TIMMERMAN: CROTALUSADAMANTEUSON ORDWAY PRESERVE


areas, summer ranges, and the corridors connecting them. They may be consistent
from year to year (Parker and Brown 1980).
 The second pattern involves movements by snakes that use shifting activity
centers. These snakes continually move over new areas and do not return to
familiar ones--at least not during the same season. Franz (1988) believes this to be
the pattern shown by rat snakes (Elaphe obsoleta quadrivittata and E. guttata) in
north-central Florida. He characterized the annual home range of these species as
consisting of "winter use areas" and "summer use areas" connected by "migratory
corridors," and never saw rat snakes returning to or from these two seasonal
ranges. Several snakes made long distance moves (up to 17 km) along the
migratory corridors. Franz reasons that the abundance of winter den sites available
to the rat snakes in the mild Florida winter, and an inconsistent prey base (see
previous Sigmodon discussion), may account for this pattern.
 The same pattern of shifting activity centers has been reported for certain
Wisconsin populations of the water snake (Nerodia sipedon) during their summer
season (Tiebout and Carey 1987), but its pattern is different from that of Florida rat
snakes. Every fall these temperate-zone water snakes find their way back to the
same unique hibernaculum. Therefore, although they may forage in shifting
ranges, their annual course describes a loop or a circle, since they return to the
original starting point--the winter den site.
 The fourth snake-movement pattern is the one exhibited by C. adamanteus.
In this pattern, snakes have a fairly stable home range and use the same general
area from year to year. There are no discernable migratory routes or summer and
winter ranges. The snakes make somewhat circuitous routes through their
environment often passing over the same terrain at different times of year.
 Employing this movement strategy, the snake becomes thoroughly familiar
with its environment, gaining knowledge through experience. Theoretically, the
success of a sit-and-wait predator should depend on the identification of prime
ambush sites. The diamondback knows its environment well enough to return to
specific favorable locations within its home range. Rattlesnakes were observed
returning to previously used sites on 35 occasions during the course of this study.
For example, M3 used the hollow bottom of a large sweet gum (Liquidambar
styraciflua) snag on the northeast shore of Ross Lake on three separate occasions--
August 1987, September 1987, and May 1988.
 The activity pattern shown by C. adamanteus is similar to that of Ordway
populations of the Florida pine snake (Franz 1984), the eastern coachwhip and the
eastern indigo (Dodd pers. comm.). These snakes have stable home ranges and
may use certain locations more than once during the year.

 Food Habits.- None of the snakes was observed capturing or consuming prey
during the study. Several searches for snake scats at locations recently occupied by
study animals were unsuccessful. Rattlesnakes were detected with stomach bulges
(an indication of feeding) only twice (out of 490 observations), but because snakes