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Southern right whales show no behavioral response to low noise levels from a nearby unmanned aerial vehicle
Author(s) -
Christiansen Fredrik,
Nielsen Mia L. K.,
Charlton Claire,
Bejder Lars,
Madsen Peter T.
Publication year - 2020
Publication title -
marine mammal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.723
H-Index - 78
eISSN - 1748-7692
pISSN - 0824-0469
DOI - 10.1111/mms.12699
Subject(s) - right whale , theodolite , cetacea , aerial survey , environmental science , noise (video) , baleen , altitude (triangle) , whale , oceanography , acoustics , remote sensing , biology , fishery , geography , geology , geodesy , computer science , physics , mathematics , geometry , artificial intelligence , image (mathematics)
Unmanned aerial vehicles (UAVs) are increasingly used for wildlife research and monitoring, but little information exists on their potential effect on marine mammals. We assessed the effects of a UAV on the behavior of southern right whales ( Eubalaena australis ) in Australia. Focal follows of ten right whale mother‐calf pairs were conducted using a theodolite. Control data were recorded for 30 min, and then a DJI Inspire 1 Pro was flown above the whales for 10 min at 5 m altitude. Potential changes to horizontal behavior (swim speed and turning angle) and surfacing pattern (interbreath intervals) were investigated by comparing mother‐calf behavior before and during UAV approaches. Changes in respiration rate were used to quantify energetic effects. We also explored acoustic cue perceptibility of the UAV at 5, 10, and 30 m altitude, by measuring the received UAV underwater noise level on whales equipped with acoustic tags (DTAGs). The received noise levels were 86.0 ± 3.9 dB re 1 μPa, while the measured ambient noise was 80.7 ± 7.3 dB re 1 μPa in the same frequency band (100–1,500 Hz). No behavioral response to the UAV was observed. This provides support for UAVs as a noninvasive tool to study baleen whale behavior and ecophysiology.