@article {58417,
	title = {Limited vocal compensation for elevated ambient noise in bearded seals: implications for an industrializing Arctic Ocean},
	year = {2021},
	abstract = {<p>Vocalizing animals have several strategies to compensate for elevated ambient noise. These behaviours evolved under historical conditions, but compensation limits are quickly being reached in the Anthropocene. Acoustic communication is essential to male bearded seals that vocalize for courtship and defending territories. As Arctic sea ice declines, industrial activities and associated anthropogenic noise are likely to increase. Documenting how seals respond to noise and identifying naturally occurring behavioural thresholds would indicate either their resilience or vulnerability to changing soundscapes. We investigated whether male bearded seals modified call amplitudes in response to changing ambient noise levels. Vocalizing seals increased their call amplitudes until ambient noise levels reached an observable threshold, above which call source levels stopped increasing. The presence of a threshold indicates limited noise compensation for seals, which still renders them vulnerable to acoustic masking of vocal signals. This behavioural threshold and response to noise is critical for developing management plans for an industrializing Arctic.</p>
},
	keywords = {bearded seal advertisement, changing Arctic, Lombard effect, noise impacts},
	doi = {10.1098/rspb.2020.2712},
	url = {https://royalsocietypublishing.org/doi/10.1098/rspb.2020.2712},
	author = {Fournet, Michelle E. H. and Silvestri, Margherita and Clark, Christopher W. and Klinck, Holger and Rice, Aaron N.}
}
@article {53324,
	title = {Dolphins simplify their vocal calls in response to increased ambient noise},
	journal = {Biology Letters},
	volume = {14},
	year = {2018},
	month = {Sep-05-20182022},
	pages = {20180484},
	abstract = {<p>Ocean noise varies spatially and temporally and is driven by natural and anthropogenic processes. Increased ambient noise levels can cause signal masking and communication impairment, affecting fitness and recruitment success. However, the effects of increasing ambient noise levels on marine species, such as marine mammals that primarily rely on sound for communication, are not well understood. We investigated the effects of concurrent ambient noise levels on social whistle calls produced by bottlenose dolphins (Tursiops truncatus) in the western North Atlantic. Elevated ambient noise levels were mainly caused by ship noise. Increases in ship noise, both within and below the dolphins\&$\#$39; call bandwidth, resulted in higher dolphin whistle frequencies and a reduction in whistle contour complexity, an acoustic feature associated with individual identification. Consequently, the noise-induced simplification of dolphin whistles may reduce the information content in these acoustic signals and decrease effective communication, parent\&ndash;offspring proximity or group cohesion.</p>
},
	keywords = {acoustic communication, anthropogenic noise, bottlenose dolphin, vocal modification},
	issn = {1744-9561},
	doi = {10.1098/rsbl.2018.0484},
	url = {http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2018.0484https://syndication.highwire.org/content/doi/10.1098/rsbl.2018.0484},
	author = {Fouda, Leila and Wingfield, Jessica E. and Fandel, Amber D. and Garrod, Aran and Hodge, Kristin B. and Rice, Aaron N. and Bailey, Helen}
}
