Dear All, This recent paper sheds light on how harbour porpoises communicate acoustically using specific patterns of clicks with source properties comparable to normal echolocation clicks. Requests for reprints can be directed to tubbert@sol.dk <mailto:tubbert@sol.dk> All the best, Karin Tubbert Clausen CLICK COMMUNICATION IN HARBOUR PORPOISES PHOCOENA PHOCOENA Karin Tubbert Clausen1*, Magnus Wahlberg2, 3, Kristian Beedholm1, Stacy DeRuiter4,5 and Peter Teglberg Madsen1,5 1 Zoophysiology, Department of Biological Sciences, Aarhus University, Build. 1131, C.F. Moellers Alle, 8000 Aarhus C, Denmark 2 Fjord & Baelt, Margrethes Plads 1, 5300 Kerteminde, Denmark 3 University of Southern Denmark, Hindsholmsvej 11, 5300 Kerteminde, Denmark 4 IFREMER, Service Acoustique et Sismique, BP 70, 29280 Plouzan��, France 5 Woods Hole Oceanographic Institution, Woods Hole, 02543 MA, USA ABSTRACT Sound plays an important role for toothed whales in foraging and communication. However, little is known about acoustic communication in the toothed whale species that only produce narrow band high frequency (NBHF) clicks, such as the harbour porpoise Phocoena phocoena. To study acoustic behaviour and to quantify the source parameters of porpoise communication signals, the acoustic and swimming behaviour of three adults and one calf were recorded using an array of hydrophones, acoustic tags and an overhead video camera. We tested the hypothesis that different behavioural interactions between porpoises involve specific click patterns for communication and measured the source characteristics of these click patterns to estimate the active space of porpoise click communication. Our results provide strong evidence that porpoises communicate acoustically using specific patterns of clicks with source properties comparable to normal echolocation clicks, and that they employ stereotyped aggressive click patterns, exposing conspecifics to received levels of up to 180 dB re 1 ��Pa (pp). The measured source properties render estimated active spaces of less than 1000 meters for porpoises�� communication sounds. Compared to other cetaceans, porpoises must therefore remain much closer to be able to communicate acoustically. Keywords: harbour porpoise, Phocoena phocoena, click communication, mother-calf pair, active space Karin Tubbert Clausen Zoophysiology, Department of Biological Sciences Aarhus University, Build. 1131, CF Mollers Alle 8000 Aarhus C, Denmark Web: www.marinebioacoustics.com <http://www.marinebioacoustics.com> sender_logo <P><p><font face="Arial, Helvetica, sans-serif" size="2" style="font-size:13.5px">_______________________________________________________________<BR>http://debat.sol.dk/ - din mening t�ller!</font>