Heavy traffic, low mortality - tram tracks as terrestrial habitat of newts

Abstract

Amphibian mortality caused by rail traffic has not attracted much attention in comparison to road mortality. Density of railways in landscape, as well as traffic intensity, is usually much lower than in case of roads. As a consequence, their overall effect on amphibian populations is tacitly assumed to be less negative. To test whether very intensive rail traffic can cause substantial mortality in population of a small amphibian, we investigated a Smooth newt Lissotriton vulgaris population located in the city of Poznan, W Poland, where tram tracks border isolated breeding ponds. We performed controls during the peak of autumn migratory activity along the tracks. Less than 1% of all individuals found during the survey were killed by rail traffic. Observed mortality was very low despite large number of individuals present on the track and intensive tram traffic. As negative effects of traffic are low, rail or tram embankments can provide an important terrestrial habitat for small European newts.