Bottlenose dolphins (Tursiops truncatus) wore opaque suction cups over their eyes while stationing behind an acoustically opaque door. This put the dolphins in a known position and orientation. When the door opened, the dolphin clicked to detect targets. Trainers specified that Dolphin S emit a whistle if the target was a 7.5 cm water filled sphere, or a pulse burst if the target was a rock. S remained quiet if there was no target. Dolphin B whistled for the sphere. She remained quiet for rock and for no target. Thus, S had to choose between three different responses, whistle, pulse burst, or remain quiet. B had to choose between two different responses, whistle or remain quiet. S gave correct vocal responses averaging 114 ms after her last echolocation click (range 182 ms before and 219 ms after the last click). Average response for B was 21 ms before her last echolocation click (range 250 ms before and 95 ms after the last click in the train). More often than not, B began her whistle response before her echolocation train ended. The findings suggest separate neural pathways for generation of response vocalizations as opposed to echolocation clicks.

1.
Amundin
,
M.
, and
Andersen
,
S. H.
(
1983
). “
Bony nares air pressure and nasal plug muscle activity during click production in the harbour porpoise, Phocoena phocoena, and the bottlenosed dolphin, Tursiops truncatus
,”
J. Exp. Biol.
105
,
275
282
.
2.
Au
,
W. W. L.
,
Floyd
,
R. W.
,
Penner
,
R. H.
, and
Murchison
,
A. E.
(
1974
). “
Measurement of echolocation signals of the Atlantic bottlenose dolphin, Tursiops truncatus (Montagu), in open waters
,”
J. Acoust. Soc. Am.
56
,
1280
1290
.
3.
Bullock
,
T. H.
, and
Ridgway
,
S. H.
(
1972
). “
Evoked potentials in the central auditory system of alert porpoises to their own and artificial sounds
,”
J. Neurobiology
3
,
79
99
.
4.
Bullock
,
T. H.
, and
Gurevich
,
V.
(
1979
). “
Soviet literature on the nervous system and psychobiology of Cetacea
,”
Int. Rev. Neurobiol.
21
,
48
127
.
5.
Chaplin
,
M.
,
Kamolnick
,
T.
,
Cranford
,
T. W.
,
Van Bonn
,
W.
,
Carder
,
D. A.
, and
Ridgway
,
S.H.
(
2000
). “
Conditioning Tursiops truncatus for nasal passage endoscopy
,”
Marine Mammals: Public Disp. Res.
4
,
7
13
.
6.
Cranford
,
T. W.
,
Elsberry
,
W. R.
,
Van Bonn
,
W. G.
,
Carr
,
J. A.
,
Chaplin
,
M. S.
,
Blackwood
,
D. S.
,
Carder
,
D. A.
,
Kamolnick
,
T.
,
Todd
,
M.
, and
Ridgway
,
S. H.
(
2011
). “
Observation and analysis of sonar signal generation in the bottlenose dolphin (Tursiops truncatus): Evidence for two sonar sources
,”
J. Exp. Marine Biol. Ecol.
407
,
81
96
.
7.
Elsberry
,
W. R.
(
2003
). “
Interrelationships between intranarial pressure and biosonar clicks in bottlenose dolphins (Tursiops truncatus)
,” Ph.D. thesis,
Texas A&M University
, College Station, Texas.
8.
Fenzl
,
T.
, and
Schuller
,
G.
(
2005
). “
Echolocation calls and communication calls are controlled differentially in the brainstem of the bat Phyllostomus discolor
,”
BMC Biol.
3
,
17
29
9.
Kadane
,
J.
, and
R. H.
Penner
. (
1983
). “
Range ambiguity and pulse interval jitter in the bottlenose dolphin
,”
J. Acoust. Soc. Am.
74
,
1059
1062
.
10.
Lilly
,
J. C.
, and
Miller
,
A. M.
(
1961
). “
Sounds emitted by the bottlenose dolphin
,”
Science
133
,
1689
1693
.
11.
Moore
,
P. W.
, and
Pawloski
,
D. A.
(
1990
). “
Investigations on the control of echolocation pulses in the dolphin (Tursiops truncatus)
,” in
Sensory Abilities of Cetaceans
, edited by
J.
Thomas
and
R.
Kastelein
(
Plenum
,
New York
), pp.
305
316
.
12.
Morozov
,
V. P.
,
Akopian
,
A. I.
,
Burdin
,
V. I.
,
Zaytseva
,
K. A.
, and
Sokovykh
,
Yu. A.
(
1972
). “
Repetition rate of ranging signals of dolphins as a function of distance to target
,”
Biofizika
17
,
139
144
.
13.
Muller
,
Mark
,
John
,
W.
,
Allen
,
S.
,
Whitlow
,
W.
,
Au
,
L.
,
Nachtigall
,
Paul E.
(
2008
). “
Time-frequency analysis and modeling of the backscatter of categorized dolphin echolocation clicks for target discrimination
,”
J. Acoust. Soc. Am.
124
,
657
666
.
14.
Murchison
,
A. E.
(
1980
). “
Detection range and range resolution of echolocating bottlenose porpoise (Tursiops truncatus)
,” in
Animal Sonar Systems
, edited by
R. G.
Busnel
and
J. F.
Fish
(
Plenum Press
,
New York
), pp.
43
70
.
15.
Murray
,
S. O.
,
Mercado
,
E.
, and
Roitblat
,
H. L.
(
1998
). “
Characterizing the graded structure of false killer whale (Pseudorca crassidens) vocalizations
,”
J. Acoust. Soc. Am.
104
,
1679
1688
.
16.
Penner
,
R. H.
(
1988
). “
Attention and detection in dolphin echolocation
,” in
Animal Sonar: Processes and Performance
, edited by
P. E.
Nachtigall
and
P. W. B.
Moore
(
Plenum Press
,
New York
), pp.
707
713
.
17.
Ridgway
,
S. H.
and
Carder
,
D. A.
(
1988
). “
Nasal pressure and sound production in an echolocating white whale, Delphinapterus leucas
,” in
Animal Sonar: Processes and Performance
, edited by
P. E.
Nachtigall
and
P. W. B.
Moore
(
Plenum Press
,
New York
), pp.
53
60
.
18.
Ridgway
,
S. H.
, and
Carder
,
D. A.
(
1997
). “
Hearing deficits measured in some Tursiops truncatus, and discovery of a deaf/mute dolphin
,”
J. Acoust. Soc. Am.
101
,
590
594
.
19.
Ridgway
,
S. H.
(
1990
) “
The central nervous system of the bottlenose dolphin
,” in
The Bottlenose Dolphin, Tursiops spp
, edited by
S.
Leatherwood
and
R.
Reeves
(
Academic Press
,
New York
), pp.
69
97
.
20.
Ridgway
,
S. H.
,
Carder
,
D. A.
,
Kamolnick
,
T.
,
Smith
,
R. R.
,
Schlundt
,
C. E.
, and
Elsberry
,
W. R.
(
2001
). “
Hearing and whistling in the deep sea: Depth influences whistle spectra but does not attenuate hearing by white whales (Delphinapterus leucas, Odontoceti, Cetacea)
,
J. Exp. Biol.
204
,
3829
3841
.
21.
Ridgway
,
S. H.
,
Keogh
,
M.
,
Carder
,
D. A.
,
Finneran
,
J. J.
,
Kamolnick
,
T.
,
Todd
,
M.
, and
Goldblatt
,
A.
(
2009
). “
Dolphins maintain cognitive performance during 72 to 120 hours of continuous auditory vigilance
,”
J. Exp. Biol.
212
,
1519
1527
.
22.
Ridgway
,
S. H.
, (
2011
). “
Neural time and movement time in choice of whistle or pulse burst responses to different auditory stimuli by dolphins
,”
J. Acoust. Soc. Am.
129
,
1073
1080
.
23.
Schlundt
,
C. E.
,
Finneran
,
J. J.
,
Carder
,
D. A.
, and
Ridgway
,
S. H.
(
2000
). “
Temporary shift in masked hearing thresholds (MTTS) of bottlenose dolphins, Tursiops truncatus, and white whales, Delphinapterus leucas, after exposure to intense tones
,”
J. Acoust. Soc. Am.
107
(
4
),
3496
3508
.
24.
Supin
,
A. Ya.
,
Mukhametov
,
L. M.
,
Ladygina
,
T. F.
,
Popov
,
V. V.
,
Mass
,
A. M.
, and
Polyakova
,
I. G.
(
1978
). “
An electrophysiological investigation of the dolphin’s brain
,”
Izd. Nauka. Moscow
, p.
300
.
You do not currently have access to this content.