01876nas a2200193   4500008004100000245012500041210006900166520117200235653003101407653002001438653001901458653001801477100002901495700002601524700002701550700001901577700002001596856006601616       2021                        eng d00aLimited vocal compensation for elevated ambient noise in bearded seals: implications for an industrializing Arctic Ocean0 aLimited vocal compensation for elevated ambient noise in bearded3 a<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>
10abearded seal advertisement10achanging Arctic10aLombard effect10anoise impacts1 aFournet, Michelle, E. H.1 aSilvestri, Margherita1 aClark, Christopher, W.1 aKlinck, Holger1 aRice, Aaron, N.  uhttps://royalsocietypublishing.org/doi/10.1098/rspb.2020.271201996nas a2200265   4500008004100000022001400041245007900055210006900134260002000203300001300223490000700236520110200243653002701345653002401372653002301396653002301419100001701442700002701459700002201486700001701508700002301525700002001548700001801568856014401586       2018                        eng d  a1744-956100aDolphins simplify their vocal calls in response to increased ambient noise0 aDolphins simplify their vocal calls in response to increased amb  cSep-05-20182022  a201804840 v143 a<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>
10aacoustic communication10aanthropogenic noise10abottlenose dolphin10avocal modification1 aFouda, Leila1 aWingfield, Jessica, E.1 aFandel, Amber, D.1 aGarrod, Aran1 aHodge, Kristin, B.1 aRice, Aaron, N.1 aBailey, Helen  uhttp://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2018.0484https://syndication.highwire.org/content/doi/10.1098/rsbl.2018.0484