Colobus monkeys in East African urban forests face significant road mortality as forest fragmentation forces dangerous road crossings — canopy bridges provide welfare solutions.
Colobus road mortality is a preventable welfare harm arising directly from urban infrastructure decisions. When roads bisect forest patches, arboreal primates face a binary choice: remain in increasingly small fragments or risk road crossing. For colobus — large-bodied, relatively slow-moving arboreal primates — road crossings are extremely dangerous. Rope bridge installations restore canopy connectivity with modest infrastructure investment and documented efficacy. The welfare benefit is direct and immediate: documented bridge use after installation shows that colobus adopt the safer route when it is available. Urban planning that incorporates wildlife connectivity from the design stage — protecting canopy connections across roads — prevents the problem from arising. Retrofitting urban road infrastructure with wildlife crossing structures represents a practical welfare intervention for existing fragmented habitats.