Day and night camera trap videos are effective for identifying individual wild Asian elephants

Sasha Montero-De La Torre; Sarah L Jacobson; Martin Chodorow; Marnoch Yindee; Joshua M Plotnik

doi:10.7717/peerj.15130

Day and night camera trap videos are effective for identifying individual wild Asian elephants

PeerJ. 2023 Mar 28:11:e15130. doi: 10.7717/peerj.15130. eCollection 2023.

Authors

Sasha Montero-De La Torre¹, Sarah L Jacobson^{1

2}, Martin Chodorow^{1

2}, Marnoch Yindee³, Joshua M Plotnik^{1

2}

Affiliations

¹ Department of Psychology, Hunter College, City University of New York, New York, New York, United States.
² Department of Psychology, The Graduate Center, City University of New York, New York, New York, United States.
³ Akkhraratchakumari Veterinary College and One Health Research Centre, Walailak University, Thasala, Nakhon Si Thammarat, Thailand.

Abstract

Regular monitoring of wild animal populations through the collection of behavioral and demographic data is critical for the conservation of endangered species. Identifying individual Asian elephants (Elephas maximus), for example, can contribute to our understanding of their social dynamics and foraging behavior, as well as to human-elephant conflict mitigation strategies that account for the behavior of specific individuals involved in the conflict. Wild elephants can be distinguished using a variety of different morphological traits-e.g., variations in ear and tail morphology, body scars and tumors, and tusk presence, shape, and length-with previous studies identifying elephants via direct observation or photographs taken from vehicles. When elephants live in dense forests like in Thailand, remote sensing photography can be a productive approach to capturing anatomical and behavioral information about local elephant populations. While camera trapping has been used previously to identify elephants, here we present a detailed methodology for systematic, experimenter differentiation of individual elephants using data captured from remote sensing video camera traps. In this study, we used day and night video footage collected remotely in the Salakpra Wildlife Sanctuary in Thailand and identified 24 morphological characteristics that can be used to recognize individual elephants. A total of 34 camera traps were installed within the sanctuary as well as crop fields along its periphery, and 107 Asian elephants were identified: 72 adults, 11 sub-adults, 20 juveniles, and four infants. We predicted that camera traps would provide enough information such that classified morphological traits would aid in reliably identifying the adult individuals with a low probability of misidentification. The results indicated that there were low probabilities of misidentification between adult elephants in the population using camera traps, similar to probabilities obtained by other researchers using handheld cameras. 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.

Keywords: Animal behavior; Asian elephants; Camera trapping; Conservation biology; Human-elephant conflict; Remote-sensing.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Animals
Animals, Wild
Ecosystem
Elephants*
Endangered Species
Forests
Humans

Grants and funding

This work was supported by the US Fish and Wildlife Service Asian Elephant Conservation Fund (F18AP00456; F19AP00052; F22AP00035), the Research Foundation of the City University of New York, Elephant Family (THA-175), the Golden Triangle Asian Elephant Foundation, and a National Science Foundation Graduate Research Fellowship (DGE-1646736) awarded to Sarah L. Jacobson. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.