie grasslands along river floodplains of north Missouri. Proper floodplain management is critical to the survival of the massasauga. Lands should be managed for a mixture of wetlands, prairie grasslands, and agricultural lands. Wetlands and grasslands should be created in areas that are now predominantly agricultural and in areas where there is a high likelihood of massasauga use.
- Properly manage existing wetlands in order to improve habitat. Use prescribed fires to burn areas utilized by the massasagua to reduce and prevent invasion of woody plants. Prescribed burning should be done before or after the snake's active season (typically before mid-March or after October 30). Burns conducted during the snake's active season should be done on cool, cloudy days. Mow and use stem-applied herbicides where necessary to reduce the amount of woody plants in prairies and wetlands.
- Do not indiscriminatly kill the massasauga or other snakes, and discourage collecting by individuals. Drive with caution along roads that are crossed by massasaugas during migration.
Missouri and federal law prohibits the importation, transportation, sale, purchase, taking, or possession of animals on the State or Federal lists.
For more information on Eastern massasauga, or to report sightings of this species, contact:
Endangered Species Coordinator or Wildlife Ecologist Missouri Department of Conservation Natural History Division P.O. Box 180 Jefferson City, MO 65102 573/751-4115
For more information about wetland restoration of management, contact:
Your Local Natural Resources Conservation Service Office
