Road mortality is a significant cause of otter deaths in Britain, particularly for young animals dispersing to new territories along road-crossed watercourses.
Road mortality causes acute traumatic injury and death to individual otters and represents a significant barrier to population recovery and dispersal. Young male otters in particular, travelling long distances to establish new territories, frequently encounter road crossings. Culverts that flood encourage otters to cross at road level, dramatically increasing collision risk. Retrofitting culverts with otter ledges — simple dry-land passages alongside the water channel — is a cost-effective intervention that reduces mortality at known hotspots. The welfare and conservation benefits of such infrastructure improvements are well-documented.