Eastern Massasauga Rattlesnake
Sistrurus catenatus catenatus
massasauga rattlesnake is a Federal candidate species. Candidate species
are those species for which the Service has sufficient information
on their biological status and threats to propose them as endangered
or threatnened. Candidate species receive no legal protection, however,
conservation is encouraged since they may warrant future protection
under the Endangered Species Act.
What is an eastern
Name - Sistrurus catenatus catenatus
Appearance - Massasaugas are small snakes with thick bodies, heart-shaped heads
and vertical pupils. The average length of an adult is about 2 feet.
Adult massasaugas are gray or light brown with large, light-edged
chocolate brown blotches on the back and smaller blotches on the sides.
The snake's belly is marbled dark gray or black and there is a narrow,
white stripe on its head. Its tail has several dark brown rings and
is tipped by gray-yellow horny rattles. Young snakes have the same
markings, but are more vividly colored. The head is a triangular shape
and the pupils are vertical.
Habitat - Massasaugas live in wet areas including wet prairies, marshes and
low areas along rivers and lakes. In many areas massasaugas also use
adjacent uplands during part of the year. They often hibernate in
crayfish burrows but they may also be found under logs and tree roots
or in small mammal burrows. Unlike other rattlesnakes, massasaugas
Reproduction - Like all rattlesnakes, massasaugas bear live young. The young actually
hatch from eggs while still in the female's body. Depending on the
health of the individual, adult females may bear young every year
or every other year. When food is especially scarce they may only
have young every three years. Massasaugas that have young every year,
mate in the spring and bear their young in late summer or early fall.
In contrast, snakes that have young every other year, mate in autumn
and bear young the next summer. Litter size varies from 5 to 19 young.
Habits - Massasaugas eat small rodents like mice and voles but they will
sometimes eat frogs and other snakes. They hunt by sitting and waiting.
Heat sensitive pits near the snakes' eyes alert the snake to the presence
of prey. They can find their prey by sight, by feeling vibrations,
by sensing heat given off by their prey, and/or by detecting chemicals
given off by the animal (like odors).
Range - Eastern
massasaugas live in an area that extends from western New York and
southern Ontario to southern Iowa. Historically, the snake's range covered this same area,
but within this large area the number of populations and the number
of snakes within populations have steadily shrunk. The eastern massasauga
is generally found in small, isolated populations throughout its range.
Today, the massasauga is listed as endangered, threatened, or a species
of concern in every state and province in which it lives.
Why is the eastern
massasauga a candidate species?
Eradication - People seem to have an innate fear of snakes and fear of venomous
snakes is particularly strong. Therefore, not only are massasaugas
killed when they show up near homes or businesses, but people may
go out of their way to kill or even eliminate them. Indeed, many states
had bounties on all rattlesnakes, including massasaugas.
loss - Massasaugas depend on wetlands for food and shelter but often use
nearby upland areas during part of the year. Draining wetlands for
farms, roads, homes, and urban development has eliminated much of
the massasauga habitat in many states. Also, massasaugas are not long
distance travelers, so roads, towns, and farm fields prevent them
from moving between the wetland and upland habitats they need. These
same barriers also separate and isolate remaining populations from
each other. Small, isolated populations often continue on a downward
spiral until the massasauga is lost from those areas.
being done to conserve the eastern massasauga?
Research - Researchers are studying the eastern massasauga to learn about its
life history, about how it uses its habitat, and how we can manage
for it and its habitat.
Management - Many of the remaining populations of massasaugas are on public land
and privately owned natural areas. Some land management practices
on those properties harm massasaugas. The Service is working with
willing land managers to practice techniques that allow traditional
management goals to continue but avoid harming the massasauga and
are docile, secretive snakes that will try to escape rather than
fight. But they will protect themselves and may bite if cornered.
Be cautious in massasauga areas by wearing leather boots or shoes,
watching where you place your hands and feet and walking around,
rather than over, fallen logs. Treat massasaugas with respect,
like any wild animal. If you are bitten by a massasauga, seek
medical help immediately.
many people have an innate fear of massasaugas, it is actually a secretive,
docile snake that strikes humans only when it feels threatened and
cornered. Living, working, or recreating in massasauga areas does
require caution, but the massasauga is also an important and beautiful
part of the natural heritage of those areas. We hope that education
about the docile nature of the snake, its habits, and its role in
the ecosystem will help people feel more comfortable living with this
Why do we want
to conserve the eastern massasauga?
Role - The massasauga plays an important role in its ecosystems, both as
a predator on small mammals, other snakes, and amphibians and as prey
for hawks, owls, cranes, and some mammals.
Species - The fact that massasaugas are in serious decline is a warning bell
telling us that something is wrong. The story of the massasauga is
similar to the story of many species of plants and animals that need
wetlands and/or a combination of wetlands and uplands to survive.
When we drain wetlands and develop in natural areas, we push our wild
plants and animals onto ever smaller isolated islands of habitat where
it is difficult for them to survive. By conserving massasaugas, we
conserve natural systems that support many species of plants and animals.
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