Source levels of echolocating free-ranging Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) were calculated using a range estimated by measuring the time delays of the signals via the surface and bottom reflection paths to the hydrophone, relative to the direct signal. Peak-to-peak source levels for finless porpoise were from 163.7 to . The source levels are highly range dependent and varied approximately as a function of the one-way transmission loss for signals traveling from the animals to the hydrophone.
REFERENCES
1.
Akamatsu
, T.
, Wang
, D.
, Nakamura
, K.
, and Wang
, K.
(1998
). “Echolocation range of captive and free-ranging baiji (Lipotes vexillifer), finless porpoise (Neophocaena phocaenoides), and bottlenose dolphin (Tursiops truncatus)
,” J. Acoust. Soc. Am.
104
, 2511
–2516
.2.
Akamatsu
, T.
, Wang
, D.
, Wang
, K.
, and Naito
, Y.
(2005a
). “Biosonar behaviour of free-ranging porpoises
,” Proc. R. Soc. London
272
, 797
–801
.3.
Akamatsu
, T.
, Wang
, D.
, and Wang
, K.
(2005b
). “Off-axis sonar beam pattern of free-ranging finless porpoises measured by a stereo pulse event data logger
,” J. Acoust. Soc. Am.
117
, 3325
–3330
.4.
Akamatsu
, T.
, Wang
, D.
, Wang
, K.
, and Wei
, Z.
(2001
). “Comparison between visual and passive acoustic detection of finless porpoises in the Yangtze River, China
,” J. Acoust. Soc. Am.
109
, 1723
–1727
.5.
Au
, W. W. L.
(1993
). The Sonar of Dolphins
(Springer-Verlag
, New York).6.
Au
, W. W. L.
and Benoit-Bird
, K. J.
(2003
). “Automatic gain control in the echolocation system of dolphins
,” Nature
423
, 861
–863
.7.
Au
, W. W. L.
, Ford
, J. K. B.
, Horne
, J. K.
, and Newman Allman
, K. A.
(2004
). “Echolocation signals of free-ranging killer whales (Orcinus orca) and modeling of foraging for Chinook salmon (Oncorhynchus tshawytscha)
,” J. Acoust. Soc. Am.
115
, 901
–909
.8.
Au
, W. W. L.
and Würsig
, B.
(2004
). “Echolocation signals of dusky dolphins (Lagenorhynchus obscurus) in Kaikoura, New Zealand
,” J. Acoust. Soc. Am.
115
, 2307
–2313
.9.
Aubauer
, R.
, Lammers
, M. O.
, and Au
, W. W. L.
(2000
). “One-hydrophone method of estimating distance and depth of phonating dolphins in shallow water
,” J. Acoust. Soc. Am.
107
, 2744
–2749
.10.
Goold
, J. C.
and Jefferson
, T. A.
(2002
). “Acoustic signals from free-ranging finless porpoises (Neophocaena phocaenoides) in the waters around Hong Kong
,” Raffles Bull. Zool., Suppl.
10
, 131
–139
.11.
Hartley
, D. J.
(1992
). “Stabilization of perceived echo amplitudes in echolocating bats. II. The acoustic behavior of the big brown bat, Eptesicus fuscus, when tracking moving prey
,” J. Acoust. Soc. Am.
91
, 1133
–1149
.12.
Kamminga
, C.
, Kataoka
, T.
, and Engelsma
, F. J.
(1986
). “Investigations on cetacean sonar VII: Underwater sounds of Neophocaena phocaenoides of the Japanese coastal population
,” Aquat. Mamm.
12
, 52
–60
.13.
Ketten
, D. R.
(2000
). in Hearing by Whales and Dolphins
, edited by W. W. L.
Au
, A. N.
Popper
, and R. R.
Fay
(Springer-Verlag
, New York), pp. 43
–108
.14.
Lammers
, M. O.
, Au
, W. W. L.
, Aubauer
, R.
, and Nachtigall
, P. E.
(2003
). “A comparative analysis of the pulsed emissions of free-ranging Hawaiian spinner dolphins (Stenella longirostris)
,” in Echolocation in bats and dolphins
, edited by J. A.
Thomas
, C. F.
Moss
, and M.
Vater
(University of Chicago
, Chicago), pp. 414
–419
.15.
Li
, S.
, Wang
, K.
, Wang
, D.
, and Akamatsu
, T.
(2005a
). “Echolocation signals of the free-ranging Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientialis)
,” J. Acoust. Soc. Am.
117
, 3288
–3296
.16.
Li
, S.
, Wang
, K.
, Wang
, D.
, and Akamatsu
, T.
(2005b
). “Origin of the double- and multi-pulse structure of echolocation signals in Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientialis)
,” J. Acoust. Soc. Am.
118
, 3934
–3940
.17.
Rasmussen
, M. H.
, Miller
, L. A.
, and Au
, W. W.L.
(2002
). “Source levels of clicks from free-ranging white-beaked dolphins (Lagenorhynchus albirostris Gray 1846) recorded in Icelandic waters
,” J. Acoust. Soc. Am.
111
, 1122
–1125
.18.
Simmons
, J. A.
, Moffat
, A. J. M.
, and Masters
, W. M.
(1992
). “Sonar gain control and echo detection thresholds in the echolocating bat, Eptesicus fuscus
,” J. Acoust. Soc. Am.
91
, 1150
–1163
.19.
Thode
, A.
, Mellinger
, D. K.
, Stienessen
, S.
, Martinez
, A.
, and Mullin
, K.
(2002
). “Depth-dependent acoustic features of diving sperm whales (Physeter macrocephalus) in the Gulf of Mexico
,” J. Acoust. Soc. Am.
112
, 308
–321
.20.
Wang
, K.
, Wang
, D.
, Akamatsu
, T.
, Li
, S.
, and Xiao
, J.
(2005
). “A passive acoustic monitoring method applied to observation and group size estimation of finless porpoises
,” J. Acoust. Soc. Am.
118
, 1180
–1185
.© 2006 Acoustical Society of America.
2006
Acoustical Society of America
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