Seasonal and Diel Gopher Tortoise (Gopherus polyphemus) Activity and Burrow Use by Commensals in Coastal Beach Dune Habitat as Examined by Wildlife Cameras

Abstract. – Gopher tortoises (Gopherus polyphemus), the only land tortoises native to the southeastern United States, are found throughout their range in a variety of upland habitat types, with their use of upland pine-dominated habitats receiving most attention. Fewer studies have examined their use of coastal beach dune habitats, but some of the highest gopher tortoise burrow densities have been observed in this vulnerable, yet critical, habitat. Gopher tortoises construct extensive burrows for their own use, and these burrows have also been shown to support numerous other animals (i.e., commensal species) that may depend on them for critical needs (e.g., shelter, food). Motion-activated wildlife cameras allow for nonintrusive and continuous observation of burrow activity with minimal disturbance to the animals and habitat. Here we examined 10 gopher tortoise burrows over a 12-mo period using motion-activated wildlife cameras in beach dune habitat in an undeveloped section of coastline in northeast Florida. Gopher tortoises were most frequently observed during the spring and summer months (April–August), and most often during daylight hours. Gopher tortoise behaviors such as burrow maintenance, mating, foraging, and resting were all observed more during April through August, which is a slightly earlier start than these activities have been observed in inland populations. We observed a commensal community of 51 animal taxa using tortoise burrows and their aprons, 29 of which we were able to identify to species. The commensal community was generally similar to those in inland habitats, but we did observe some taxa that were previously undocumented at gopher tortoise burrows including 2 bird species and 8 insect taxa. These commensals displayed varied diel and seasonal activity patterns, with many taxa observed at burrows concurrently occupied by gopher tortoises. Considered together, our observations of gopher tortoise behavior and their commensal community in coastal beach dunes provide valuable insights into the importance of this understudied habitat and highlight distinct differences from inland ecosystems.