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Identification
This is
a large, stout-bodied snake that can obtain lengths of five feet or more. Along
with its sheer size and characteristic rattle, this snake
can be readily identified by the presence of dark bands, or chevrons, running
across its back. Its relatively large, angular head possesses deep, heat-sensing
"pits" near the
eyes and nostrils. Coloration of the Timber Rattlesnake is highly variable and
ranges from sulfur yellow to brown, gray or black. Range alone is often adequate
to identify this snake as it is frequently the only rattlesnake in much of the
central and eastern portions of the United States.
Distribution and Status
Timber Rattlesnakes have a wide distribution ranging from New Hampshire south
to Texas, encompassing a total of 30 states (US
distribution map; Midwest
distribution map). The Timber Rattlesnake is listed as state Endangered
in Indiana and Ohio, and state Threatened in Illinois and Minnesota. The species
is listed as Protected in Iowa and Missouri, and is a Protected Wild Animal
in Wisconsin. The Timber Rattlesnake is absent from Michigan. Click HERE
for state by state status descriptions.
Ecology
The Timber Rattlesnake is highly dependent on the existence of suitable winter
denning habitat. While these areas do vary across the timber's geographic
range, they are generally associated with rocky outcroppings or talus slopes
where crevices can afford the snakes protection over the winter months.
In some areas, timbers may also hibernate in rodent burrows, or below vegetative
root systems. These denning sites are typically found in forested areas, including
forested riparian zones. The diet of the Timber Rattlesnake consists mostly
of rodents, and common prey includes chipmunks, mice, and squirrels. The species
relies heavily on sense of smell, and their dietary tactic involves lying motionless
in animal runways to ambush their prey. Timber Rattlesnakes are a long-lived
species, often living to 20 years or more. An interesting fact about Timber
Rattlesnakes is that they will return to the same den year after year in order
to hibernate through the winter months. Click HERE to see the Timber
Rattlesnake's foraging posture.
Threats and Management Issues
Habitat loss and fragmentation are the chief threats facing Timber Rattlesnakes.
While at one time the species was considered relatively ubiquitous across its
range, most surviving populations today are considerably isolated. Human persecution
and harvesting have also had devastating affects on this species. Timber Rattlesnakes
are known to den communally, and in the same location year after year. Because
of this, den sites are particularly sensitive areas and should be a high priority
for protection. In some areas, Timber Rattlesnake levels have dropped to critically
low levels as a result of dens being abused and used as activity centers from
which to collect snakes. While the Timber Rattlesnake is poisonous, it is not
an aggressive species. In fact, the majority of documented bites have occurred
while individuals were trying to pick the snakes up. Land managers and owners
may find the Habitat
Management Guidelines for Reptiles and Amphibians of the Midwest useful
when making habitat management and conservation decisions involving habitats
that may support Timber Rattlesnakes.
Resources
General reference guides
and websites.
Bruce Kingsbury, Director
Center for Reptile and Amphibian Conservation and Management
Science Building
Indiana-Purdue University
2101 East Coliseum Blvd.
Fort Wayne, IN 46805-1499