Comparison of species richness and detection between line transects, ground camera traps, and arboreal camera traps

Abstract

Monitoring trends in the occurrence of species over time is important for informing conservation plans and concurrent management actions. Understanding the effectiveness of field methodologies for collecting accurate and precise data is crucial for optimizing allocation of sampling effort and resources. In this study, we compared mammalian species richness and detection probabilities between three field methodologies: line transects, ground camera traps and arboreal camera traps in Nyungwe National Park, Rwanda. Arboreal camera traps may be suitable for monitoring mammal communities with arboreal species, but their relative effectiveness compared to the more common field methods, line transects and ground camera traps, is relatively unknown. Using single-season occupancy models with multi-species data and single-species multi-method occupancy models, we estimated mammalian species richness and detection probability for each method and combination of methods. In addition, we estimated single-species occupancy and detection probability by method for six diurnal primate species. And, we tested for the effect of height on a tree on estimated occupancy probability and detection probability for arboreal camera traps. Overall, for all species the combination of ground and arboreal cameras was the most effective methodology in terms of highest estimates of occupancy and detection coupled with highest precision. However, for the six primate species the most effective method differed between species. The height of the arboreal camera trap in the tree did not significantly affect estimates of occupancy or detection. We suggest using all three field methods concurrently to maximize detection of all species; however, if only two methods can be deployed combining arboreal and ground cameras provided the highest and most precise estimates of occupancy and detection. The addition of arboreal camera traps could improve detection of species and improve future species monitoring programs.

Snapshot of the Atlantic Forest canopy: surveying arboreal mammals in a biodiversity hotspot

“…The number of arboreal mammals documented in this study is comparable to species richness reported in different arboreal camera trapping studies conducted in other tropical rainforest sites. In National Parks, Cameroon (Hongo et al, 2020), and 15 arboreal mammals at species level and 2 at genus level in Nyungwe National Park, Rwanda (Moore et al, 2020). Major differences to these studies, in relation to our study, relate to the high species richness of primates found in those habitats, and also squirrel species in Rwanda.…”

“…To date, most of the studies reporting arboreal mammal assemblage in remnants of the Atlantic Forest have been based on ground-based surveys. Our findings demonstrate the potential of arboreal camera trapping to register rare, nocturnal and cryptic species that are prone to false negatives obtained by ground-based methods (Olson et al, 2012;Whitworth et al, 2016;Bowler et al, 2017;Moore et al, 2020). Considering the habits of some scansorial and terrestrial species, we suggest that arboreal camera traps should be paired with terrestrial cameras, which would reduce the likelihood of failing to detect these species.…”

Vertical stratification of seed‐dispersing vertebrate communities and their interactions with plants in tropical forests

“…At the same time, recent technological improvements in monitoring systems now enable the collection of a wide range of ecological data for terrestrial wildlife. For instance, camera traps have proved to be a useful, cost‐effective, and relatively low‐effort technique (Gregory et al ., 2014; Moore et al ., 2020). Furthermore, the development of automated radio‐tracking systems (Gottwald et al ., 2019) will likely allow us to determine the vertical movement patterns even of small animals (see Ripperger et al ., 2020) in the near future and thus will provide an increasingly detailed view of vertical movements of individual animals.…”

Plant–frugivore interactions revealed by arboreal camera trapping

“…2014; Moore et al . 2020), and to date, no studies have used arboreal camera trapping to monitor plant–frugivore networks over an extensive area.…”

“…However, arboreal camera trapping can operate remotely 24 hours a Plant-frugivore interactions revealed by arboreal camera trapping Camera trapping technology -which allows images of organisms to be obtained remotely from the field -has advanced rapidly in recent decades, and its infrared capability has become a standard tool in wildlife monitoring, especially for detecting ground-dwelling endothermic animals (O'Connell et al 2011). However, the activities of animals in arboreal habitats (including the forest canopy) are still poorly known (Gregory et al 2014;Moore et al 2020), and to date, no studies have used arboreal camera trapping to monitor plant-frugivore networks over an extensive area.…”