Is vertebrate mortality correlated to potential permeability by underpasses along low-traffic roads?

  • Published source details Delgado J.D., Morelli F., Arroyo N.L., Duran J., Rodriguez A., Rosal A., del Valle Palenzuela M. & Rodríguez J.D.G.P. (2018) Is vertebrate mortality correlated to potential permeability by underpasses along low-traffic roads?. Journal of Environmental Management, 221, 53-62.


This study is summarised as evidence for the following.

Action Category

Install tunnels/culverts/underpasses under roads/railways

Action Link
Reptile Conservation
  1. Install tunnels/culverts/underpasses under roads/railways

    A replicated study in 2009–2010 in mixed oak woodland and shrubland in west Andalusia, Spain (Delgado et al. 2018) found that higher numbers and density of underpasses did not reduce numbers of reptile road casualties. Data were reported as statistical model outputs. Spatial distribution of underpasses was not associated with patterns of reptile road casualties, which were found on average 100 m from the nearest underpass. In total 55 reptile carcasses were found (0.1–2.6 reptiles/km). Four roads were surveyed (53 km in total) for reptile carcasses on foot by 1–4 observers during October 2009–January 2010 and April–July 2010 (30 days surveying in total). Each road was surveyed twice. Underpasses were existing culverts or other road drainage tunnels.

    (Summarised by: Katie Sainsbury)

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