DODD & FRANZ: UPLAND SNAKES


Table 2. Niche breadth for four most abundant snakes trapped in uplands on the Katharine Ordway Preserve-
Swisher Memorial Sanctuary, Putnam County, Florida.

 Species

 Coluber Masticophis Micrurus Sistrurus
 Parameter constrictor flagellum fulvius miliarius


 Habitat 0.934 0.795 0.775 0.657
 Season 0.804 0.829 0.742 0.844



 (556.6 mm, N=61) than in open xeric hammock (665.9 mm, N=31) and closed
 xeric hammock (686.7 mm, N=19). The difference among means is significant
 (X2=16.84, df-2, p=0.0002). The mean SVL of Coluber in mesic habitats was
 752.4 mm (N=25).


 Seasonal Abundance


 With the exception of Cemophora, at least one specimen of the five most
common species was caught each month of the study. In 1989, the majority of C.
constrictor was trapped during the first 12 weeks of the survey (i.e. from early
April through mid-June) with later peaks in late August to early September and
again in late October (Fig. 4). Micrurus fulvius were trapped most often in early
May, but capture sharply dropped thereafter, whereas S. miliarius were trapped
throughout the sampling period with a slight peak in the early autumn. No general
patterns of seasonal capture are apparent for the other two most commonly trapped
xeric habitat species. Cemophora coccinea was trapped only during the warmer
months (Fig. 4), and Masticophis flagellum was trapped at low levels nearly
throughout the sampling period. When temporal sampling periods were matched,
more individuals were caught in 1990 than in 1989 for four of the five most
commonly trapped species (Fig. 5). Seasonal values for niche overlap are in Table
1 and niche breadth in Table 2.
 Inasmuch as all traps were not open simultaneously throughout the potential
snake activity period in mesic habitats, it is not possible to determine seasonal
activity patterns unless sampling effort is considered. Figure 6 shows total monthly
snake capture in mesic habitats in relation to sampling effort during that month. A
peak of snake activity is apparent in March. From April to August, the number of
snakes trapped was proportional to sampling effort. In September and October, trap