Modeling road mortality hotspots of Eastern Hermann’s tortoise in Romania

in Amphibia-Reptilia
Restricted Access
Get Access to Full Text
Rent on DeepDyve

Have an Access Token?

Enter your access token to activate and access content online.

Please login and go to your personal user account to enter your access token.


Have Institutional Access?

Access content through your institution. Any other coaching guidance?


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.

Modeling road mortality hotspots of Eastern Hermann’s tortoise in Romania

in Amphibia-Reptilia



  • AndrewsK.M.GibbonsJ.W. (2005): How do highways influence snake movement behavioral responses to roads and vehicles? Copeia 4: 772-782.

  • AndrewsK.M.GibbonsJ.W.JochimsenD.M. (2008): Ecological effects of roads on amphibians and reptiles: a literature review. In: Urban Herpetology. MitchellJ.C.Jung BrownR.E.BartholomewB.E. Eds Herpetol. Conserv. 3: 121-143.

  • AshleyJ.P.RobinsonJ.T. (1996): Road mortality of amphibians, reptiles and other wildlife on the Long Point Causeway, Lake Erie, Ontario. Can. Field-Natur. 110: 403-412.

  • AshleyJ.P.KosloskiA.PetrieS.A. (2007): Incidence of intentional vehicle-reptile collisions. Hum. Dimens. Wildl. 12: 137-143.

  • BartumeusF.Da LuzM.G.E.ViswanathanG.M.CatalanJ. (2005): Animal search strategies: A quantitative random-walk analysis. Ecol. 86: 3078-3087.

  • BeaudryF.deMaynadierP.G.HunterM.L.Jr. (2008): Identifying road mortality threat at multiple spatial scales for semi-aquatic turtles. Biol. Conserv. 141: 2550-2563.

  • BeaudryF.deMaynadierP.G.HunterM.L.Jr. (2010): Identifying hot moments in road-mortality risk for freshwater turtles. J. Wildl. Manag. 74(1): 152-159.

  • BertoleroA.CheylanM.HaileyA.LivoreilB.WillemsenR.E. (2011): Testudo hermanni (Gmelin 1789) – Hermann’s Tortoise. Chelonian Research Monographs: Chelonian Research Foundation.

  • BeyerH.L. (2011): Geospatial Modelling Environment (version 0.5.3 Beta). (software). URL:

  • BonardiA.ManentiR.CorbettaA.FerriV.FiacchiniD.GiovineG.MacchiS.RomanazziE.SocciniC.BottoniL.Padoa-SchioppaE.FicetolaG.F. (2011): Usefulness of volunteer data to measure the large scale decline of “common” toad populations. Biol. Conserv. 144: 2328-2334.

  • BowneD.R.BowersM.A.HinesJ.E. (2006): Connectivity in an agricultural landscape as reflected by interpond movements of a freshwater turtle. Conserv. Biol. 20: 780-791.

  • BrzezińskiM.EliavaG.ŻmihorskiM. (2012): Road mortality of pond-breeding amphibians during spring migrations in the Mazurian Lakeland, NE Poland. Eur. J. Wildl. Res. 58: 685-693.

  • ByersJ.A. (2001): Correlated random walk equations of animal dispersal resolved by simulation. Ecol. 82: 1680-1690.

  • CamponelliK.M.CaseyR.E.SnodgrassJ.W.LevS.M.LandaE.R. (2009): Impacts of weathered tire debris on the development of Rana sylvatica larvae. Chemosphere 74: 717-722.

  • ChaineyS. (2010): Spatial significance hotspot mapping using the Gi* statistic. 21st Annual Problem-Oriented Policing Conference. Available from (accesed July 2012).

  • ClaussenD.L.LimR.KurzM.WrenK. (2002): Effects of slope, substrate, and temperature on the locomotion of the Ornate Box Turtle, Terrapene ornata. Copeia 2: 411-418.

  • ClaussenD.L.SnashallJ.BardenC. (2004): 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: 269-276.

  • ClevengerA.P.WierzchowskiJ.ChruszczB.GunsonK. (2002): GIS-generated, expert-based models for identifying wildlife habitat linkages and planning mitigation passages. Conserv. Biol. 16: 503-514.

  • CoffinA.W. (2007): From roadkill to road ecology: A review of the ecological effects of roads. J. Transp. Geograph. 15: 396-406.

  • 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.

  • CuretonJ.C.DeatonR. (2012): Hot moments and hot spots: Identifying factors explaining temporal and spatial variation in turtle road mortality. J. Wildl. Manag. 76: 1047-1052.

  • CushmanS.A. (2006): Effects of habitat loss and fragmentation on amphibians: A review and prospectus. Biol. Conserv. 128: 231-240.

  • deMaynadierP.G.HunterM.L.Jr. (2000): Road effects on amphibian movements in a forested landscape. Nat. Areas J. 20: 56-65.

  • DoddC.K.BarichivichW.J.SmithL.L. (2004): Effectiveness of a barrier wall and culverts in reducing wildlife mortality on a heavily traveled highway in Florida. Biol. Conser. 118: 619-631.

  • ESRI (2009): ArcGIS Desktop 9.3 Help. Hot Spot Analysis (Getis-Ord Gi*) (Spatial Statistics). Available from*)_(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.

  • ForbesC.EvansM.HastingsN.PeacockB. (2010): Exponential distribution. In: Statistical Distributions p.  88-92. John Wiley & Sons, Inc.

  • FormanR.T.T.SperlingD.BissonetteJ.A.ClevengerA.P.CutshallC.D.DaleV.H.FahrigL.FranceR.GoldmanC.R.HeanueK.JonesJ.A.SwansonF.J.TurrentineT.WinterT.C. (2003): 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.

  • FrairJ.L.MerrillE.H.BeyerH.L.MoralesJ.M. (2008): Thresholds in landscape connectivity and mortality risks in response to growing road networks. J. Appl. Ecol. 45: 1504-1513.

  • GibbsJ.P.ShriverW.G. (2002): Estimating the effects of road mortality on turtle populations. Conserv. Biol. 16: 1647-1652.

  • GibbsJ.P.ShriverW.G. (2005): Can road mortality limit populations of pool-breeding amphibians? Wetl. Ecol. Manag. 13: 281-289.

  • GlistaD.J.DeVaultT.L.DeWoodyJ.A. (2009): A review of mitigation measures for reducing wildlife mortality on roadways. Landsc. Urban Plan 91: 1-7.

  • GooleyA.C. (2010): Testing the behavioral responses of West Virginia Turtles to roads and vehicles. Dissertation Marshall University.

  • GuyotG.ClobertJ. (1997): Conservation measures for a population of Hermann’s tortoise Testudo hermanni in southern France bisected by a major highway. Biol. Conserv. 79: 251-256.

  • GunsonK.E.ClevengerA.P.FordA.T.BissonetteJ.A.HardyA. (2009a): A comparison of data sets varying in spatial accuracy used to predict the occurrence of wildlife-vehicle collisions. Environ. Manag. 44: 268-277.

  • 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.

  • GunsonK.E.MountrakisG.QuackenbushL.J. (2011): Spatial wildlife-vehicle collision models: A review of current work and its application to transportation mitigation projects. J. Environ. Manag. 92: 1074-1082.

  • HartelT.MogaC.I.OllererK.PukyM. (2009): 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: 130-141.

  • HelsT.BuchwaldE. (2001): The effect of road kills on amphibian populations. Biol. Conserv. 99: 331-340.

  • HitchingsS.P.BeebeeT.J.C. (1997): Genetic substructuring as a result of barriers to gene flow in urban Rana temporaria (common frog) populations: implications for biodiversity conservation. Heredity 79: 117-127.

  • HothornT.BrandlR.MüllerJ. (2012): Large-scale model-based assessment of deer-vehicle collision risk. PLoS ONE 7: 1-10.

  • IojăC.I.PătroescuM.RozylowiczL.PopescuV.D.VergheleţM.ZottaM.I.FelciucM. (2010): The efficacy of Romania’s protected areas network in conserving biodiversity. Biol. Conserv. 143: 2468-2476.

  • JolyP.MorandC.CohasA. (2003): Habitat fragmentation and amphibian conservation: building a tool for assessing landscape matrix connectivity. C. R. Biol. 326: 132-139.

  • KarrakerN.E.GibbsJ.P.VoneshJ.R. (2008): Impacts of road deicing salt on the demography of vernal pool-breeding amphibians. Ecol. Appl. 18: 724-734.

  • KarrakerN.E.RuthigG.R. (2009): Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds. Environ. Res. 109: 40-45.

  • LangenT.A.OgdenK.M.SchwartingL.L. (2009): Predicting hot spots of herpetofauna road mortality along highway networks. J. Wildl. Manag. 73: 104-114.

  • LovichJ.E.EnnenJ.R.MadrakS.GroverB. (2011): Turtles and culverts, and alternative energy development: An unreported but potentially significant mortality threat to the Desert Tortoise (Gopherus agassizii). Chelonian Conserv. Biol. 10: 124-129.

  • MazzotiS.PisapiaA.FasolaM. (2002): Activity and home range of Testudo hermanni in Northern Italy. Amphibia-Reptilia 23: 305-312.

  • McCollisterM.F.Van ManenF.T. (2010): Effectiveness of wildlife underpasses and fencing to reduce wildlife-vehicle collisions. J. Wildl. Manag. 74: 1722-1731.

  • MeekR. (2009): Patterns of reptile road-kills in the Vendee region of western France. Herpetol. J. 19: 135-142.

  • MountrakisG.GunsonK. (2009): Multi-scale spatiotemporal analyses of moose-vehicle collisions: a case study in northern Vermont. Int. J. Geograph. Inf. Sci. 23: 1389-1412.

  • MuegelL.A.ClaussenD.L. (1994): Effects of slope on voluntary locomotor performance in the turtle, Terrapene carolina carolina. J. Herpetol. 28: 6-11.

  • OrdJ.K.GetisA. (1995): Local spatial autocorrelation statistics: distributional issues and an application. Geograph. Anal. 27: 286-306.

  • PatrickD.A.GibbsJ.P.PopescuV.D.NelsonD.A. (2012): Multi-scale habitat-resistance models for predicting road mortality “hotspots” for reptiles and amphibians. Herpetol. Conserv. Biol. 7(3): 407-426.

  • PatrickD.A.SchalkC.GibbsJ.P.WoltzH. (2010): Effective culvert placement and design to facilitate passage of amphibians across roads. J. Herpetol. 44: 618-626.

  • 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 Accessed 07 September 2012.

  • RayN.LehmannA.JolyP. (2002): Modeling spatial distribution of amphibian populations: a GIS approach based on habitat matrix permeability. Biodivers. Conserv. 11: 2143-2165.

  • RoeJ.H.GibsonJ.KingsburyB.A. (2006): Beyond the wetland border: estimating the impact of roads for two species of water snakes. Biol. Conserv. 130: 161-168.

  • Romanian National Company of Highways and National Roads (2010): General census of traffic intensity. Romanian National Company of Highways and National Roads Bucharest.

  • RozylowiczL.DobreM. (2010): Assessing the threatened status of Testudo hermanni boettgeri Mojsisovics, 1889 (Reptilia: Testudines: Testudinidae) population from Romania. North-Western J. Zool. 6: 190-202.

  • RozylowiczL.PătroescuM. (2004): Dimorfismul sexual la ţestoasa lui Hermann (Testudo hermanni boettgeri Mojsisovics 1889) din Parcul Natural Porţile de Fier. Drobeta Seria Ştiinţele Naturii 14: 42-49.

  • RozylowiczL.PopescuV.D. (2013): Habitat selection and movement ecology of Eastern Hermann’s tortoises in a rural Romanian landscape. Eur. J. Wildl. Res. 59: 47-55.

  • RugieroL.LuiselliL. (2006): Ecological modelling of habitat use and the annual activity patterns in an urban population of the tortoise, Testudo hermanni. Ital. J. Zool. 73: 219-225.

  • ShepardD.B.KuhnsA.R.DreslikM.J.PhillipsC.A. (2008): Roads as barriers to animal movement in fragmented landscapes. Anim. Conserv. 11: 288-296.

  • SteenD.A.GibbsJ.P. (2004): Effects of roads on the structure of freshwater turtle populations. Conserv. Biol. 18: 1143-1148.

  • SteenD.A.ArescoM.J.BeilkeS.G.ComptonB.W.CondonE.P.KennethD.C.ForresterH.GibbonsJ.W.GreeneJ.L.JohnsonG.LangenT.A.OldhamM.J.OxierD.N.SaumureR.A.SchuelerF.W.SleemanJ.M.SmithL.L.TuckerJ.K.GibbsJ.P. (2006): Relative vulnerability of female turtles to road mortality. Anim. Conserv. 9: 269-273.

  • TrombulakaS.C.FrissellC.A. (2000): Review of ecological effects of roads on terrestrial and aquatic communities. Conserv. Biol. 14: 18-30.

  • WederkinchE. (1988): Population size, migration barriers and other features of Rana dalmatina populations near Koge, Zealand, Denmark. Mem. Soc. Fauna Flora Fenn. 64: 101-103.

  • WrenK.ClaussenD.L.KurzM. (1998): The effects of body size and extrinsic mass on the locomotion of the Ornate Box Turtle, Terrapene ornata. J. Herpetol. 32: 144-150.

  • YanesM.VelascoJ.M.SuárezF. (1995): Permeability of roads and railways to vertebrates: The importance of culverts. Biol. Conserv. 71: 217-222.


  • View in gallery

    Road mortality hotspots for Hermann’s tortoise in Romania. Thicker lines are roads with higher vehicle traffic and higher tortoise mortality. Hotspots of road mortality for Hermann’s tortoises in Romania are indicated by darker grid cells. The map highlights the sites with mortality rates significantly higher than expected (Getis Ord Statistic Zscores1.96). The hotspot model ignores the areas with no roads or documented occurrences where no road mortality may occur (N.A. values).

  • View in gallery

    Gender-specific differences in probability of being killed on roads for Eastern Hermann’s tortoise, estimated from an equation derived by Hels and Buchwald (2001). The shaded area represents the predictions within the range of empirically-determined tortoise velocities: 0.96-7.64 m/minute.

Index Card

Content Metrics

Content Metrics

All Time Past Year Past 30 Days
Abstract Views 85 85 15
Full Text Views 128 128 0
PDF Downloads 7 7 0
EPUB Downloads 0 0 0