TIMMERMAN: CROTALUSADAMANTEUS ON ORDWAY PRESERVE


 The eastern diamondback, which is an important predator on rodents and
lagamorphs, is declining in numbers, and like other snakes that possess large home
ranges, will continue to face threats from human development that fragments their
environment. Although the diamondback's real threat to public safety is very low
(more people are killed every year by lightning strikes and bee stings), the
perceived threat by the public is still quite high. Given this situation, the
probability for future diamondback survival anywhere but on wildlife preserves and
other large tracts of land is probably low unless conservation measures are taken.
It would indeed be a tragic turn of events if this magnificent reptile, which figures
prominently in southern legend and literature, should disappear from our
landscape.

 Management Implications.- C. adamanteus is native to many of Florida's
vegetative communities. These natural areas, and the wildlife in them, have
evolved in the presence of natural fires (Dye 1989). Management practices for
areas containing eastern diamondback rattlesnakes should be consistent with an
ecosystem or natural-resource management approach, similar to the kind
advocated by the Florida Park Service (Glisson and Perry 1994). The control of
exotic plants that invade and threaten ecosystems (Doren 1991) and the use of
prescribed fire (Dye 1989) should be implemented. In addition, the natural
maturation of riparian areas containing mesic and swamp habitats should be
allowed, since these are often high-use foraging areas for these rattlesnakes. The
gopher tortoise, a keystone species to many sandhill creatures (Eisenberg 1983), is
also important to rattlesnakes at various times. During the winter, snakes may use
the tortoise den as a refugium. During the fall, it is known that gravid females
sometimes use "gopher holes" as parturition sites. Various animals relying on the
gopher tortoise for survival, such as the Florida mouse (Podomysfloridanus), may
also be important components in the diet of baby rattlesnakes. Any management
plans under consideration for C. adamanteus should include G. polyphemus
whenever present.
 All rattlesnake-prey species expected to be found at the Katharine Ordway
Preserve occur there, but population levels are often lower than would be expected
(Eisenberg pers. comm.). Under this situation, rattlesnakes cannot focus their
foraging efforts on Sylvilagus and Sigmodon, abundant prey over most of the
southeast. Here, management schemes must insure the health of small mammal
communities in the mesic and xeric forests, areas shown to be used preferentially
by Ordway diamondbacks.
 If unnaturally high numbers of C. adamanteus are wished for, managers
should consider artificially raising the numbers of the snake's prey base,
particularly rabbits and cotton rats. I believe food to be the prime limiting factor
for these snakes. Considering the number of winter observations that identified
Dasypus burrows as refugia for Ordway diamondbacks, management plans that
may adversely affect populations of the armadillo should be studied carefully. The