Is the Florida Sand Skink (Plestiodon reynoldsi) a Dietary Specialist?

Abstract

We examined the question of whether an apparently restricted diet qualifies the Florida sand skink (Plestiodon reynoldsi) as a dietary specialist. We gathered diet data from the three existing sources, added new data from individuals that we collected, and used these data to calculate measures of dietary diversity. We compared the diet of P. reynoldsi with those of 25 species of skinks, nine species of fossorial squamates, and six species of lizards and snakes found in habitats similar to those occupied by P. reynoldsi. We estimated diet choice indirectly and applied standards of specialization drawn from the literature. In every regard, the Florida sand skink did not seem to have a restricted diet. Dietary diversity values for the species are near the center of the distribution of values for skinks and for the species found in similar habitats. The species has a higher than expected H′ value, based on the identity of its main prey, and the highest or nearly highest dietary diversity values among the fossorial species examined. The diet of the species did not stabilize over the course of four diet studies; rather, the cumulative number of prey types taken nearly doubled. We suggest that the apparently restricted diet of P. reynoldsi reflects the restricted prey choices provided by its foraging sites. A major problem in studying dietary specialization is the lack of data on prey availability and therefore a lack of solid information on diet choice.