The Eastern Massasauga Rattlesnake: - U.S. Fish and Wildlife Service

Land managers have several opportunities to avoid or minimize the influence of habitat
fragmentation. Ideally, massasauga habitat should not be removed if at all possible. When
habitat loss is unavoidable, an effort should be made to avoid bisecting an existing fragment. For
example, placing a deep-water impoundment on the edge of suitable habitat is preferable to
putting it in the middle. When considering how to avoid dividing existing habitat, keep in mind
the seasonal habitat shifts that might be anticipated in the region. Furthermore, the overall
spatial distribution of suitable habitat fragments should be considered. The manager should think
in terms of habitat complexes rather than simply thinking about each patch independently. This
will foster keeping these fragments linked rather than encouraging their isolation.
Land managers may also have opportunities to “repair” fragmentation either by outright
restoration efforts or by the development of suitable corridors. Two adjacent habitat fragments
might be isolated from one another due to the placement of a strip of feed plots between them.
However, leaving a strip of fallow fields or forest in the most direct route between the two
patches might relieve the problem. Corridors that contain habitat attractive to the snakes will
have the greatest likelihood of being used. Although the science behind corridor design is
relatively undeveloped, studies have shown that they are often effective (Beier and Noss 1998).
The design of a corridor will depend upon the species, and will be influenced by a variety of
factors, such as home range size and minimum corridor width (Harrison 1992). Although
corridor designs have not been established for massasaugas, an intuitive notion is that corridors
with small length to width ratios will be the most effective. Snakes that have to travel the least
distance between suitable habitat patches will be better off. Maximizing the width aspect of this
ratio is less straightforward but relates to minimizing the edge to core ratio of the corridor. The
center of a corridor may be more attractive to the snake and safer (Gates and Gysel 1978, Andren
and Angelstam 1988).
Fluctuating Water Levels. Water level fluctuations can have catastrophic effects on
massasaugas if poorly timed or result in permanent habitat loss. The most dire concern is
lowering water levels while snakes are inactive, i.e., during hibernation. Fluctuating water levels
during the overwintering period can cause mortality in two ways. First, hibernating in an aquatic
environment ensures that massasaugas remain in ambient temperatures greater than 0 B C; thus,
lowering the water table during hibernation exposes massasaugas to sub-freezing temperatures
(Carpenter 1953, Maple 1968). Second, hibernating snakes are susceptible to desiccation but by
overwintering in aquatic environments dehydration can be avoided (Costanzo 1989b). Thus,
lowering the water table during hibernation can lead to a premature depletion of massasauga
lipid stores and cause dehydration and mortality. Furthermore, submerging in water conserves
lipids and liver-stored nutrients, which are not only important for inhibiting desiccation (Roberts
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