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| De Ruiter, Stacy; Hansen, Michael; Koopman, Heather N.; Westgate, Andrew J.; Tyack, Peter L.; Madsen, Peter T.. |
| Estimating the range at which harbor porpoises can detect prey items and environmental objects is integral to understanding their biosonar. Understanding the ranges at which they can use echolocation to detect and avoid obstacles is particularly important for strategies to reduce bycatch. Transmission loss (TL) during acoustic propagation is an important determinant of those detection ranges, and it also influences animal detection functions used in passive acoustic monitoring. However, common assumptions regarding TL have rarely been tested. Here, TL of synthetic porpoise clicks was measured in porpoise habitats in Canada and Denmark, and field data were compared with spherical spreading law and ray-trace (Bellhop) model predictions. Both models matched... |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/publication-7395.pdf |
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| De Ruiter, Stacy; Bahr, Alexander; Blanchet, Marie-anne; Hansen, Sabina Fobian; Kristensen, Jakob Hojer; Madsen, Peter T.; Tyack, Peter L.; Wahlberg, Magnus. |
| Porpoise echolocation has been studied previously, mainly in target detection experiments using stationed animals and steel sphere targets, but little is known about the acoustic behaviour of free-swimming porpoises echolocating for prey. Here, we used small onboard sound and orientation recording tags to study the echolocation behaviour of free-swimming trained porpoises as they caught dead, freely drifting fish. We analysed porpoise echolocation behaviour leading up to and following prey capture events, including variability in echolocation in response to vision restriction, prey species, and individual porpoise tested. The porpoises produced echolocation clicks as they searched for the fish, followed by fast-repetition-rate clicks (echolocation buzzes)... |
| Tipo: Text |
Palavras-chave: Echolocation; Porpoise; Foraging; Buzz; Biosonar; Phocoena. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11111/8969.pdf |
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