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Comparison of aerial thermal infrared imagery and helicopter surveys of bison (Bison bison) in Grand Canyon National Park, USA

July 27, 2021

Aerial thermal infrared (TIR) surveys are an attractive option for estimating abundances of large mammals inhabiting extensive and heterogenous terrain. Compared to standard helicopter or fixed-wing aerial surveys, TIR flights can be conducted at higher altitudes translating into greater spatial coverage and increased observer safety; however, monetary costs are much greater. Further, there is no consensus on whether TIR surveys offer improved detection. Consequently, we per-formed a study to compare results of a TIR and helicopter survey of bison (Bison bison) on the Powell Plateau in Grand Canyon National Park, USA. We also compared results of both surveys to esti-mates obtained using a larger dataset of bison helicopter detections along the entire North Rim of the Grand Canyon. Observers in the TIR survey counted fewer individual bison than helicopter ob-servers (101 to 127) and the TIR survey cost was 367% higher. Additionally, the TIR estimate was 18.8% lower than the estimate obtained using a larger dataset, while the comparative helicopter survey was 9.3% lower. Given the higher raw count, ostensibly more accurate estimates, and lower cost, we propose that helicopter surveys are currently the best choice for estimation and monitoring of bison abundance in Grand Canyon National Park.

Citation Information

Publication Year 2021
Title Comparison of aerial thermal infrared imagery and helicopter surveys of bison (Bison bison) in Grand Canyon National Park, USA
DOI 10.3390/s21155087
Authors Jacob Daniel Hennig, Kathryn A. Schoenecker, Miranda Terwilliger, Gregory W Holm, Jeffrey L. Laake
Publication Type Article
Publication Subtype Journal Article
Series Title Sensors
Index ID 70223296
Record Source USGS Publications Warehouse
USGS Organization Fort Collins Science Center