Road-associated mortality can lead to local declines of wildlife populations, and management agencies are actively implementing mitigation measures, especially focused on potential road mortality hotspots. In this study we used a spatially-explicit simulation modeling approach to estimate the hotspots of road mortality for the Eastern Hermann’s tortoise (Testudo hermanni boettgeri) within its distribution range in Romania. Using a field experiment, we first evaluated velocities while crossing roads. Adult male tortoises moved faster than females (3.98 m/min vs. 2.51 m/min) which led to higher individual probabilities for females being killed on high-traffic roads (0.61 for females vs. 0.44 for males at traffic levels of 7000 vehicles/day). Both males and females had similar road mortality probabilities for traffic levels <1000 and >35 000 vehicles/day. Our spatially explicit model suggests that, within the entire Romanian distributional range, the tortoises have an overall risk of road mortality 1.6%, which may have a negative impact on tortoise populations. Using the Getis-Ord Gi statistic, we identified road mortality hotspots with mortality rates of 5-30%, in areas bisected by high-traffic national and European-level roads. Our research is timely in that many low-traffic roads are predicted to have increased traffic associated with tourism activities, thus increasing the overall risk of mortality. We suggest that mitigation measures such as signage and roadside fences associated with underpasses have the potential to limit road mortality of this threatened species within predicted current mortality hotspots.
Ecological effects of roads on amphibians and reptiles: a literature review. In:
MitchellJ.C.Jung BrownR.E.BartholomewB.E. Eds Herpetol. Conserv. 3:
Usefulness of volunteer data to measure the large scale decline of “common” toad populations.
ChaineyS. (2010): Spatial significance hotspot mapping using the Gi* statistic. 21st Annual Problem-Oriented Policing Conference. Available from http://www.popcenter.org/conference/conferencepapers/2010/Chainey-Gi-hotSpots.pdf (accesed July 2012).
Effects of slope, substrate, and temperature on the locomotion of the Ornate Box Turtle, Terrapene ornata.
Effects of slope, substrate, and temperature on forces associated with locomotion of the ornate box turtle, Terrapene ornata.
Comp. Biochem. Physiol. A Mol. Integr. Physiol.138:
Council Directive 2006/105/EC of 20 November 2006 adapting Directives 73/239/EEC 74/557/EEC and 2002/83/EC in the field of environment by reason of the accession of Bulgaria and Romania. Official Journal L 363 20/12/2006.
Hot moments and hot spots: Identifying factors explaining temporal and spatial variation in turtle road mortality.
J. Wildl. Manag.76:
ESRI (2009): ArcGIS Desktop 9.3 Help. Hot Spot Analysis (Getis-Ord Gi*) (Spatial Statistics). Available from http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Hot_Spot_Analysis_(Getis-Ord_Gi*)_(Spatial_Statistics). Accessed 10 July 2012.
FestinS.M. (1996): Summary of national and regional travel trends: 1970-1995. Office of Highway Information Management Federal Highway Administration Washington DC.
Exponential distribution. In:
Statistical Distributions p.
88-92. John Wiley & Sons, Inc.
Road Ecology: Science and Solutions. Island PressWashington, D.C. In.
FrairJ.L. (2005): Survival and movement behaviour of resident and translocated Wapiti (Cervus elaphus): implications for their management in West-central Alberta Canada. Dissertation University of Alberta.
Thresholds in landscape connectivity and mortality risks in response to growing road networks.
J. Appl. Ecol.45:
A comparison of data sets varying in spatial accuracy used to predict the occurrence of wildlife-vehicle collisions.
GunsonK.E.IrelandD.ScheulerF. (2009b): Incorporating road-mortality hotspot modeling and connectivity analyses into road mitigation planning in Ontario. International Conference on Ecology and Transportation; Duluth Minnesota.
Spatial wildlife-vehicle collision models: A review of current work and its application to transportation mitigation projects.
J. Environ. Manag.92:
Spatial and temporal distribution of amphibian road mortality with a Rana dalmatina and Bufo bufo predominance along the middle section of the Tarnava Mare basin, Romania.
North-West J. Zool.5:
Genetic substructuring as a result of barriers to gene flow in urban Rana temporaria (common frog) populations: implications for biodiversity conservation.
Turtles and culverts, and alternative energy development: An unreported but potentially significant mortality threat to the Desert Tortoise (Gopherus agassizii).
Chelonian Conserv. Biol.10:
PukyM.FarkasJ.RonkayM.T. (2007): Use of existing mitigation measures by amphibians reptiles and small to medium-size mammals in Hungary: Crossing structures can function as multiple species-oriented measures. UC Davis: Road Ecology Center http://escholarship.org/uc/item/991742nk. Accessed 07 September 2012.
Modeling spatial distribution of amphibian populations: a GIS approach based on habitat matrix permeability.
Romanian National Company of Highways and National Roads (2010): General census of traffic intensity. Romanian National Company of Highways and National Roads Bucharest.
Assessing the threatened status of Testudo hermanni boettgeri Mojsisovics, 1889 (Reptilia: Testudines: Testudinidae) population from Romania.
North-Western J. Zool.6: