BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 38, PT. 1(5)


 Behavior.- Eastern diamondbacks were usually seen tightly coiled (373 obs.,
76.1% of obs.) in a position from which they could ambush prey. They spent
anywhere from one day to a week coiled in the same position. The snakes were
seen in a loosely coiled position in 77 cases (15.7% of obs., Table 6). The function
of this "loose" position is unknown, although Martin (1987) thought that these
configurations were related to thermoregulatory behavior. Outside of the winter
season, Ordway diamondbacks seem to spend little or no effort at thermoregulating
as far as I can determine. In this respect, the species also is similar to the
cottonmouth (Cook 1983).
 Snakes were almost entirely terrestrial, spending almost no time above the
surface of the ground, and spending little time below the surface (Table 7). The
only observation of the diamondback's climbing ability was made on 6 Oct 1985 at
0913 hrs when M2 was seen about 1 m off the ground, coiled in a leaning turkey
oak tree in High Pine Forest. The ambient air temperature was 190 C and the
snake's core body temperature was 160 C. Perhaps the snake was attempting to
thermoregulate by positioning itself in the direct sun. In general, the eastern
diamondback rattlesnake is a very poor climber, rarely getting off the ground more
than a meter. This is borne out by this study and by the observations of numerous
colleagues. It is difficult to accept the observation of Rutledge (1936), who
claimed to have seen an adult diamondback 15 feet high in a tree, and another in
the nest of a woodpecker after it had eaten the resident bird and several eggs. In
addition, although we know that any rattlesnake may occasionally climb into a low
tree or bush, the statement by Ernst (1992) that the diamondback's "activity is not
restricted to ground level" is too strong. C. adamanteus rarely climbs for any
reason.
 During the summer, snakes were seen on the surface 91.8% of the time (403
obs.). They were observed using burrows or other refuges below the surface on
only 35 occasions (8.0 %). In winter, burrow use was more common, yet
diamondbacks sought refuge below ground only 44.6 % of the time (95 obs.). In
addition, they were occasionally seen above ground during weather so cool that it
was uncomfortable to the human researchers accustomed to Ordway summers.
 As an extreme example of this behavior, Fl spent the night of 26 January
1988 coiled on the forest floor in a mesic hammock near Goose Lake when the
minimum temperature recorded in a xeric hammock 1.5 km away was -20 C.
Although it is likely that the vegetation of a mesic hammock would ameliorate
conditions by a degree or two, this would still be one of the lowest reported
voluntary temperatures tolerated by any species of snake, including Vipera berus, a
snake that ranges slightly above the Arctic circle (Lillywhite 1987).
 Means (1985) observed the same behavior by Tall Timbers rattlesnakes in the
winter. He reported that rattlesnakes there became so frost-bitten by rapidly
moving cold fronts that they were forced to retreat to an underground refugium for