Background/Question/Methods
The Florida Sand Skink (Plestiodon reynoldsi) is a small fossorial lizard with reduced limbs and a slender body, that “swims” through the sands of some of the central ridges of Florida. Because the Florida Sand Skink largely is restricted to the Florida Scrub, and this habitat is becoming increasingly fragmented, the species is listed as Threatened under the Endangered Species Act. The Florida Scrub is a fire-maintained ecosystem, and, because the Florida Sand Skink “swims" just below the surface of the sand, one might speculate that it would prefer areas that are more recently burned, to facilitate locomotion. On the other hand, because the availability of prey items may be restricted, the Florida Sand Skink could prefer areas with a substantial litter layer, in which the species is known to forage. The goal of our study was to establish the relationship between fire history and Florida Sand Skink abundance. The study was conducted at Archbold Biological Station, at the southern end of the Lake Wales Ridge in Highlands County. In March of 2007, we installed 36 large (0.04 ha) enclosures at the Station, equally distributed among three categories of time since last fire: less than 5 years, 6 to 17 years, and 17 to 40 years. The enclosures were saturated with drift fence-pitfall trap arrays, the traps were monitored throughout the active season, and captured individuals were marked. Removal (by marking) was used to estimate the absolute number of individuals per enclosure. We present the results from three years of sampling (2007-2009). We also present some findings concerning the immediate response of individuals to burning, emanating from planned burning of five of the enclosures in 2008.
Results/Conclusions We observed increasing abundances of individuals with increasing time since fire. Highest abundances were found in areas not burned for 17 years or longer. Leaf litter biomass was the strongest environmental correlate of abundance. Leaf litter biomass co-varied with time since fire, as expected, which leads us to suggest that the litter layer is an important environmental feature for the Florida Sand Skinks, because it provides a relatively abundant food source. Few individuals were killed directly by the planned burn and we could detect no effect on abundance after about seven months. Although the Florida Sand Skink appears to be well-suited to living in a fire-maintained ecosystem, our results suggest that it prefers areas where the fire-return interval is relatively long.