Connectivity of natural areas through biological corridors is essential for ecosystem resilience and biodiversity conservation. However, robust assessments of biodiversity in corridor areas are often hindered by logistical constraints and the statistical challenges of modeling data from multiple species. Herein, we used a hierarchical community occupancy model in a Bayesian framework to evaluate the status of medium and large-sized mammals in a critical link of the Mesoamerican Biological Corridor (MBC) in Costa Rica. We used camera traps deployed from 2013–2017 to detect 18 medium (1–15 kg) and 6 large (>15 kg) mammal species in a portion of two Jaguar Conservation Units (JCUs) and the Corridor linking them. Camera traps operated for 16,904 trap nights across 209 stations, covering an area of 880 km2. Forest cover was the most important driver of medium and large-sized mammal habitat use, with forest specialists such as jaguars (Panthera onca) and pumas (Puma concolor) strongly associated with high forest cover, while habitat generalists such as coyotes (Canis latrans) and raccoons (Procyon lotor) were associated with low forest cover. Medium and large-sized mammal species richness was lower in the Corridor area (x¯ = 9.78±1.84) than in the portions evaluated of the two JCUs (x¯ = 11.50±1.52). Puma and jaguar habitat use probabilities were strongly correlated with large prey species richness (jaguar, r = 0.59, p<0.001; puma, r = 0.72, p<0.001), and correlated to a lesser extent with medium prey species richness (jaguar, r = 0.36, p = 0.003; puma, r = 0.23, p = 0.064). Low estimated jaguar habitat use probability in one JCU (Central Volcanic Cordillera: x¯ = 0.15±0.11) suggests that this is not the jaguar stronghold previously assumed. In addition, the western half of the Corridor has low richness of large mammals, making it necessary to take urgent actions to secure habitat connectivity for mammal populations.

Understanding species-environment relationships at large spatial scales is required for the prioritization of conservation areas and the preservation of landscape connectivity for large carnivores. This endeavour is challenging for jaguars (Panthera onca), given their elusiveness, and the local nature of most jaguar studies, precluding extrapolation to larger areas. We developed an occupancy model using occurrence data of jaguars across five countries of Central America, collected from camera-trap studies of 2-12 months' duration, deployed over an area of 14 112 km 2 from 2005 to 2018. Our occupancy model showed that habitat use of jaguars increased with primary net productivity and distance to human settlements, and decreased with distance to rivers. Detection of the species was related to survey effort and research team identity. Within the jaguar extent of occurrence, 73% was deemed suitable for the species, with 47% of it lying within Jaguar Conservation Units (JCU) and 59% of JCU land being legally protected. Suitable areas were divided into four distinct clusters of continuous habitat shared across country borders. However, large areas of predicted low habitat suitability may constrict connectivity in the region. The reliability of these spatial predictions is indicated by the model validation using an independent dataset (AUC = 0.82; sensitivity = 0.766, specificity = 0.761), and concordance of our results with other studies conducted in the region. Across Central America, we found that human influence has the strongest impact on jaguar habitat use and JCUs are the main reservoirs of habitat. Therefore, conservation actions must focus on preventing habitat loss and mitigating human pressure, particularly within the clusters of continuous areas of high suitability, and on restoring habitat to foster connectivity. The long-term persistence of jaguars in the region will depend on strong international cooperation that secures jaguar populations and their habitat across Central American borders.

La Iniciativa del Corredor del Jaguar pretende mantener la conectividad de esta especie. En Costa Rica, esta iniciativa inició en el Subcorredor Biológico Barbilla-Destierro. En este Subcorredor, se ha identificado la  pavimentación de un camino de lastre (asociado a las obras de mitigación social del Proyecto Hidroeléctrico Reventazón), como una potencial barrera para la conectividad del jaguar (Panthera onca) y otras especies. Este estudio sugiere un método para identificar  los cruces de fauna sobre el camino. Se tomaron datos de junio del 2011 a enero del 2012. Se compararon los registros de avistamientos y atropellos entre una sección de lastre y una de pavimento del mismo camino. Para identificar los pasos de fauna se sobrepusieron distintas fuentes de información: recorridos, entrevistas y conectividad estructural. Al comparar los caminos se encontró que en el pavimento circulan más vehículos, hay más casas, hay más atropellos y se registran menos especies y avistamientos de fauna. Se identificaron tres sitios de cruces de fauna y cinco sectores. Se registró el cruce del camino por jaguar y caucel (Leopardus wiedii) y el uso de una alcantarilla por mapaches (Procyonlotor). Esta metodología puede ser implementada por proyectos viales para identificar los sitios de cruce de fauna y brindar recomendaciones sobre las medidas ambientales de mitigación a implementar asociadas a mejoras o construcción de caminos.