Tortoise food preferences

After graduating from NC State, I worked on an independent project to study gopher tortoise habitat and food preference at the Barefoot Beach Preserve in Collier County, FL with Dr. Nora Demers of Florida Gulf Coast University (FGCU). Gopher tortoises (Gopherus polyphemus) are an important occupant of Florida’s great and diverse habitats; these animals can reside in a range of sandy uplands, including sandhills, scrub, pine flatwoods and coastal dunes. G. polyphemus burrows are an indispensable resource for many species including rattlesnakes, mice, and burrowing owls, making them a keystone species on which vertebrates and invertebrates alike depend. Therefore, it is no wonder why many national, state, and county preserves are looking to protect gopher tortoises on their lands.

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Gopher tortoise, Gopherus polyphemus

Gopher tortoise populations have recently been on the decline, primarily due to the increase in land development and the disturbance of natural processes, such as wildfires. Fire in the natural environment promotes community succession, and the small-statured, herbaceous species on which gopher tortoises depend for foraging are found in early successional stages, which thrive after burning events. It has been observed that gopher tortoises are significantly more common in areas of recent burning than in areas that are undergoing fire suppression. These areas are characterized by lower canopy density and increased areas of open ground. 

Since many preserves do not mandate burning as an appropriate habitat management practice because of the dangers to nearby human populations, we propose a solution that could be both safe for humans and improve habitats for gopher tortoises. Cutting and removal of understory species has been used to restore gopher tortoise habitats in areas where fire burning is not permitted. However, the effects of understory cutting on gopher tortoise foraging behavior is still uncertain. 

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For my independent project with FGCU, I tested the possibility of using understory cutting to promote small herbaceous species on which gopher tortoise depend. This study observed the behavior of gopher tortoises at Barefoot Beach County Preserve in Bonita Springs, Florida to help better understand the foraging preferences of this species in managed and unmanaged habitats. We tested whether areas within the preserve that had undergone understory cutting were more preferable to gopher tortoises by observing foraging behaviors within cut and uncut areas, and predicted that the site with the most recent cutting would be preferred over all other sites. The data show a high propensity of gopher tortoises to consume grasses over any other plant group. Furthermore, we also found that the proportion of foraging behavior was greater at the treatment site than at the control site.

Barefoot Beach Preserve, Collier County, FL

Overall, I found that selective plant removal led to changes in plant diversity that promoted gopher tortoise foraging behavior. I wrote an Executive Research Report for Collier County Parks and Recreation, which led to an extension of this habitat management program. The Friends of Barefoot Beach Preserve also granted me a Research Scholarship to present a research poster at the 2017 Annual Gopher Tortoise Council Meeting. 

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