Study of highway construction mitigation leads down an unexpected road: Concurrent die-offs of turtles,
salamanders, and frogs at one site in Maryland, USA
Scott D. Farnsworth1 and Richard A. Seigel2
1School of Biological Sciences Washington State University, Pullman, WA USA2 Department of Biological Sciences, Towson University, Towson, MD USA
Several problems of translocation
• Generally involve moving long distances well outside animal’s home range (Off-Site)
– Outbreeding depression
– Unfamiliarity of where to find suitable habitat for nesting, foraging, refugia
– Homing behavior
– Possible disease spread
– Higher mortality
On-site translocation may eliminate some of these problems
• When suitable habitat is available adjacent to area under development
• Animals are moved but remain in same population and within some portion of home range
Box turtles good model for on-site translocation study
• Adult survival (~95+ %) critical to populations due to life history characteristics
• Previous off-site translocation studies
MethodsStudy Animals
• 98 telemetered turtles in 3 groups starting in 2008 and 7 natives added in 2009
– 33 off-site
– 32 on-site
– 40 native
Timeline of mortalities
•2008: Shells of incidental natives• None sent for necropsy
•2009: Two turtles necropsied • Both attributed to a Ranavirus
•2010: Three turtles necropsied• One presumptive Ranavirus
–Wetland surveilance•Lithobates sylvatica and Ambystoma sp. Apparent 100% die off comfirmed Ranavirus
•2011 -- Seven turtles necropsied• All positive•Amphibians apparent 100% die off, none necropsied
Total Mortalities
• Wood Frog 2 years reproduction (1000’s)
• Salamander 2 years reproduction (100’s)
• Turtle 27 Telemetered 40+ Unmarked
Yearly Survival Estimates
Relocation Year Survival SEOn-Site 1 0.839 0.066On-Site 2 0.913 0.059On-Site 3 0.905 0.064On-Site 4 0.750 0.153Off-Site 1 0.938 0.043Off-Site 2 0.870 0.070Off-Site 3 0.842 0.084Off-Site 4 0.833 0.152Native 1 0.971 0.029Native 2 0.828 0.070Native 3 0.900 0.067Native 4 1.000 0.000Combined 1 0.918 0.028Combined 2 0.867 0.039Combined 3 0.883 0.041Combined 4 0.893 0.058
Where does the road lead from here?
• Understand multi-species (order) dynamics.
• Long term
• Health assessment for any translocation
Acknowledgements
• Maryland State Highway Administration
– Rob Shreeve
• Montgomery County Parks
• Box Turtle Advisory Group
• Sandy Barnett
• David Smith
• Holly Shipley
• USGS Wildlife Health Center
– Dr. David Green
– Dr. Anne Ballmann
• Rich Seigel
• Joel Snodgrass
• Gerald Robinson
• Pat Cain
• Teal Richards
• Nicole Wright
• Allison Allen
• Christine Chun
• Garrett Sisson
• Nathan Byer
• Holly Badin