Download NUMBER OF GOPHER TORTOISE BURROWS AT JONATHAN DICKINSON STATE PARK

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