Arboreal mammal use of canopy walkway bridges in an Amazonian forest with continuous canopy cover

The Amazon Basin is a biodiversity hotspot, with vertically stratified forests fostering complex habitats and high mammal diversity. Although mammals play a critical role in maintaining ecosystem structure, less is known about arboreal mammal activity and habitat use across forest canopy layers. As forest fragmentation increases, understanding how these changes impact arboreal species is essential for effective conservation efforts. Here, we provide a snapshot of canopy walkway use by arboreal mammals in an Amazonian forest with unfragmented canopy cover, providing insight into their spatial and temporal movement patterns across different canopy layers. This study was conducted at the Amazon Conservatory for Tropical Studies, in the Napo-Sucusari Biological Reserve outside Iquitos, Perú. During a three-week survey, we deployed camera traps at multiple heights along a canopy walkway system to monitor arboreal mammal activity. A total of seven mammal species used this canopy walkway system during our study period. Linnaeus’s two-toed sloth ( Choloepus didactylus ) and the long-tailed porcupine ( Coendou longicaudatus longicaudatus ) were the most commonly observed species, with several observations of the more reclusive and data-deficient C. ichillus also recorded, among other species. Peak activity occurred between 1900 and 2100 h, coinciding with higher temperature and humidity than nighttime averages. Mid-canopy layers (ca. 21 to 27 m above ground) were most frequently used, with decline in use at higher and lower canopy layers. Our findings provide baseline data on arboreal mammal use of canopy walkways in a tropical forest, which may help inform the design of human-created arboreal corridors to connect forest fragments.