EFFECT OF ROAD TRAFFIC ON AMPHIBIAN DENSITY

We studied the effect of traffic intensity on local abundance of anura ns. We counted dead and live frogs and toads per km and estimated frog and toad local abundances using breeding chorus intensities on simila r roads through similar habitats, but with different levels of traffic intensity. After correcting for effects of date, local habitat, time, and region, our analyses demonstrated that (I) the number of dead and live frogs and toads per km decreased with increasing traffic intensi ty; (2) the proportion of frogs and toads dead increased with increasi ng traffic intensity; and (3) the frog and toad density, as measured b y the chorus intensity, decreased with increasing traffic intensity. T aken together, our results indicate that traffic mortality has a signi ficant negative effect on the local density of anurans. Our results su ggest that recent increases in traffic volumes worldwide are probably contributing to declines in amphibian populations, particularly in pop ulated areas.