The Use of Arboreal Wildlife Bridges by Neotropical Mammals Increases Markedly With Time Since Deployment and Varies by Design

Roads and other linear infrastructure have detrimental impacts on wildlife populations, by fragmenting habitat, disrupting wildlife movement, and killing wildlife via collisions. Such alterations are particularly concerning for arboreal mammals, as they have been identified as disproportionately impacted by linear infrastructure relative to their terrestrial counterparts. One way to mitigate the negative effects of linear infrastructure for arboreal wildlife is to install “arboreal bridges”—structures which facilitate the movement of animals without the need for them to come to the ground. However, our understanding of the effectiveness of different arboreal bridge designs (e.g., length, bridge construction materials) remains sparse, particularly for the Neotropics, potentially limiting the effectiveness of conservation interventions. We installed 17 arboreal bridges over roads using five different designs, then evaluated their effectiveness in facilitating arboreal mammal movement using camera traps. We modeled crossing frequency as a function of bridge length, bridge height, design, local canopy cover, and time since installation. From December 2020 to June 2023, we recorded 2231 crossing events by more than 13 mammal species, including endemic, threatened, and known roadkill‐affected species. Our findings reveal that bridge length and duration since installation were the strongest positive predictors of crossing activity, while denser local canopy cover negatively affected usage. Rope‐based designs outperformed ladder bridges in both crossing frequency and species richness. Notably, bridge use increased consistently over a 30‐month period, underscoring the importance of long‐term monitoring to capture true conservation impact. These findings enhance our understanding of the use of arboreal bridges by mammals and can guide the selection of the most effective bridge design for future installations across the Neotropics.