Environmental Characteristics of Nest Sites Selected by Gopher Tortoises (Gopherus polyphemus) in Southern Mississippi

Jennifer Y. Lamb, University of Southern Mississippi
Joshua R. Ennen
Carl P. Qualls, University of Southern Mississippi


Nest-site selection can influence both the survivorship of a clutch of eggs as well as the phenotype of resulting hatchlings. The purpose of this study was to determine whether nest sites of Gopherus polyphemus in southern Mississippi differed from randomly chosen prospective nest sites with respect to various habitat parameters. Data were collected that described habitat variables we thought could be biologically relevant. Univariate tests were used to both compare nest sites with non nest sites, as well as to further narrow the list of variables into those included in an analysis with Akaike's Information Criterion (AIC). Our AIC analysis suggests that the amount of bare soil at the apron and the composition of the soil are important factors when modeling nest-site selection for this tortoise. Aprons with nests contained more bare soil (less vegetation and litter cover) and less clay content in the soil than did randomly chosen aprons that did not have nests. These results indicate that nest sites of G. polyphemus in southern Mississippi differ from random, potential nest sites, implying that females exhibit nest-site selection.