TIMMERMAN: CROTALUSADAMANTEUS ON ORDWAY PRESERVE


 Habitats were determined by a visual inspection of the environment and by
reference to Ordway vegetation maps (Franz unpubl. data; Myers 1984). Since it
was often difficult to distinguish between Mesic Hammocks and Swamp Forests on
aerial photographs, these forests were combined for habitat analysis. Swamps were
not inundated with water and looked superficially like extensions of the mesic
forests for most of the study. Habitat utilization-availability analyses included a
Pearson's Chi-square goodness-of-fit test and a Bonferroni
simultaneous-confidence-intervals test. Both tests made comparisons between
expected use and observed use for all habitats within each snake's range. The
Pearson's Chi-square test was used to determine if snakes used the various habitats
in proportion to their availability. Selection for or against certain habitats was
evaluated using Bonferroni confidence intervals (Byers et al. 1984).
 For the habitat analyses, the cumulative number of days that the snake was
seen to occupy a certain area was used instead of the actual number of field
observations. In other words, if the snake was visited on Monday, Wednesday, and
Friday and had occupied the same site or a closely knit constellation of sites in a
particular habitat, then five observation-days were scored for that particular habitat
even though the snake had not been observed using it every day of that period. For
an ambush hunter like the diamondback, the inclusion of these intermediate
periods should more accurately reflect the proportions of time spent in various
habitats. I decided on this procedure when preliminary 24-hour tracking bouts
showed me that these snakes maintain their ambush positions hour after hour, and
sometimes day after day. Additionally, for those times when snakes were not
observed daily, the number of observation-days assigned to habitat-use were split
evenly between two habitats when a snake moved from one habitat to another.


 RESULTS AND DISCUSSION


 Eight eastern diamondback rattlesnakes (five males and three females) were
radio-tracked for varying periods of time. An additional five snakes were
implanted, but they did not contribute sufficient data, due mostly to transmitter
failure. Home ranges were plotted for six snakes (four males and two females)
tracked eight months or more. Ordway rattlesnakes were radio-tracked for
durations ranging from 33 days (11 observations) for a small female, to 864 days
(245 observations) for an adult male. Intervals between observations ranged from
1.5 hours to 20 days (mean = 3.3 days). The longer intervals were caused by
snakes that retreated to inaccessible areas of the preserve.

 Home Range.- Six snakes were radio-tracked for a minimum of eight
months, including Male Number 3 (M3), who was followed for two consecutive