[MARMAM] New publication on humpback whale response to noise

[Elisa Maria Girola]

Dear Colleagues,



We are happy to announce the publication of our new paper



Girola E, Dunlop RA, Noad MJ. 2023 Singing humpback whales respond to wind 
noise, but not to vessel noise. Proc. R. Soc. B 290: 20230204. 
https://doi.org/10.1098/rspb.2023.0204



Abstract
Animal communication systems evolved in the presence of noise generated by 
natural sources. Many species can increase the source levels of their sounds to 
maintain effective communication in elevated noise conditions, i.e. they have a 
Lombard response. Human activities generate additional noise in the environment 
creating further challenges for these animals. Male humpback whales are known 
to adjust the source levels of their songs in response to wind noise, which 
although variable is always present in the ocean. Our study investigated 
whether this Lombard response increases when singing males are exposed to 
additional noise generated by motor vessels. Humpback whale singers were 
recorded off eastern Australia using a fixed hydrophone array. The source 
levels of the songs produced while the singers were exposed to varying levels 
of wind noise and vessel noise were measured. Our results show that, even when 
vessel noise is dominant, singing males still adjust the source levels of their 
songs to compensate for the underlying wind noise, and do not further increase 
their source levels to compensate for the additional noise produced by the 
vessel. Understanding humpback whales' response to noise is important for 
developing mitigation policies for anthropogenic activities at sea.





The paper can be accessed here https://doi.org/10.1098/rspb.2023.0204



or you can request a pdf copy from the corresponding author 
(e.gir...@uq.edu.au).

Best regards

Elisa

Dr. Elisa Girola
The University of Queensland
Australia
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] New publication on humpback whale response to noise

[Elisa Maria Girola]

Dear Colleagues,



We are happy to announce the publication of our new paper



Girola, E., Dunlop, R. A., Noad, M. J. (2022). "Singing in a noisy ocean: vocal 
plasticity in male humpback whales." Bioacoustics: 1-24. DOI: 
10.1080/09524622.2022.2122560



Abstract
The songs produced by male humpback whales are believed to be a reproductive 
display shared by all singers within the same population. Ocean noise can 
interfere with the transmission of acoustic signals such as humpback whale 
songs. However, humpback whales evolved in an environment characterised by 
variable levels of noise generated by natural sources. This study investigates 
whether singing males compensate for natural noise by changing the 
characteristics of their sounds.  Songs were recorded off eastern Australia 
during periods of time when the soundscape was dominated by natural noise. 
Source level, peak frequency and duration were measured for 2,318 song units 
from 19 singers. Source levels were positively correlated with noise levels, 
while there was no correlation between the peak frequency or duration of the 
units and noise levels. Our study shows that male humpback whales increase the 
source level of their units in response to increasing natural noise, i.e. they 
have a Lombard response, but they do not modify their spectral or temporal 
characteristics. This suggests that the need to adhere to the shared repertoire 
prevents changes to distinctive features of song units, i.e. frequency and 
duration, however, vocal plasticity allows adjusting source levels to the 
environmental conditions.



The paper can be accessed here https://doi.org/10.1080/09524622.2022.2122560



or you can request a pdf copy from the corresponding author 
(e.gir...@uq.edu.au).

Best regards

Elisa

Dr. Elisa Girola
The University of Queensland
Australia

___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam