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NUMBER OF GOPHER TORTOISE BURROWS AT JONATHAN DICKINSON STATE PARK By Alejandro Garcia INTRODUCTION • Gopher Tortoise • Gopherus polyphemus • Long lived • Upland Habitats • Scrubs, pastures, etc. • Herbivores • Grasses, fruit, etc. • Known for long burrows • 48.5 Ft Photo Credit: Alejandro Garcia INTRODUCTION (CONT.) • Keystone species • House >350 species • Threatened • Populations on the decline • Nest Predators – armadillos, raccoons, foxes, skunks, alligators • >90% • Human Predation Photo Credit: Alejandro Garcia INTRODUCTION (CONT.) • Habitat loss • Habitat degradation • Fire • Loss of fire promotes forest succession Photo Credit: Alejandro Garcia OBJECTIVES • See if there is a significant difference in total number of burrows in areas of higher burn frequency vs. lower burn frequency. • Verify that Jonathan Dickinson State Park (JDSP) burn program is effective. • Hypothesis: There are significantly more gopher tortoise burrows in high burn frequency zones than in low burn frequency zones. Photo Credit: Alejandro Garcia SITE DESCRIPTION • JDSP • 12 miles south of Stuart on US1 • 11,470.94 acres • Broken up into burn zones, separated by burn roads • Different burn zones are burned at different times and different rates SITE DESCRIPTION (CONT.) • Burn zones surveyed • High Burn Frequency (6-7 from 1972) • B26 • D06 • D07 • G05 • Low Burn Frequency (2-3 from 1972) • B15 • B19 • C10 • Selected because they contained scrubby flatwoods DATA COLLECTION • Surveys done from January 28 - April 1, 2015 • Mapped out beforehand • Transects 52.5 ft x 820 ft • Easy to lose bearings, team members used compasses DATA COLLECTION • Burrows located by: • looking for aprons • shape of hole • Once tortoise burrow found: • width measured • marked with GPS • vegetation noted • marked as Active, Inactive, or Abandoned Photo Credit: Natasha Warraich RESULTS Total Number of Gopher Tortoise Burrows 100 • There were significantly more (Student Ttest; p<0.05) gopher tortoise burrows in areas of high burn frequencies. • Found 0 in B19. 90 80 70 60 50 • Found up to 12 in other transects. Total Number of Gopher Tortoise Burrows 40 30 20 10 0 Low Burn Frequency High Burn Frequency DISCUSSION • The significant difference was due to difference in burn frequency. • Gopher tortoises need sunlight, grasses, and loose soil. • Fire promotes this. Photo Credit: Alejandro Garcia DISCUSSION (CONT.) • Lack of fire promotes the opposite. • Major shrub growth • Lack of grasses • On the basis of this study, more research needs to be done. • Larger scale studies Photo Credit: Alejandro Garcia ACKNOWLEDGEMENTS • JDSP • Natasha Warraich • Rob Rossmanith • Juliana Osorio • Amber Collins • Dr. Miles Photo Credit: Natasha Warraich WORKS CITED • Ashton, K. G., Engelhardt, B. M., & Branciforte, B. S. (2008). Gopher Tortoise (Gopheruspolyphemus) abundance and distribution after prescribed fire reintroduction to Florida scrub and sandhill at Archbold Biological Station. Applied Herpetology42:523-529. • Carlson, P. C., Tanner, G. W., Wood, J. M., Humphrey, S. R. (1993). Fire in Key Deer habitat improves browse, prevents succession, and preserves endemic herbs. The Journal of Wildlife Management 57:914-928. • Diemer, J. E. (1986). The ecology and management of the gopher tortoise in the southeastern United States. Herpetologica 42:125-133. • McCoy, E. D., Mushinsky, H. R., & Lindzey, J. (2006). Declines of the gopher tortoise on protected lands. Biological Conservation128:120-127. • Smith, L. L., Steen, D. A., Connor, L. M., Rutledge, J. C. (2013). Effects of predator exclusion on nest and hatchling survival in the gopher tortoise. Journal of Wildlife Management 77:352-358. • State of Florida Department of Environmental Protection. Jonathan Dickinson State Park: Approved Unit Management Plan. Division of Recreation and Parks, 2012. • State of Florida Department of Environmental Protection. Jonathan Dickinson State Park: • Approved Unit Management Plan. Division of Recreation and Parks, 2012. QUESTIONS Photo Credit: Alejandro Garcia