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.2020.2712