Camera traps provide a virtual window into the natural world of wild animals, as they provide a noninvasive way to capture anatomical and behavioral information. Regular monitoring of wild populations through the collection of behavioral and demographic data is critical for the conservation of endangered species like the Asian elephant (Elephas maximus). Identifying individual elephants can contribute to our understanding of social dynamics and foraging behavior in this species. Wild elephants can be distinguished using a variety of different morphological traits: variations in ear and tail morphology, body scars and tumors, and tusk presence, shape, and length. However, to our knowledge, there is little explanation in the literature about how remote camera trapping can be used to systematically identify elephants. Thus, this study set out to provide a template for how to provide this information using physical characteristics identified from day and night video footage collected remotely in the Salakpra Wildlife Sanctuary in Thailand between February 2019 and January 2020. We identified 24 morphological characteristics that can be used to identify individual Asian elephants. Using 33 camera traps spread across the protected area within the sanctuary as well as crop fields along its periphery, 107 Asian elephants were identified, for the first time in Thailand, using 475 total day and night videos. In the identified population, there were 72 adults, 11 sub-adults, 20 juveniles, and 4 infants. We predicted that the morphological traits would aid in reliably identifying these individuals with a low probability of misidentification. The results indicated that there were low probabilities of misidentification between elephants in the population using camera traps, and that the elephants in this study were reliably identified. These low probabilities of misidentification are comparable to a previous study using photographic data that were collected through direct observations of wild Asian elephants. This study suggests that the use of day and night video camera trapping can be an important tool for the long-term monitoring of wild Asian elephant behavior, especially in habitats where direct observations may be difficult. This work has important implications for the study of wildlife behavior using remote methods, as well as for endangered species conservation.
Optical design challenges of subnivean camera trapping under extreme Arctic conditions
