North American river otter habitat suitability and human–wildlife coexistence on Protection Island, British Columbia, Canada

Abstract

Land use change and urban sprawl increase the likelihood of encounters between humans and wildlife. North American river otters (Lontra canadensis) coexist (and also conflict) with humans in many places, including on Protection Island, British Columbia, Canada. River otters are sensitive to, yet also inhabit, environments with relatively high levels of anthropogenic disturbance. From June to November 2022, we investigated the effect of anthropogenic factors on river otter use of space and behavior. We modeled the relative importance of anthropogenic (e.g., distance to buildings and roads, level of human use of docks), environmental (e.g., land cover type), and topographic (elevation) variables for habitat suitability in wild river otters on Protection Island using maximum entropy (MaxEnt) species distribution models, from 660 occurrence points collected. We conducted 178 behavioral scan samples (containing 594 observations) from direct-observation video and motion-triggered trail camera video to evaluate behavioral differences associated with the use of an anthropogenic habitat feature, docks (a potential attractant), and land. We found that the most suitable areas for river otters in this study were near docks (at all levels of human use), near water or wetlands (within ~25 m of the water), and had intermediate densities of driftwood. Further, our findings indicated that human activities generally did not impede otter use of space — river otters and humans were able to coexist in this semi-urban context. Behaviors on docks differed from behaviors on land, and river otters used docks more than would be expected by chance overall, and specifically overnight, and used docks for individual and social activities. Our case study suggests that anthropogenic and environmental factors are key habitat suitability predictors for river otters, and that in populations habituated to human presence, docks may act as a habitat attractant. This case can inform conservation and management practices for river otters, other flagship species, and the ecosystems they inhabit, enhancing human–wildlife coexistence in anthropogenic landscapes.