The effect of roads and traffic on hedgehog (Erinaceus europaeus) populations

We studied the effect of roads and traffic on hedgehog population density by comparing relative densities in 15 paired road and control plots matched for landscape parameters. Relative hedgehog density was determined by means of footprints in specially designed tunnels. The relative density was closely correlated with the total number of individual hedgehogs that were caught in traps in five of the plots immediately after the tunnels were removed. A power analysis indicated that, with the resources available, we could only detect an effect greater than 35%. We were unable to demonstrate a significant effect, i.e. hedgehog density in areas adjacent to roads is not reduced by more than 35%. However, we did find about 30% fewer tracks in road plots when compared to control plots and the P-values were marginally insignificant at the Pless-than-or-equals, slant0.05 significance level. These results suggest that roads and traffic are likely to reduce hedgehog density by about 30%, which may affect the survival probability of local populations.