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Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar.
Ladegaard, Michael; Jensen, Frants Havmand; de Freitas, Mafalda; Ferreira da Silva, Vera Maria; Madsen, Peter Teglberg.
Afiliação
  • Ladegaard M; Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark michael.ladegaard@bios.au.dk.
  • Jensen FH; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
  • de Freitas M; Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark.
  • Ferreira da Silva VM; Laboratório de Mamíferos Aquáticos, Instituto Nacional de Pesquisas da Amazônia, Manaus, AM 69000-000, Brazil.
  • Madsen PT; Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia.
J Exp Biol ; 218(Pt 19): 3091-101, 2015 Oct.
Article em En | MEDLINE | ID: mdl-26447198
Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3 ± 6.1 dB re. 1 µPa, mean SLEFD of 132.1 ± 6.0 dB re. 1 µPa(2)s, mean Fc of 101.2 ± 10.5 kHz, mean BWRMS of 29.3 ± 4.3 kHz and mean ICI of 35.1 ± 17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6-10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9-25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Golfinhos / Ecolocação Limite: Animals País/Região como assunto: America do sul / Brasil Idioma: En Revista: J Exp Biol Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Dinamarca País de publicação: Reino Unido
Texto completo
Adicionar na Minha BVS
Imprimir
XML
PubMed Links
Buscar no Google

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Golfinhos / Ecolocação Limite: Animals País/Região como assunto: America do sul / Brasil Idioma: En Revista: J Exp Biol Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Dinamarca País de publicação: Reino Unido