THREATS
TO THE HIBERNACULUM
The hibernacula are not easy to
identify, and are susceptible to inadvertent destruction in the course
of development projects. Hibernation sites may be destroyed by
excavation, burial, or flooding. Since eastern massasauga rattlesnakes
typically hibernate in water-saturated soils, hibernation sites may
also be adversely affected by drainage. However, too little is known
about the physical conditions within rattlesnake
hibernacula to predict how development might affect a site’s
integrity. Conceivably, even the removal of several trees could
sufficiently alter local soil moisture conditions to affect nearby
hibernacula.
The destruction of hibernation sites in
the winter would obviously result in the death of its occupants.
However, because the snakes use the sites repeatedly (known as site
fidelity), individuals whose over-wintering sites are destroyed during
the summer (when the site is not occupied) would also be likely to
suffer mortality. Scientists suspect that massasaugas will search for
their destroyed hibernaculum even to the point of being killed by cold
temperatures.
EMERGENCE
As spring approaches, the air and ground surrounding the outside of
the hibernaculum begins to warm. This temperature increase will slowly
cause the inside of the chamber to warm, usually in late April. The
snake will slowly move closer to the entrance as the days continue to
get warmer. The snake’s metabolism will increase and, in turn,
alertness, heart rate, and intake of oxygen will return to normal. As
a precaution, massasaugas remain near the hibernaculum to bask, until
the
threat of snow or cold weather is eliminated. In May, the snake moves
back to its summer habitat.