Trunks and treetops: integrating terrestrial and arboreal camera-trap surveys to document elusive mammal communities in India
|Trunks and treetops: integrating terrestrial and arboreal camera-trap surveys to document elusive mammal communities in India
|Year of Publication
|Nazareth O, Srivathsa A, Ramachandran V
Tropical rainforest canopies harbor nearly half of the world's biodiversity. Previous research on rainforest ecosystems has primarily focused on the terrestrial stratum, leading to a limited understanding of forest canopies. Camera traps have seen a wide application in the studies of terrestrial mammals, but their utility for documenting arboreal mammal communities has been far more limited. Financial resources, field training, and access to equipment and logistical constraints may have precluded researchers from undertaking systematic arboreal camera surveys, especially in the Global South countries. We deployed arboreal and terrestrial cameras to document the mammal assemblage in Kadumane estate, Western Ghats, India. During April-May 2022, we documented 3 exclusively arboreal, 11 semi-arboreal and 14 terrestrial species, using 16 cameras in the canopies and 13 cameras on the ground. Using rarefaction curves, we find that 648 trap-nights were sufficient to document all the arboreal species, while > 1350 trap-nights of additional effort would have been required to document all the terrestrial species in our study site. For each species, we generated an arboreality index (calculated from proportional capture rates) to gauge its propensity for arboreal habits. We also compared the efficacy of using different baits; species responses to shrimp-dry fish baits indicated a reduction in rodent captures when carnivore captures were higher. Our study deliberates on the resources, logistical considerations, and advantages of arboreal camera surveys to study mammal assemblages in forest canopies. Importantly, we highlight the utility of such surveys for understanding the ecology of rare, elusive, and hitherto under-studied species that may be threatened with extinction.