BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 38 PT. 1(2)


habitat data, we tabulated the number of individuals trapped during each biweekly
sampling period for the five most commonly trapped species as well as the mean
number of days between captures at each trap for all species combined.
 We divided the 1989 xeric sampling season into three general periods: Spring
(biweekly sampling periods 1-4, 4 April-29 May); Summer (periods 5-12, 30 May-
18 September); Autumn (periods 13-17, 19 September-17 November). We
computed Hurlbert's measure of niche overlap (L) (Hurlbert 1978) for the five most
abundant snakes because resource states, i.e. amounts of available habitat and
seasonal activity, varied in abundance during the sampling period (Krebs 1989).
Hurlbert's measure of niche breadth (B) was calculated for the four most abundant
snakes, because it is sensitive to the selectivity of rare resources (Hurlbert 1978;
Krebs 1989). The scarlet snake (Cemophora coccinea) was excluded, because it
was not trapped in open xeric hammock.
 A sufficient sample size was available to compare snout-vent lengths of black
racers (Coluber constrictor) among xeric habitat types to determine if size-related
habitat partitioning occurred. The data on snout-vent lengths in different habitats
first were tested for normality. Inasmuch as the data were not normally distributed,
comparisons were made using the nonparametric procedure NPARIWAY which
corresponds to a Kruskal-Wallis test (SAS Institute, Inc. 1988).
 The effects of monthly rainfall and monthly maximum, minimum, and
average temperatures on the total number of snakes trapped were examined using
Spearman Rank Correlation. Statistical analyses were performed using the SAS
program for microcomputers (SAS Institute, Inc. 1988), ABSTAT version 4
(Anderson Bell 1987), and ecological programs in Krebs (1988). The level of
significance was set at a. = 0.05.


 RESULTS

 Habitat Associations


 We captured 10 snake species (234 individuals plus 48 recaptures) in xeric
habitats (Fig. 2) and 11 species (42 individuals plus 5 recaptures) in mesic habitats
(Fig. 3). A few snakes were captured by hand (7) while checking traps and data
from these snakes are included in the results that follow, where appropriate. Most
recaptures occurred within a few days at the same or a nearby trap. The most
commonly trapped snake in both habitat types was the black racer. The next most
commonly captured species were trapped primarily in the xeric habitats, including
the coachwhip (Masticophis flagellum), coral snake (Micrurus fulvius), and the
pygmy rattlesnake (Sistrurus miliarius). Small snake species known from the
Ordway Preserve (Diadophis punctatus, Opheodrys aestivus, Regina alleni,
Seminatrix pygaea, Tantilla relicta) (Franz this vol.) were never trapped.