Divergence in acoustic signals used by different populations of marine mammals can be caused by a variety of environmental, hereditary, or social factors, and can indicate isolation between those populations. Two types of genetically and morphologically distinct short-finned pilot whales, called the Naisa- and Shiho-types when first described off Japan, have been identified in the Pacific Ocean. Acoustic differentiation between these types would support their designation as sub-species or species, and improve the understanding of their distribution in areas where genetic samples are difficult to obtain. Calls from two regions representing the two types were analyzed using 24 recordings from Hawai‘i (Naisa-type) and 12 recordings from the eastern Pacific Ocean (Shiho-type). Calls from the two types were significantly differentiated in median start frequency, frequency range, and duration, and were significantly differentiated in the cumulative distribution of start frequency, frequency range, and duration. Gaussian mixture models were used to classify calls from the two different regions with 74% accuracy, which was significantly greater than chance. The results of these analyses indicate that the two types are acoustically distinct, which supports the hypothesis that the two types may be separate sub-species.

1.
Baird
,
R. W.
(
2016
).
The Lives of Hawai‘i’s Dolphins and Whales: Natural History and Conservation
(
University of Hawai‘i Press
,
Honolulu
), PP.
1
341
.
2.
Baird
,
R. W.
,
Webster
,
D. L.
,
Aschettino
,
J. M.
,
Schorr
,
G. S.
, and
McSweeney
,
D. J.
(
2013
). “
Odontocete cetaceans around the main Hawaiian Islands: Habitat use and relative abundance from small-boat sighting surveys
,”
Aquat. Mamm.
39
,
253
269
.
3.
Baker
,
M. C.
, and
Cunningham
,
M. A.
(
1985
). “
The biology of bird-song dialects
,”
Behav. Brain Sci.
8
,
85
100
.
4.
Balcazar
,
N. E.
,
Tripovich
,
J. S.
,
Klinck
,
H.
,
Nieukirk
,
S. L.
,
Mellinger
,
D. K.
,
Dziak
,
R. P.
, and
Rogers
,
T. L.
(
2015
). “
Calls reveal population structure of blue whales across the southeast Indian Ocean and southwest Pacific Ocean
,”
J. Mammal.
96
,
1184
1193
.
5.
Bonafonte
,
A.
,
Nogueiras
,
A.
, and
Rodriguez-Garrido
,
A.
(
1996
). “
Explicit segmentation of speech using Gaussian models
,” in
4th International Conference on Spoken Language Processing
, Vol. 4, pp.
1269
1272
.
6.
Bradbury
,
J.
, and
Vehrencamp
,
S.
(
1998
).
Principles of Animal Communication
(
Sinauer Associated, Inc.
,
Sunderland, MA
), pp.
1
882
.
7.
Cantor
,
M.
,
Shoemaker
,
L. G.
,
Cabral
,
R. B.
,
Flores
,
C. O.
,
Varga
,
M.
, and
Whitehead
,
H.
(
2015
). “
Multilevel animal societies can emerge from cultural transmission
,”
Nature Commun.
6
,
8091
.
8.
Conner
,
D. A.
(
1982
). “
Dialects versus geographic variation in mammalian vocalizations
,”
Anim. Behav.
30
,
297
298
.
9.
Crance
,
J. L.
,
Bowles
,
A. E.
, and
Garver
,
A.
(
2014
). “
Evidence for vocal learning in juvenile male killer whales, Orcinus orca, from an adventitious cross-socializing experiment
,”
J. Exp. Biol.
217
,
1229
1237
.
10.
Deecke
,
V. B.
,
Barrett-Lennard
,
L. G.
,
Spong
,
P.
, and
Ford
,
J. K. B.
(
2010
). “
The structure of stereotyped calls reflects kinship and social affiliation in resident killer whales (Orcinus orca)
,”
Naturwissenschaften
97
,
513
518
.
11.
Dehak
,
N.
,
Dumouchel
,
P.
, and
Kenny
,
P.
(
2007
). “
Modeling prosodic features with joint factor analysis for speaker verification
,”
IEEE Trans. Audio, Speech Lang. Process.
15
,
2095
2103
.
12.
Ding
,
W.
,
Wursig
,
B.
, and
Evans
,
W.
(
1995
). “
Whistles of bottlenose dolphins: Comparisons among populations
,”
Aquat. Mamm.
21
,
65
77
.
13.
Filatova
,
O. A.
,
Deecke
,
V. B.
,
Ford
,
J. K. B.
,
Matkin
,
C. O.
,
Barrett-Lennard
,
L. G.
,
Guzeev
,
M. A.
,
Burdin
,
A. M.
, and
Hoyt
,
E.
(
2012
). “
Call diversity in the North Pacific killer whale populations: Implications for dialect evolution and population history
,”
Anim. Behav.
83
,
595
603
.
14.
Filatova
,
O. A.
,
Guzeev
,
M. A.
,
Fedutin
,
I. D.
,
Burdin
,
A. M.
, and
Hoyt
,
E.
(
2013
). “
Dependence of killer whale (Orcinus orca) acoustic signals on the type of activity and social context
,”
Biol. Bull.
40
,
790
796
.
15.
Ford
,
J. K. B.
(
1989
). “
Acoustic behaviour of resident killer whales (Orcinus orca) off Vancouver Island, British Columbia
,”
Can. J. Zool.
67
,
727
745
.
16.
Ford
,
J. K. B.
(
1991
). “
Vocal traditions among resident killer whales (Orcinus orca) in coastal waters of British Columbia
,”
Can. J. Zool.
69
,
1454
1483
.
17.
Fraley
,
C.
, and
Raftery
,
A. E.
(
2002
). “
Model-based clustering, discriminant analysis, and density estimation
,”
J. Am. Stat. Assoc.
97
,
611
631
.
18.
Fraley
,
C.
,
Raftery
,
A. E.
,
Murphy
,
T. B.
, and
Scrucca
,
L.
(
2012
). “
mclust Version 4 for R: Normal mixture modeling for model-based clustering, classification, and density estimation
,”
Technical Report No. 597
, Department of Statistics, University of Washington, pp. 1–57.
19.
Freeberg
,
T. M.
,
Dunbar
,
R. I. M.
, and
Ord
,
T. J.
(
2012
). “
Social complexity as a proximate and ultimate factor in communicative complexity
,”
Philos. Trans. R. Soc. London
367
,
1785
1801
.
20.
Garland
,
E. C.
,
Goldizen
,
A. W.
,
Lilley
,
M. S.
,
Rekdahl
,
M. L.
,
Garrigue
,
C.
,
Constantine
,
R.
,
Hauser
,
N. D.
,
Poole
,
M. M.
,
Robbins
,
J.
, and
Noad
,
M. J.
(
2015
). “
Population structure of humpback whales in the western and central South Pacific Ocean as determined by vocal exchange among populations
,”
Conserv. Biol.
29
,
1198
1207
.
21.
Gero
,
S.
,
Whitehead
,
H.
, and
Rendell
,
L.
(
2016
). “
Individual, unit, and vocal clan level identity cues in sperm whale codas
,”
R. Soc. Open Sci.
3
,
150372
.
22.
Gillespie
,
D.
,
Caillat
,
M.
,
Gordon
,
J.
, and
White
,
P.
(
2013
). “
Automatic detection and classification of odontocete whistles
,”
J. Acoust. Soc. Am.
134
,
2427
2437
.
23.
Gillespie
,
D.
,
Mellinger
,
D. K.
,
Gordon
,
J.
,
McLaren
,
D.
,
Redmond
,
P.
,
McHugh
,
R.
,
Trinder
,
P.
,
Deng
,
X.-Y.
, and
Thode
,
A.
(
2009
). “
PAMGUARD: Semiautomated, open source software for real-time acoustic detection and localization of cetaceans
,”
J. Acoust. Soc. Am.
125
(
4
),
2547
.
24.
Graycar
,
P.
(
1976
).
Whistle Dialects of the Atlantic Bottlenose Dolphin
(
University of Florida
,
Gainesville
), pp.
1
180
.
25.
Hamilton
,
T. A.
,
Redfern
,
J. V.
,
Barlow
,
J.
,
Ballance
,
L. T.
,
Gerrodette
,
T.
,
Holt
,
R. S.
,
Forney
,
K. A.
, and
Taylor
,
B. L.
(
2009
). “
Atlas of cetacean sightings for Southwest Fisheries Science Center cetacean and ecosystem surveys: 1986-2005
,”
Technical Memorandum NOAA-TM-NMFS-SWFSC-440
, pp.
1
77
.
26.
Heimlich-Boran
,
J. R.
, and
Hall
,
C.
(
1993
). Social organization of the short-finned pilot whale, Globicephala macrorynchus, with special reference to the comparative social ecology of delphinids, Ph.D. thesis,
University of Cambridge
, pp.
1
134
.
27.
Hershey
,
J. R.
, and
Olsen
,
P. A.
(
2007
). “
Approximating the Kullback Leibler divergence between Gaussian mixture models
,” in
ICASSP, IEEE Int. Conf. Acoust. Speech Signal Process.
, Vol. 4, pp.
317
320
.
40.
Hill
,
M. C.
,
Oleson
,
E. M.
,
Ligon
,
A. D.
,
Martien
,
K. K.
,
Archer
,
F. I.
,
Baumann-Pickering
,
S.
,
Bendlin
,
A. R.
,
Dolar
,
L.
,
Merkens
,
K. P. B.
,
Milette-Winfree
,
A.
,
Morin
,
P. A.
,
Rice
,
A.
,
Robertson
,
K. M.
,
Trickey
,
J. S.
,
Ü
,
A. C.
,
Van Cise
,
A. M.
, and
Woodman
,
S. M.
(
2015
). “
Mitogenome phylogeography of short-finned pilot whales in the North Pacific, with reference to the Marianas Islands
,” in
Cetacean Monitoring in the Mariana Islands Range Complex
, PIFSC Data Report DR-15-003, U.S. Pacific Fleet Environmental Readiness Office, Appendix II, pp. 1–56, and Appendices therein.
28.
Holt
,
M. M.
,
Noren
,
D. P.
, and
Emmons
,
C. K.
(
2013
). “
An investigation of sound use and behavior in a killer whale (Orcinus orca) population to inform passive acoustic monitoring studies
,”
Mar. Mammal Sci.
29
,
E193
E202
.
29.
Janik
,
V.
, and
Slater
,
P.
(
2000
). “
The different roles of social learning in vocal communication
,”
Anim. Behav.
60
,
1
11
.
30.
Joyce
,
J.
(
2011
). “
Kullback-Leibler divergence
,”
Math. Comp. Simul.
30
,
720
722
.
31.
Kaplan
,
M.
,
Mooney
,
T.
,
Partan
,
J.
, and
Solow
,
A.
(
2015
). “
Coral reef species assemblages are associated with ambient soundscapes
,”
Mar. Ecol.: Prog. Ser.
533
,
93
107
.
32.
Kasuya
,
T.
(
1986
). “
Comparison of the life history parameters between two stocks of short-finned pilot whales of the Pacific coast of Japan
,” International Whaling Commission/SC38/SM10, pp.
1
32
.
33.
Kasuya
,
T.
, and
Marsh
,
H.
(
1984
). “
Life history and reproductive biology of the short-finned pilot whale, Globicephala macrorhynchus, off the Pacific coast of Japan
,”
Rep. Int. Whal. Comm. Spec. Issue
6
,
259
309
.
34.
Kasuya
,
T.
,
Miyashita
,
T.
, and
Kasamatsu
,
F.
(
1988
). “
Segregation of two forms of short-finned pilot whales off the Pacific coast of Japan
,”
Sci. Reports Whales Res. Inst.
39
,
77
90
.
35.
Kershenbaum
,
A.
,
Blumstein
,
D. T.
,
Roch
,
M. A.
,
Akçay
,
Ç.
,
Backus
,
G.
,
Bee
,
M. A.
,
Bohn
,
K.
,
Cao
,
Y.
,
Carter
,
G.
,
Cäsar
,
C.
,
Coen
,
M.
,
DeRuiter
,
S. L.
,
Doyle
,
L.
,
Edelman
,
S.
,
Ferrer-i-Cancho
,
R.
,
Freeberg
,
T. M.
,
Garland
,
E. C.
,
Gustison
,
M.
,
Harley
,
H. E.
,
Huetz
,
C.
,
Hughes
,
M.
,
Hyland Bruno
,
J.
,
Ilany
,
A.
,
Jin
,
D. Z.
,
Johnson
,
M.
,
Ju
,
C.
,
Karnowski
,
J.
,
Lohr
,
B.
,
Manser
,
M. B.
,
McCowan
,
B.
,
Mercado
,
E.
,
Narins
,
P. M.
,
Piel
,
A.
,
Rice
,
M.
,
Salmi
,
R.
,
Sasahara
,
K.
,
Sayigh
,
L.
,
Shiu
,
Y.
,
Taylor
,
C.
,
Vallejo
,
E. E.
,
Waller
,
S.
, and
Zamora-Gutierrez
,
V.
(
2014
). “
Acoustic sequences in non-human animals: A tutorial review and prospectus
,”
Biol. Rev.
91
,
13
52
.
36.
Kindt
,
R.
, and
Coe
,
R.
(
2005
).
Tree Diversity Analysis. A Manual and Software for Common Statistical Methods for Ecological and Biodiversity Studies
(
World Agroforestry Centre (ICRAF)
,
Nairobi
), pp.
1
18
.
38.
Mahaffy
,
S. D.
,
Baird
,
R. W.
,
McSweeney
,
D. J.
,
Webster
,
D. L.
, and
Schorr
,
G. S.
(
2015
). “
High site fidelity, strong associations, and long-term bonds: Short-finned pilot whales off the island of Hawai‘i
,”
Mar. Mammal Sci.
31
,
1427
1451
.
39.
McDonald
,
M. A.
,
Mesnick
,
S. L.
, and
Hildebrand
,
J. A.
(
2006
). “
Biogeographic characterisation of blue whale song worldwide: Using song to identify populations
,”
J. Cetacean Res. Manag.
8
,
55
65
.
41.
Mundinger
,
P. C.
(
1980
). “
Animal cultures and a general theory of cultural evolution
,”
Ethol. Sociobiol.
1
,
183
223
.
42.
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
.
43.
Musser
,
W. B.
,
Bowles
,
A. E.
,
Grebner
,
D. M.
, and
Crance
,
J. L.
(
2014
). “
Differences in acoustic features of vocalizations produced by killer whales cross-socialized with bottlenose dolphins
,”
J. Acoust. Soc. Am.
136
,
1990
2002
.
44.
Oksanen
,
J.
,
Blanchet
,
F. G.
,
Friendly
,
M.
,
Kindt
,
R.
,
Legendre
,
P.
,
McGlinn
,
D.
,
Minchin
,
P. R.
,
O'Hara
,
R. B.
,
Simpson
,
G. L.
,
Solymos
,
P.
,
Stevens
,
M. H. H.
,
Szoecs
,
E.
, and
Wagner
,
H.
(
2016
). “
vegan: Community ecology package
,” R package version 2.3-3, available at https://CRAN.R-project.org/package=vegan (Last viewed March 2016).
45.
Oremus
,
M.
,
Gales
,
R.
,
Dalebout
,
M. L.
,
Funahashi
,
N.
,
Endo
,
T.
,
Kage
,
T.
,
Steel
,
D.
, and
Baker
,
C. S.
(
2009
). “
Worldwide mitochondrial DNA diversity and phylogeography of pilot whales (Globicephala spp.)
,”
Biol. J. Linn. Soc.
98
,
729
744
.
46.
Oswald
,
J.
, and
Oswald
,
M.
(
2013
). ROCCA (Real-time Odontocete Call Classification Algorithm) User's Manual (Naval Facilities Engineering Command Atlantic, Norfolk, VA) HDR Environmental, Operations and Construction, Inc. Contract No. CON005-4394-009, Subproject 1647, pp.
1
42
.
47.
Papale
,
E.
,
Azzolin
,
M.
,
Gannier
,
A.
,
Lammers
,
M. O.
,
Martin
,
V. M.
,
Oswald
,
J.
,
Perez-gil
,
M.
, and
Giacoma
,
C.
(
2013
). “
Geographic variability in the acoustic parameters of striped dolphin's (Stenella coeruleoalba) whistles
,”
J. Acoust. Soc. Am.
133
,
1126
1134
.
48.
Rankin
,
S.
,
Barlow
,
J.
,
Barkley
,
Y.
, and
Valtierra
,
R.
(
2013
). “
A guide to constructing hydrophone arrays for passive acoustic data collection during NMFS shipboard cetacean surveys
,” Technical Memorandum NOAA-TM-NMFS-SWFSC-511, pp.
1
33
.
49.
Rendell
,
L. E.
,
Matthews
,
J. N.
,
Gill
,
A.
,
Gordon
,
J. C. D.
, and
Macdonald
,
D. W.
(
1999
). “
Quantitative analysis of tonal calls from five odontocete species, examining interspecific and intraspecific variation
,”
J. Zool. Soc. London
249
,
403
410
.
50.
Rendell
,
L.
,
Mesnick
,
S. L.
,
Dalebout
,
M. L.
,
Burtenshaw
,
J.
, and
Whitehead
,
H.
(
2012
). “
Can genetic differences explain vocal dialect variation in sperm whales, Physeter macrocephalus?
,”
Behav. Genet.
42
,
332
343
.
51.
Rendell
,
L. E.
, and
Whitehead
,
H.
(
2003
). “
Vocal clans in sperm whales (Physeter macrocephalus)
,”
Proc. Biol. Sci.
270
,
225
231
.
52.
Riesch
,
R.
,
Ford
,
J. K. B.
, and
Thomsen
,
F.
(
2006
). “
Stability and group specificity of stereotyped whistles in resident killer whales, Orcinus orca, off British Columbia
,”
Anim. Behav.
71
,
79
91
.
53.
Sayigh
,
L.
,
Quick
,
N.
,
Hastie
,
G.
, and
Tyack
,
P.
(
2013
). “
Repeated call types in short-finned pilot whales, Globicephala macrorhynchus
,”
Mar. Mammal Sci.
29
,
312
324
.
54.
Shapiro
,
A. D.
,
Tyack
,
P. L.
, and
Seneff
,
S.
(
2011
). “
Comparing call-based versus subunit-based methods for categorizing Norwegian killer whale, Orcinus orca, vocalizations
,”
Anim. Behav.
81
,
377
386
.
55.
Slabbekoorn
,
H.
, and
Smith
,
T. B.
(
2002
). “
Bird song, ecology and speciation
,”
Philos. Trans. R. Soc. Lond. B. Biol. Sci.
357
,
493
503
.
56.
Tubaro
,
P. L.
,
Segura
,
E. T.
, and
Handford
,
P.
(
1993
). “
Geographic variation in the song of the rufous-collared sparrow in Eastern Argentina
,”
Condor
95
,
588
595
.
57.
Van Cise
,
A. M.
,
Morin
,
P. A.
,
Baird
,
R. W.
,
Lang
,
A. R.
,
Robertson
,
K. M.
,
Chivers
,
S. J.
,
Brownell
,
R. L.
, and
Martien
,
K. K.
(
2016
). “
Redrawing the map: mtDNA provides new insight into the distribution and diversity of short-finned pilot whales in the Pacific Ocean
,”
Mar. Mammal Sci.
32
,
1177
1199
.
58.
Wada
,
S.
(
1988
). “
Genetic differentiation between two forms of short-finned pilot whales off the Pacific coast of Japan
,”
Sci. Reports Whales Res. Inst.
39
,
91
101
.
59.
Winn
,
H.
,
Thompson
,
T.
,
Cummings
,
W.
,
Hain
,
J.
,
Hudnall
,
J.
,
Hays
,
H.
, and
Steiner
,
W.
(
1981
). “
Song of the humpback whale—Population comparisons
,”
Behav. Ecol. Sociobiol.
8
,
41
46
.
60.
Yamase
,
H.
(
1760
).
Geishi [Natural History of Whales]
(
Osakashorin
,
Osaka
), pp.
1
70
.
61.
Yoshino
,
H.
,
Armstrong
,
K. N.
,
Izawa
,
M.
,
Yokoyama
,
J.
, and
Kawata
,
M.
(
2008
). “
Genetic and acoustic population structuring in the Okinawa least horseshoe bat: Are intercolony acoustic differences maintained by vertical maternal transmission?
,”
Mol. Ecol.
17
,
4978
4991
.
62.
Yurk
,
H.
,
Barrett-Lennard
,
L. G.
,
Ford
,
J. K. B.
, and
Matkin
,
C. O.
(
2002
). “
Cultural transmission within maternal lineages: Vocal clans in resident killer whales in southern Alaska
,”
Anim. Behav.
63
,
1103
1119
.

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