Southern right whales show no behavioral response to low noise levels from a nearby unmanned aerial vehicle

TY - JOUR

T1 - Southern right whales show no behavioral response to low noise levels from a nearby unmanned aerial vehicle

AU - Christiansen, Fredrik

AU - Nielsen, Mia L.K.

AU - Charlton, Claire

AU - Bejder, Lars

AU - Madsen, Peter T.

PY - 2020

Y1 - 2020

N2 - 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.

AB - 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.

KW - behavioral impact assessment

KW - cetaceans

KW - drones

KW - marine mammals

KW - noise impacts

KW - unmanned aerial systems

UR - http://www.scopus.com/inward/record.url?scp=85084500431&partnerID=8YFLogxK

U2 - 10.1111/mms.12699

DO - 10.1111/mms.12699

M3 - Journal article

AN - SCOPUS:85084500431

SN - 0824-0469

VL - 36

SP - 953

EP - 963

JO - Marine Mammal Science

JF - Marine Mammal Science

IS - 3

ER -