Are Icelandic harbor seals acoustically cryptic to avoid predation?

Male harbor seals (Phoca vitulina) produce stereotypic underwater roars during the mating season. It remains unclear to what extent roar structures vary due to predation levels. Here, seal roars from waters with many (Iceland) and few (Denmark and Sweden) predators were compared. Most Icelandic roar...

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Bibliographic Details
Published in:JASA Express Letters
Main Authors: Rößler, Helen, Tougaard, Jakob, Sabinsky, Puk Faxe, Rasmussen, Marianne H., Granquist, Sandra M., Wahlberg, Magnus
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
Online Access:https://portal.findresearcher.sdu.dk/da/publications/2cf09263-b502-4f24-a770-8722e4f7640e
https://doi.org/10.1121/10.0003782
https://findresearcher.sdu.dk/ws/files/199510768/10.0003782.pdf
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Summary:Male harbor seals (Phoca vitulina) produce stereotypic underwater roars during the mating season. It remains unclear to what extent roar structures vary due to predation levels. Here, seal roars from waters with many (Iceland) and few (Denmark and Sweden) predators were compared. Most Icelandic roars included a long pulse train and a pause. Icelandic roars occurred less frequently, lasted longer (20.3 ± 6.5 s), and were recorded with lower received sound levels (98.3 ± 8.9 dB re 1 μPa root mean square) than roars from Denmark and Sweden. Local extrinsic factors may shape sound production in harbor seals more than previously reported.