Presented by Jacob Owen

1. “Mitigation Measures to Reduce Highway Mortality of Turtles and Other Herpetofauna at a North Florida Lake” Presented by Jacob Owen Aresco, M.J. 2005. Mitigation measures to reduce highway mortality of turtles and other herpetofauna at a north Florida lake. Journal of Wildlife Management 69:549-560.

2. Study Organism Reptiles and Amphibians Primarily Turtles Study Site U.S. Highway 27 Lake Jackson, Florida Questions Mortality rate of a 4-lane highway during a drought. Effectiveness of reducing mortality with a drift fence system along drainage culvert

3. Results High attempts with very high mortality Pre-fence mortality much higher than post-fence (even with an increase in traffic) Implications Massive losses may lead to bottleneck effects and a population sink (Pulliam 1988) Conservation measures along roads near wetlands

4. Highway Effects on Reptiles and Amphibians

5. Study Site

6. Methods • Monitoring and Fence Design • Mark-recapture of Turtles • Evaluating the Effectiveness of Temporary Fences • Probability of road Mortality in an Attempted Crossing

7. Gibbs and Shriver 2002 Hels and Buchwald 2001

8. Results • Highway Monitoring • -8,842; 10 species of turtles • -838; 10 species of frogs • -363; 15 species of snakes • -152; 6 species of lizards • -32 American alligators • -2 salamanders from 2 species • Road Mortality and Attempted Crossings of Turtles • -367 turtles dead on road pre-fence • -6 turtles dead on road post-fence • -33% of marked turtles were recaptured

9. Results • Probability of Road Mortality in an Attempted Crossing • -95% of 343 turtles killed as they entered highway (other 5% killed in first two lanes) • Efficacy of the Drift Fences for Turtles • -Chi-square=11.6; p-value=0.001 • Road Mortality of Other Herpetofauna and Efficacy of • Temporary Fences • -26% of total 1,088 individuals were found DOR and 74% found AAF

10. Discussion • Non-random movement • Migration • Fence diverted approximately 98% of turtle deaths

11. Discussion • Nesting and dispersal • Increased traffic in rural areas-habitat destruction (Ch. 9 Primack 2010) • More traffic mortality studies for comparison

13. Conservation & Management Implications • The drift fence needs modification due to turtles climbing and more constant monitoring • Species of concern: Gopher tortoise and Suwanee cooter • Reducing bottleneck effect and population sinks • Bottleneck Effect=a sharp reduction in size of a population due to environmental stochastic events (such as earthquakes, floods, fires, or droughts) or human activities. (Ch. 11 Primack 2010) • Population Sink= A breeding group that does not produce enough offspring to maintain itself in coming years without immigrants from other populations.

14. Bibliography ARESCO, M.J. 2005. Mitigation measures to reduce highway mortality of turtles and other herpetofauna at a north Florida lake. Journal of Wildlife Management 69:549-560. BURKE, V. and J.W. GIBBONS. 1995. Terrestrial buffer zones and wetland conservation: a case study of freshwater turtles in a Carolina bay. Conservation Biology 9:1365-1369. FLORIDA DEPARTMENT OF TRANSPORTATION. 2002. AADT historical traffic statistics. Transportation Statistics Office, Tallahassee, Florida, USA. GIBBS, J.P. and W.G. SHRIVER. 2002. Estimating the effects of road mortality on turtle populations. Conservation Biology 16:1647-1652. HELS, T., and E. BUCHWALD. 2001. The effect of road kills on amphibian populations. Biological Conservation 99:331-340. NATIONAL RESEARCH COUNCIL. 1997. Towards a sustainable future: addressing the long-term effects of motor vehicle transportation on climate and ecology. National Academy Press, Washington, D.C., USA. PRIMACK, R.B. 2010. Essentials of Conservation biology, fifth edition. Sinauer Associates, Sunderland, Massachusetts. PULLIAM, H.R. 1988. Sources, sinks, and population regulation. American Naturalist 132:652-661.

15. Questions??