COMPARISON OF SONGS OF HUMPBACK WHALES(MEGAPTERA NOVAEANGLIAE) RECORDED IN
JAPAN, HAWAII, AND MEXICO DURING THE WINTER OF 1989

DAVID A. HELWEG, 1) LOUIS M. HERMAN, 2) SATORU YAMAMOT02l
AND PAUL H. FORESTELL3)
ABSTRACT

Recordings of humpback whale (Megaptera novaeangliae) song were obtained
between 10 March and 14 April 1989 from the Bonin Islands and the
Ryukyuan Islands of Japan, the Hawaiian Islands, and the southeastern Baja
Peninsula of Mexico. Through analyses of the song samples obtained, seven"themes" were identified in Hawaiian and in Bonin song and six in Mexicansong. Theme similarities across these three regions arranged themselves
hierarchically: Hawaii and Mexico shared five themes in common, and did
not share three ; Hawaii and Bonin shared four themes and did not share
three; and Mexico and Bonin shared three themes and did not share six.
Three themes appeared in all three regions. The song samples from Ryukyu
were all of short duration and were likely an incomplete record of the entire
song repertoire. Nevertheless, of the three themes identified in the
Ryukyuan samples, two appeared in Bonin song and none in Mexican and
Hawaiian song. Overall, the thematic data suggested that there is acoustic
contact during some portion of the migratory cycle among the whales wintering in Mexico, Hawaii, and the Bonin Islands.
Key words: humpback whale, acoustic communication, stock identity, song
dialects
INTRODUCTION

Humpback whales (Megaptera novaeangliae) migrate annually between highlatitude summer grounds where feeding occurs and low-latitude winter grounds.
The behavior of the whales on the winter grounds (e.g., Herman, Forestell andDepartment of Psychology, University of Hawaii, 2430 Campus Road, Honolulu, Hawaii, 96822 U.S.A.,
and Kewalo Basin Marine Mammal Laboratory.
2) Kewalo Basin Marine Mammal Laboratory, University of Hawaii, 1129 Ala Moana Blvd., Honolulu,
Hawaii, 96814 U.S.A.
3) Pacific Whale Foundation, 101 N. Kihei Road, Kihei, Maui, Hawaii, 96753 U.S.A.
I)

Sci. Rep. Cetacean Res.,
No. 1, 1990, 1-20

2

HELWEG, HERMAN, YAMAMOTO AND FORESTELL

Antinoja, 1980; Tyack, 1981; Darling, Gibson and Silber, 1983; Glockner andVenus, 1983; Baker and Herman, 1984) and their reproductive physiology
during the winter months (Chittleborough, 1955, 1958, 1965) suggest that reproductive activities are predominant during the winter season.
Humpback whales produce a complex vocalization first characterized as"song" by Payne and McVay (1971). Singing peaks during the winter months(Winn and Winn, 1978; Thompson and Friedl, 1982; Helweg, 1989), although it
has been reported occasionally late in the fall on the feeding grounds (Matilla,
Guinee and Mayo, 1987; Mcsweeney, Chu, Dolphin and Guinee, 1989) andalong migratory pathways (Tyack and Whitehead, 1983; Kaufman and Jenkins,
1985). The singing whales that have been sexed have proven to be male (Winn,
Bischoff and Taruski, 1973; Glockner, 1983). The correlation of song production and seasonal gonadal activity suggests that song plays a role in the mating
system, although that role is not yet established (cf. Tyack, 1981, 1983; Baker
and Herman, 1984; Mobley, Herman and Frankel, 1988).
Humpback song is dynamic; songs in a given geographical region change
during the course of each winter season, yet at any given time singers within theregion appear to converge on the same or nearly the same rendition (Winn andWinn, 1978; Guinee, Chu and Dorsey, 1983; Payne, Tyack and Payne, 1983;
Payne and Payne, 1985). The function of the seasonal changes in song and of
the convergence of most singers on the current rendition remain speculative (cf.
Winn and Winn, 1978; Frumhoff, 1983; Payne and Guinee, 1983; Payne et al.,
1983; Payne and Payne, 1985; Chu and Harcourt, 1986).
Previous studies have found substantial song differences between geographically isolated stocks of humpbacks in separate oceans: in particular, theNorth Atlantic, North Pacific, and South Pacific Oceans (Winn, Thompson,
Cummings, Hains, Hudnall, Hays and Steiner, 1981; Payne and Guinee, 1983;
Kaufman and Jenkins, 1985). Similarities in the songs of whales in different
wintering areas within an ocean have also been found (Winn and Winn, 1978;
Payne and Guinee, 1983). These authors have suggested that whales in different
wintering areas singing the same rendition of song must be in acoustic contact
during some portion of their annual cycle when song is produced. Contact may
occur in the summer feeding grounds, during migration, through visits to morethan one wintering ground during a season by some whales, and through visits
to different wintering grounds in different seasons by some whales.
Payne and Guinee (1983) found that humpback songs recorded at about
the same time near Maui in the Hawaiian lsalands and at Isla Socorro off thewest coast of Mexico were similar to each other, suggesting that the whales inthese two areas may constitute one stock. In this paper, we extend the North
Pacific analysis by comparing songs recorded at about the same time in Hawaii,
Mexico, and Japan.
Sci. Rep. Cetacean Res.,
No. 1, 1990

3

HUMPBACK WHALE SONGS

70•

50•

NORTH
PACIFIC40'

ISLASDEREVILLAG!GE:OO·:--~PHILIPPINE

10" .~

20•

10•

$£Ai

140°

120°

o•

Fig. 1. The North Pacific Ocean, showing documented summer feeding sites forhumpback whales from the western Gulf of Alaska through to southeast Alaska andthe Farallon Islands (see text). Additionally shown are the locations of the four
wintering areas from which songs were obtained in Mexico, the Hawaiian Islands, theBonin Islands, and the Ryukyuan Islands.

The stocks of humpbacks in the North Pacific Ocean
Fig. 1 shows areas of seasonal aggregations of humpback whales in the North
Pacific Ocean and neighboring waters. Five summer feeding sites have been
documented in the central and eastern North Pacific (Baker, Herman, Perry,
Lawton, Straley, Wolman, Kaufman, Winn, Hall, Reinke and Ostman, 1986):
the Farallon Islands, southeast Alaska, Yakutat Bay, Prince William Sound,and the western Gulf of Alaska. Photographic identifications have revealed that
individual whales tend to return to the same feeding site each year (Darling andJurasz, 1983; Darling and Mcsweeney, 1985; Baker et al., 1986), resulting in an
apparent segregation of feeding stocks. The historical feeding range of
humpback whales extended beyond the western Gulf of Alaska through the
Aleutian Islands and northward into the Bering and Chukchi Seas, as well as
into the Okhotsk Sea and along the Kamchatka Peninsula (Kellogg, 1929;
Nishiwaki, 1966; Tomilin, 1967; Nikulin, 1969; Nemoto, 1978; Rice, 1978). The
degree of current use of these areas is not known.
Three primary winter aggregations have been identified. One is located in
Mexican waters around the Baja Peninsula, Gulf of California, and Islas deRevillagigedo (Urban and Aguayo, 1987). A second, reportedly larger, aggregation forms around the waters of the main Hawaiian Islands (Herman andSci. Rep. Cetacean Res.,
No. 1, 1990

4

HELWEG, HERMAN, YAMAMOTO AND FORESTELL

Antinoja, 1977; Herman et al., 1980; Baker and Herman, 1981; Darling andJurasz, 1983). A third wintering ground was traditionally located south ofJapan, among the Bonin, Ryukyuan, and Marianas Islands (Townsend, 1935;
Dawbin, 1966; Nishiwaki, 1959, 1960, 1962, 1966; Tomilin, 1967; Nikulin,1969). The western population was greatly reduced by commercial whaling(Tomilin, 1967), and was unaccounted for as late as 1984 (Johnson and Wolman,
1984). Recent sightings indicate, however, that humpback whales are returning
to the Bonin and Ryukyuan winter grounds.
Exchange among the wintering grounds between seasons has been
documented for Hawaiian and Mexican whales, although it appears to be a relatively rare occurrence (Baker et al., 1986; Darling and Jurasz, 1983; Darling andMcsweeney, 1985). Travel between Mexico and Hawaii within a season has
been reported only once thus far, using photographic data from several
laboratories and the archival laser disc records of the National Marine Mammal
Laboratory. 1) There are, as yet, few photographic records of humpback whales
from Japanese waters, but it seems likely that the between- or within-season
exchange between Hawaii and Japan would be no more frequent than thatobserved between Hawaii and Mexico.

Humpback whale song
Payne and McVay (1971) contended that the long, complex, vocalizations of the
humpback whale in or near the winter grounds could be classified as "song"according to a definition of song as a series of sounds repeated in a recognizable
sequence or pattern in time (Broughton, 1963). Payne and McVay (1971) and
Payne et al. (1983) further described the hierarchical organization of humpback
whale song: at the lowest level were discrete notes, or units, defined as "theshortest sounds in the song which seem continuous to the human ear" (Payne
et al., 1983, p. 15); small repeated groups of units were organized into phrases,
often consisting of two subphrases, each containing repeated sounds; groups ofphrases made up a theme; and, finally, the song itself was "a series of different
themes given in a predictable order" (Payne et al., 1983, p. 17). A song typicallymay last for perhaps 8 to 12 minutes. Successive songs sung without pause constituted a song session.
Transitional phrases may occur at the junction between themes (Payne,
et al., 1983). These transitions are often composed of the first subphrase of thepreceding phrase and the second subphrase of the following phrase (Frumhoff,
1) Identification of a single humpback whale traversing from Mexico to Hawaii during the 1986 winter season
was made by the National Marine Mammal Laboratory, Seattle, using their computer photographic identification system and photographic records from Mexico in 1986 supplied by the Universidad Autonoma de Mexico,and records from Hawaii for that same year, supplied by the Pacific Whale Foundation. Additionally, the same
whale was photo-identified in previous years in Hawaii by the Kewalo Basin Mammal Laboratory, by theCenter for Whale Studies, and by the West Coast Whale Research Foundation.
Sci. Rep. Cetacean Res.,
No. 1, 1990

HUMPBACK WHALE SONGS

51983). Phrases within a theme may vary in the repetition rate of the subphrases
or of the units (Payne and McVay, 1971; Payne, 1978).
The singing whale is most often alone (Winn and Winn, 1978; Tyack,1981). The whale may remain submerged in a particular small area for long
periods, surfacing at intervals of perhaps 8 to 15 min and then diving again
after a short respiratory bout. Swimming while singing has been reported occasionally, as has singing in the company of other whales (Tyack, 1981; Baker andHerman, 1984; Frankel, Clark, Herman, Gabriele, Hoffhines, Freeman and
Patterson, 1989). During some years of our observations in Hawaii, surfacing
could be predicted by a series of "ratcheting" sounds, apparently similar to
those described by Winn and Winn (1978) as preceding surfacing of North
Atlantic humpback whales in the winter grounds near Puerto Rico. The ratchetsounds we have observed during 1987 to 1989 had a creaking, staccato character, and were usually followed by one or more short, higher frequency"whines". There is commonly a marked attenuation of sound prior to andduring surfacing.
Source levels for humpback song are relatively loud, on the order of 155
dB (re 1 µ,Pa at 1 m) (Levenson, 1972). Payne and Guinee (1983) argued, however, that humpback song can probably be heard by other whales only at
distances of less than 20 km, based on the model of sound propagation developed by Payne and Webb (1971). Winn and Winn (1978) reported hearing
humpback whale song on listening hydrophones at a distance as great as 32 km
and Frankel et al., (1989), using a three-element hydrophone array, have locatedsome singing whales at distances estimated as 20 km. These various theories anddata suggest that acoustic contact between humpback whales, for song vocalizations, is probably limited to relatively short ranges of, say, less than 40 km.
MATERIALS AND METHODS

Because humpback whale song may change to varying degrees over the courseof a winter season, we chose to compare songs obtained at roughly comparable
points in time from the different geographic regions. Table 1 lists the locations
and dates within the Mexican, Hawaiian and Japanese regions from which our
1989 song samples were obtained, and gives the duration of each sample. Fig. 2
provides detailed maps of the specific location from which song samples wereobtained within each region. Song samples were obtained in Mexico on March
10 and 11; in Hawaii on March 12 and 15, and on April 4; in the Ryukyuan
Islands on March 19, 22 and 23 March; and in the Bonin Islands on April 14.
Thus, with the exception of the Bonin songs and one Hawaii song, samples ofsong were available within the 3-week interval from March 10 to March 24.
Earlier (1979) comparisons of Mexican and Hawaiian song (Payne and Guinee,1983) were similarly based on recordings made in the month of March. The
Sci. Rep. Cetacean Res.,
No. 1, 1990

6

HELWEG, HERMAN, YAMAMOTO AND FORESTELL
23•

11o•oo'w

109•40'109•20'

1so w

156°

158°

0

IO'r-r~~-.--~~~~~~--.-~~~~~----,----,A';B

BAJA CALIFORNIA (MEXICO)SAN JOSE .·. :..:.
,/DEL CA(30 .: .. __,-,,_..p,_c_:::j/N.:./ y

23°"
oo'

!
,,,

N

L'~~~

, _____ )_,,--;__,,----=;'-'

22°
50'

22°

GORDA
BANKS
0.__,__,
10
km

27°

",'

,___,5

D

ID
N,-,-------,-----,----,-----,----,,----,~~~

c

km

ID

VOTO~OJIMA',,-

lWA L.JISLANDL~142°!0 w-0· G~

YAKABI,.,;,~~~\/

IWA'15t/l "·I(J . L~,'

-

l(jl

I>

~

~;J

CHICHIJIMA•/

SOUTH fi-;oroKo,-~ANl',

27°
DD' -

,

D

N

km

• .

KUBA·

.

="

o
o

tl

0

. TOKASIKI

•
"

JIMA

/
142°20'127°10'E

127°20'Fig. 2. Details of the study regions from which recordings were made. Each corresponds to an inset box on Fig. 1 but is not identical to the area delimited by the box in
Fig. 1. The specific recording sites are shown in boxes and correspond to the locations
given in Table 1. The dotted lines indicate the 200m isobath.

TABLE 1. DATES, LOCATIONS AND DURATIONS OF 1989 HUMPBACK WHALE SONGSAMPLES, AND THE RESEARCH GROUP PROVIDING EACH SAMPLE.
Date

Region (location)

Duration(min:sec)

Code

Group

lOMarch
10 March
11 March

Mexico (Gorda Bank)
Mexico (Gorda Bank)
Mexico (Gorda Bank)

5:13
20:20
27:05

MEX310A
MEX310B
MEX311CWR;UNACWR;UNACWR;UNA

12 March
15 March
4AprilHawaii (South Kohala)
Hawaii (South Kohala)
Hawaii (Maalaea)

30:00
26:24
31:20

HI312
HI315
HI404

KBMML
KBMML
PWF

19March22March23MarchRyukyu (Otoko Iwa)
Ryukyu (Kuba)
Ryukyu (Yakabi)

4:57
2:23
2:56

RYU319RYU322RYU323

TA;TN
TA;TN
TA;TN

14 April
14 April

Bonin (South Island)
Bonin (Takojima)

32:09
18:00

BON414A
BON414B

PWF
PWF

Group codes: CWR =Center for Whale Research; UNA= Universidad Nacional Autononoma de Mexico;
KBMML = Kewalo Basin Marine Mammal Laboratory; PWF =Pacific Whale Foundation; TA= Toba
Aquarium; TN = Tsuneo Nakamura (Volvox).
Sci. Rep. Cetacean Res.,No. I, 1990

HUMPBACK WHALE SONGS

7hydrophones and recording equipment used by the various research groups to
obtain the 1989 songs varied, but reportedly all systems had frequency responses
flat from 50 Hz to at least 10,000 Hz.
The samples from Hawaii and the Bonin Islands contain full songs without
interruption. Although the Mexican song samples were interrupted at several
points when the research group pursued fluke photography as the singers surfaced, two of the song sessions are long enough (ea. 20 to 27 min) to make itlikely that all sounds made by the whales are represented in the song samples(K. Balcomb, pers. comm.). The three samples from Ryukyu were all of shortduration, but one (RYU319) does contain a cycle of themes that returns beyondthe "starting" theme.
Sonograms of representative phrases from each theme, as well as of "atypical" transitional phrases, were made on a Kay (Series 7800) SonoGraph. Previously published sonograms of humpback song have typically limited the upper
frequency to 2.0 kHz (Payne and McVay, 1971), or 2.5 kHz, and have provided
tracings only of the fundamental frequency (e.g., Frumhoff, 1983; Mcsweeney
et al., 1989; Payne and Guinee, 1983; Payne et al., 1983). We chose instead an
upper frequency limit of 4 kHz (using an effective bandwidth of 150 Hz) because several subphrases had fundamental frequencies close to or above 2.5
kHz, and a great deal of sound energy lay in harmonics. The harmonic structureof the songs proved helpful in discriminating similarities and differences between
phrases.
The obtained sonograms were used to identify units, subphrases, phrases
and themes. There was some variation in the repetition rate of subphrases
within phrases, and phrases within themes, but this variation occurred bothwithin and between songs. The variation was ascribed to idiosyncrasies of particular whales rather than to a group characteristic and was not taken into
consideration in the analyses of similarties and differences across regions.
Using HI315 (Table 1) as the reference song, the first theme following thesurface ratchet was labelled A. This is the same criterion as used by Winn andWinn (1978) in their song analyses. Successive themes were labelled B, C, D ...
etc. The ratcheting sound appeared in the songs from the island of Hawaii(HI312 and HI315) and in the Bonin songs, but not in the Mexican or Ryukyuan
song, nor the Hawaiian sample from Maui (HI404). The A theme was thensearched for in the songs from Mexico and succeeding themes from that region
were identified according to the labels used for HI315, or were given new labels
if they did not appear in the Hawaii song. The Bonin themes were thenanalyzed using the labels identified in the Hawaiian and Mexican songs, withnew labels added as needed. Finally, the Ryukyuan themes were analyzed using
the labels available from the previous three regions, with one new label necessary in this last step. These procedures allowed for a comparison of theme
sequences as well as theme differences.
Sci. Rep. Cetacean Res.,
No. 1, 1990

8

HELWEG, HERMAN, YAMAMOTO AND FORESTELL
TABLE 2. SHARED AND UNIQUE SONG THEMES

Theme

Hawaii

Mexico

Bonin

A
B

x
x
x
x
x
x
x

x
x
x
x
x
x

x

c

D
E
Ft)

G

H
I
J
K
L
t)

Ryukyu

x
x
x
x
x
x

x
x

x

Ratchet sound.

RESULTS

Comparison of themes across regions
Themes from all of the song samples available in a region (Table 1) were combined to identify the themes present in that region, as shown in Table 2. A totalof 12 different themes (A-L) were identified across the four regions. Hawaiian
and Bonin song each contained seven themes and Mexican song six. Ryukyuan
song contained only three themes but, as was noted, all song samples were ofshort duration.
The data yielded a hierarchy of theme similarities across regions: Hawaii
and Mexico shared five themes and did not share three; Hawaii and Boninshared four and did not share three; Mexico and Bonin shared three and did notshare six; and Bonin and Ryukyu shared two and did not share six. The themespresent in Ryukyuan song did not overlap with any present in Hawaiian or
Mexican song. Three themes (A, D, and E) were common to Hawaiian,
Mexican and Bonin song; those three are referred to here as "pan-Pacific"
themes.
Fig. 3 shows sonographic records of these three pan-Pacific themes. The
versions from the various regions appear very similar. Frumhoff (1983, p.83)
defined "fundamental" themes as those "present in all songs of a least 90% of
the song sessions recorded in both that season and at least one contiguous
season." Whether the pan-Pacific themes can be termed "fundamental" in
Frumhoff's sense must await data from additional seasons and from additional
recordings.
The finding that no Ryukyuan theme appeared in the Hawaiian or Mexican
samples, and vice-versa, suggests that the whales visiting the Ryukyuan Islands
may be acoustically isolated from those visiting Hawaii or Mexico. At the sametime, the very short and likely incomplete song records from the Ryukyuan
Islands, the presence of two of three Ryukyuan themes in Bonin song, and theSci. Rep. Cetacean Res.,
No. 1, 1990

HUMPBACK WHALE SONGS

9

THEME A:kH'==:.:J~.1~~·~:::::=svz.':::=:;,;:§;·· __;__ _.;:::::::a:i'iiiii!l1'_1·~;
1

MEXICO :r=r

HAWAII

t.

;~,

BONIN

--:::.i:. . -THEMED:MEXICOi· f f- l't ~- :stdti

HAWAH

I

BONIN

I ;:::Jtt:

THEME E:MEXICOHAWAII

BONIN

2
3
SECONDS

4

5

Fig. 3. Comparison of sonograms of "pan-Pacific" themes shared by song recorded inJapan, Hawaii and Mexico. Component subphrases of each theme are shown once inthe figure although some may be repeated within any given phrase. Effective filter
bandwidth of Kay SonoGraph was 150 Hz. Vertical scale is in 1000 Hz increments.
Time is shown on horizontal axis.

partial overlap of Bonin with Hawaiian and Mexican song, weakens any case foracoustic isolation.
Fig. 4 shows sonographic records of the four themes (B, C, G and H) present in Hawaiian and/or Mexican song, but not in songs from the western
Pacific. Hawaiian and Mexican song share two of these themes (B and G).
Mexican song contains the unique theme H and Hawaiian song the uniquetheme C.
Fig. 5 shows theme F, the surface-ratchet sound, present in Hawaiian andBonin song but not in Mexican or Ryukyuan song. As we noted earlier, theratchet sound reliably predicted the surfacing of a singing whale in the Hawaiian
songs of 1989, as well as in songs of 1988. A ratcheting sound was also reported
by Winn and Winn (1978) as preceding surfacing of singing whales in the Puerto
Rico Silver Bank region. Sonograms available in Winn and Winn (1978) suggest
a similarity of the North Atlantic ratchet to the North Pacific sound, but it isSci. Rep. Cetacean Res.,
No. 1, 1990

10

HELWEG, HERMAN, YAMAMOTO AND FORESTELL
THEME B:kHz
4

MEXICO 2

HAWAII

THEME G:MEXICO~~- 1 i1j~w

HAWAIIUNIQUE MEXICAN THEMES:THEME H!f·!;

UNIQUE HAWAIIAN THEMES:THEME C

L=l!_::.···i·~'t:=.=::m;::~~·-·. ::==
1·" '1 · 15!}rt=a;
Jib ~='1&.
..........

2

3

SECONDS

Fig. 4. Sonograms of themes found in Mexican or Hawaiian song, or both, but not pre·sent in song from Japan, prepared as in Fig. 3.

THEME F:
kHz,.,,::~HAWAII

.., .

BONIN

.........

1· ...

.. ,·!•,•

0

2

3

4

5

SECONDS

Fig. 5. Sonograms of theme F, the "surface ratchet," common to Hawaiian and Boninsong, but not present in song from Mexico or Ryukyu, prepared as in Fig. 3.
Sci. Rep. Cetacean Res.,
No. 1, 1990

HUMPBACK WHALE SONGS

11

THEME I:
kHz

BONIN

:ir--.'-~;lL--~-,;--.-.. -j;-.-,,-!-J-'·'_j_)_:-l---,!!!-:;·_--._._------~-,-;-,t-

THEME J:RYUKYUUNIQUE BONIN THEMES:UNIQUE RYUKYUAN THEMES:THEME L

Fig. 6. Sonograms of themes found in Ryukyuan or Bonin song, or both, but notpresent in song from Hawaii or Mexico, prepared as in Fig. 3.

difficult to make a firm judgment from the quality of the available sonograms.
Fig. 6 describes four themes (I, J, K and L) present in Ryukyuan and/or
Bonin song, but not present in Hawaiian or Mexican song. Ryukyan and Boninsong shared themes I and J. Additionally, Bonin song contains one uniquetheme (K). Ryukyuan theme L was not present in RYU322 or RYU323, andwas produced only once in RYU319.

Comparisons of theme sequences within regions
Table 3 shows the sequence of themes in each song sample. The sequences arearranged to highlight corresponding theme sequences across the different recordings within each region. In Hawaii, the sequence DEFAB appears in thesong of Hl312 and of HI315. HI404 shares the sequence BCDE with HI315.
The short sequences BD and DE are shared by all three samples.
The Mexican song samples show an apparent lesser degree of correspondence across song samples. The longest shared sequence is BED, found in
MEX310B and MEX311. The two-theme sequence AB is found in all threesamples. Again, however, the short duration of MEX310A limits this type ofanalysis.
Sci. Rep. Cetacean Res.,
No. 1, 1990

12

HELWEG, HERMAN, YAMAMOTO AND FORESTELL
TABLE 3. THEME SEQUENCES OF EACH SAMPLE OF SONG FROM EACH REGION.
IDENTICAL THEMES OR THEME SEQUENCES WITHIN EACH REGION ARE ALIGNEDTO HIGHLIGHT SIMILARITIES.

HI312
HI315
HI404

B

F

A

B
B
B

c
c

D
D
D

E
E
E
B
B E
BI!

E

MEX310A
MEX310B
MEX311

B

E

D

H

G

A
A
A

BON414A
BON414B

E

D

E

F

A

D

L

J

RYU319RYU322RYU323

D

D

G

B

D
D
D

B

E
E

F
F

A
A

B
B

D

D

H

G

A

B
B

E
E

D
D

E

D
K

F
F

A
A

D
D

E
E

I
I

J
J

K

DI/

F
F

A
A

H

G

D
D

E
E

A

J

J
J
J

Note: Gaps between themes do not represent gaps in taping.
Actual breaks in taping are indicated by "//"The two Bonin samples share a six-theme sequence FADEIJ. The shorter
sequence FADE was found twice in BON414A and three times in BON414B.
The Ryukyuan song samples are short and generalizations are difficult.
Nevertheless, similarities are seen across samples in the sequence IJ, shared by
two song samples.
It is apparent that longer sequences (three or more themes) are not sharedacross the different regions, but several two-theme sequences are. Hawaii,
Mexico and Bonin song all share the sequences DE and the inversion ED.
Additionally Hawaii and Mexico share the sequence AB. Finally, Bonin and
Ryukyu share the sequence IJ.
Inverted theme sequences are rare. Payne et al. (1983) found only fivetheme inversions among 1196 two-theme sequences recorded during the 1976-77
winter season in Hawaii. In our within-region data, inversion of DE and ED is
relatively rare. Thus, in the Hawaiian songs, DE appears five times and ED
twice. Similarly, in Bonin song DE appears six times and ED twice. In Mexicansong, a reverse trend occurs: ED is the more common theme, appearing fivetimes while DE appears only once.
Fig. 7 graphs the two-theme transitions from Hawaii, Mexico and Boninfor those song sessions having the greatest number of theme sequences: HI315,
MEX311 and BON414B, respectively. The graphs reveal the general orderliness
in which themes are sequenced, especially for MEX311. Additionally, thefigures show the inversions of themes E and D in songs of individual whales
from Hawaii and Bonin and theme omissions by these same whales. Themeomissions, e.g., singing the sequence BD rather than BCD, are not unusual(Payne et al. 1983, Fig. 2) although omission of a fundamental theme is considered aberrant (Frumhoff, 1983).
Sci. Rep. Cetacean Res.,
No. 1, 1990

13

HUMPBACK WHALE SONGSBON 414bA

D/.3?\'2
F~V 1
\JE
1

4

\

I

~

\

_I
J'-2

I

Fig. 7. Theme transitions of selected samples from Mexico, Hawaii and Bonin
regions, based on data in Table 3. Frequency of transition is indicated within eacharrow. Solid lines indicate usual transition order; theme reversals are indicated bydashed lines.

Unique sound units
Despite the great variability of sounds produced during a singing session, theintroduction of new or unusual sounds is rare (Frumhoff, 1983). The basic"library" of sounds available to singers appears to remain relatively constant.
Variability and progressive change occur mainly by recombination of basic unitsor phrases. Novel sounds tend to become incorporated rapidly into the songs ofwhales in a common wintering ground (Payne et al., 1983). The presence of afew sound units in one wintering ground that do not appear in another wintering
ground, while at the same time the remaining sound units are shared, may indicate that those novel sounds were developed in the winter grounds themselves
when whales are acoustically isolated (because of the great distances involved)
from whales in other wintering grounds.
We found only three instances of sound units unique to a given wintering
ground in our song samples from Mexico, Hawaii and the Bonin Islands. The
Bonin song sample coded BON414A contains a unit in Theme I that appears to
be unique to this region. The unit is shown in Fig. 8a and can be described as a"pulsive scream" with a highly variable frequency structure. Furthermore,theme I contains a subphrase that is composed of a unit not found in either
Mexican or Hawaiian song. This is the series of J-shaped units shown in Fig. 8bwhich, together, comprise the central subphrase of theme I.
The sample of Mexican song coded as MEX311 contains a complex unit,
shown in Fig. 8c, that appears to be unique to the singers in Mexican waters.
This unit is found in theme H and is distinguished by a rapid change of harmonic structure between the initial and subsequent subunits, as well as by a
rapid traverse of frequency.
Sci. Rep. Cetacean Res.,
No. 1, 1990

14

HELWEG, HERMAN, YAMAMOTO AND FORESTELL
kHz
4

a.

_;

2

..~\

.\.'

0

b.

c.

0

2

3

4

5

SECONDS

Fig. 8. Unique sound units in different wintering areas. a. The "pulsive scream" from
Bonin theme I that is unique to the Bonin song samples. b. The J-shaped units that
may comprise the central subphrase of theme I in Bonin song. c. The complex unit
from Mexican theme H that is unique to the Mexican song samples.

· - - - - • 3 0 . 0_ _ _ _ _11'._rMEXICO
Fig. 9. The percentage of overlap of song themes from the five wintering areas, basedon the data of Table 2. The width of the lines connecting paired regions is
proportional to the percentage of overlap.

Sci. Rep. Cetacean Res.,

No. 1, 1990

HUMPBACK WHALE SONGS15DISCUSSION

The comparison of themes across the different regions revealed varying degreesof theme overlap. Using the theme structure shown in Table 2, the percentageof overlap of two regions can be calculated as the number of shared themes
divided by the total number of shared and unshared themes across the tworegions, multiplied by 100. Fig. 9 illustrates the results obtained with thismeasure for each pair of regions. The largest overlap occurred for Hawaiian and
Mexican song, then Hawaiian and Bonin song, then Mexican and Bonin song,and finally Bonin and Ryukyuan song. There was no overlap of Ryukyuan songwith song from Hawaii or Mexico.
As we noted earlier, the Ryukyuan song samples we obtained were of very
short duration, and it is probable that had longer samples been available morethemes would have been found. Hence, at this time no firm conclusions are
possible about the relationship between Ryukyuan song and songs from Hawaii
or Mexico. The relationship between Ryukyuan song and Bonin song is probably closer than suggested by the low percentge of overlap shown in Fig. 9. Of
the three Ryukyuan themes identified, two were also found in Bonin song.
Ryukyu may not be a true winter terminus for humpback whales but only atemporary way-station along the migration route to the Bonin Islands or topoints south, as was implied by Nishiwaki's (1959, 1960, 1962, 1966) data. In the
future, further, detailed analysis of longer samples of Bonin song can help toanswer questions about the degree to which whales visiting the Ryukyuan
islands are affiliated with whales visiting the Bonin Islands.
The relatively large overlap of Hawaiian and Mexican song confirms earlier
reports of Winn et al. (1981) and of Payne and Guinee (1983) of considerable
song similarity across these regions. Spectrograms published in Payne andGuinee (1983) show that the seven themes found in 1979 Mexican song overlapped totally the seven found in Hawaiian song in that same year. This result issimilar to our findings that five of six Mexican themes were found among theseven Hawaiian themes. Comparisons of the 1979 sonograms published by Payne
and Guinee (1983) with those available here do not show any obvious similarityof themes, indicating that the song evolved considerably over the 10-year interval. This degree of change is not unexpected based on other analyses of progressive song change over years. (Payne et al., 1983; Payne and Payne, 1985).
The overlap between Bonin and Hawaiian song and between Bonin and
Mexican song, especially the presence of the three pan-Pacific themes in thesongs of all three regions, suggests that whales in these wintering grounds are in
acoustic contact during some portion of their migratory cycle. The percentage ofoverlap of pairings of Mexico, Hawaii and Bonin song, as shown in Fig. 9,varies directly with the distance between these locations: approximately 3,160
km from Mexico to Hawaii, 3 ,940 km from Hawaii to Bonin, and 7 ,056 km from
Sci. Rep. Cetacean Res.,
No. 1, 1990

16

HELWEG, HERMAN, YAMAMOTO AND FORESTELL

Mexico to Bonin. The data thus suggest a decreasing degree of acoustic contactof the whales in these separated areas as a function of distance. The distanceseparating the winter grounds may not be the major variable determining song
similarities and differences, however, and the data on the limitation in propagation distances of song (Frankel et al., 1989; Payne and Guinee, 1983; Winn andWinn, 1978) make it unreasonable to assume that whales in one winter ground
could be listening to whales in another winter ground. More important variables
may be the degree of spatial separation of whales in the summer feeding
grounds, the spatial separation of the migration routes taken by whales journeying to the different winter grounds, and the degree to which migratory interchange occurs between summer grounds and between winter grounds.
Whales visiting Hawaii and Mexico are known to appear in some of thesame feeding sites in the summer, the western Gulf of Alaska, including Prince
William Sound, and southeast Alaska, in particular (Baker et al., 1986; Darlingand Jurasz, 1983), allowing for song exchange during the late Fall months whensome singing is heard (Matilla et al., 1987; Mcsweeney et al., 1989). Additionally, whales from the feeding grounds in Prince William Sound, the western
Gulf of Alaska, and southeast Alaska may share portions of their migrationroutes during a journey to Hawaii or Mexico, allowing for song exchange during
a time when singing has been heard (Tyack and Whitehead, 1983; Kaufman andJenkins, 1985). Also, there is some dispersion of whales from a common feedingsite to the different winter grounds of Hawaii and Mexico (Baker et al., 1986;
Perry, Mobley, Baker and Herman, 1988), so that a common late Fall songheard in a given feeding ground could appear in different winter grounds;
additionally, some convergence of song could occur after return of whales fromdifferent winter grounds to the common feeding grounds, which would manifest
itself in song similarity during the subsequent winter season. Finally, althoughapparently rare, visits between the Mexican and Hawaiian winter regions by indivisual whales during contiguous winter seasons has also been documented(Baker et al., 1986; Darling and Jurasz, 1983; Darling and McSweeney, 1985),
providing a further mechanism for song exchange, provided the song has not
drifted too far during the intervening year. We also noted earlier the one casereported thus far of a whale visiting both Mexico and Hawaii in a single winterseason.
It seems less likely that whales visiting the western Pacific winter grounds
share a migration route with whales visiting the central or eastern Pacificgrounds. Contact of Mexican/Hawaiian whales with Bonin whales may takeplace in the summer feeding grounds, however. Nishiwaki (1966) reported therecovery of six Discovery tags in the Ryukyuan Islands from humpback whales
marked in the eastern end of the Aleutian chain. This feeding region may beclose enough to the western Gulf of Alaska, a documented site to which somewhales return from Hawaii (Baker et al., 1986), to allow for acoustic contact.
Sci. Rep. Cetacean Res.,
No. 1, 1990

HUMPBACK WHALE SONGS

17

Thus at least three mechanisms-contact in the feeding grounds, common
migration routes, and interchange between winter sites by individuals-seem
available for song exchange between Hawaii and Mexico. In the least, the firstmechanism listed may also be available for song exchange between whales visiting Hawaii and the Bonin Islands. Our findings that the songs across the three
regions are not identical, that some themes are not shared, and that some unique
sound units occur in Mexican and Bonin song, suggest that acoustic contact
across these three principal regions-Hawaii, Mexico and the Bonin Islands-is
not complete, at least during the portion of the season when we sampled song.
A final consideration is the extent to which song similarity is correlatedwith genetic distance, and may therefore be an indicator of the separation ofstocks. Baker, Palumbi, Lambertsen, Weinrich, Calambokidis and O'Brien(1990) examined mitochondrial DNA differences among humpback whales in
the Farallon Islands near central California, the Hawaiian Islands, and southeast
Alaska in the North Pacific, and the Gulf of Maine in the North Atlantic. They
found the greatest genetic distance between the Gulf of Maine whales and thoseof the North Pacific, and considerably less disparity within regions of the North
Pacific. Particularly, there was virtually no difference between the Hawaiian
and southeast Alaska whales. It is interesting that photographic matches haveshown that a majority of the photo-identified whales from southeast Alaska
winter in Hawaii (Baker et al., 1986; Darling and Jurasz, 1983; Darling andMcsweeney, 1985; Perry et al., 1988). The genetic distance between the whalesof the Farallon Islands and those from Hawaii was greater than that between
Hawaii and southeast Alaska but less than that between the North Atlantic andany region of the North Pacific. Photo-identification data suggests that whales
from the Farallon Islands tend to winter in Mexico primarily (Calambokidis,
Steiger, Cubbage, Balcomb, Bloedel and Bockus, 1989). The analyses of song
differences in this paper, as well as earlier analyses by Payne et al. (1983) andWinn et al. (1981), reveal large song differences between North Atlantic and
Mexican/Hawaiian whales and, in this paper, some differences between Hawaii
and Mexico whales. Thus, genetic distance and song difference appear to bepositively correlated, giving some support to the thesis of Payne and Guinee(1983) that song differences may be an indicator of separate stocks. If their
thesis is correct, one would expect that mitochondrial DNA analyses of whales
in Japanese waters would reveal a genetic distance from Hawaiian whales atleast as great as that found between Hawaiian whales and those in the Farallon
Islands. Efforts to obtain miotochondrial DNA data from whales in Japanesewaters should thus prove fruitful for further understanding of stock separationand the relation of song differences to stocks. Additionally illuminating would
be more extensive photographic analyses of whales in Japanese waters to search
for individuals that might have appeared in other years in winter grounds to theeast or in summer grounds shared with whales visiting Hawaii or Mexico.
Sci. Rep. Cetacean Res.,
No. 1, 1990

18

HELWEG, HERMAN, YAMAMOTO AND FORESTELLACKNOWLEDGMENTS

We wish to thank the following people and organizations for their contributionof recordings of song: Tsuneo Nakamura and the Toba Aquairum for all samples
of Ryukyuan song; Ken Balcomb and Diane Claridge of the Center for Whale
Research, and Jorge Urban of Universidad Autonoma de Baja California Sur
for all samples of Mexican song: the Kewalo Basin Marine Mammal Laboratory
for the two samples of Hawaiian song obtained at South Kohala on the island of
Hawaii; and the Pacific Whale Foundation for the samples of Bonin song andthe sample of Hawaii song obtained in Maui. Recordings of Bonin song weremade possible through the cooperation and support of TV-12 Tokyo, NHK
Tokyo, and the Ogasawara Village Assembly. Songs recorded at South Kohala
and at Mexico were supported by grants from the Center for Field Research(Earthwatch) to L.M. Herman and A. Frankel of the Kewalo Basin Marine
Mammal Laboratory and to K. Balcomb of the Center for Whale Research.
Sonograms were made through the cooperation of Dr V. Condax of the Department of Linguistics of the University of Hawaii.
REFERENCESBAKER, C. S. and HERMAN, L. M. 1981. Migration and local movement of humpback whales through Hawaiian
waters. Can. J. Zool. 59: 460-469.
BAKER, C. S. and HERMAN, L. M. 1984. Aggressive behavior between humpback whales, Megaptera
novaeangliae, wintering in Hawaiian waters. Can. J. Zoo[. 62: 1922-1937.
BAKER, C.S., HERMAN, L.M., PERRY, A., LAWTON, W.S., STRALEY, J.M., WOLMAN, A.A., KAUFMAN, G.D.,
WINN, H.E., HALL, J.D., REINKE, J.M. and OsTMAN, J. 1986. Migratory movement and population
structure of humpback whales (Megaptera novaeangliae) in the Central and Eastern North Pacific.
Mar. Ecol. Prog. Ser. 31: 105-119.
BAKER, C. S., PALUMBI, S. R., LAMBERTSEN, R.H., WEINRICH, M. T., CALAMBOKIDIS, J. and O'BRIEN, S. J. 1990.
Influence of seasonal migration on geographical distribution of mitochondrial DNA haplotypes inhumpback whales. Nature 344: 238-240.
BROUGHTON, W. B. (1963). Glossarial index. pp. 824-910. In: R. G. Busnel (ed.) Acoustic behavior of animals. Elsevier, London.
CALAMBOKIDIS, J., STEIGER, G.H., CUBBAGE, J.C., BALCOMB, K.C., BLOEDEL, P. and BocKUS, D.W. 1989.
Abundance and distribution of blue and humpback whales in the Gulf of the Farallones. Abstract ofthe paper presented to the Eighth Biennial Conf. on the Biology of Marine Mammals, p.10, PacificGrove, CA, December 1989. 81pp.
CHITTLEBOROUGH, R. G. 1955. Aspects of reproduction in the male humpback whale, Megaptera nodosa(Bonna-terre). Austr. J. Mar. Fresh. Res. 6: 1-29.
CHITTLEBOROUGH, R. G. 1958. The breeding cycle of the female humpback whale Megaptera nodosa (Bonnaterre). Austr. J. Mar. Fresh. Res. 9: 1-18.
CHITTLEBOROUGH, R. G. 1965. Dynamics for 2 populations of the humpback whale, Megaptera novaeangliae(Borowski). Austr. J. Mar. Fresh. Res. 16: 33-128.
CHU, K. and HARCOURT, P. 1986. Behavioral correlations with aberrant patterns in humpback whale songs.
Behav. Ecol. Sociobiol. 19: 309-312.
DARLING, J. D. and JuRASZ, C. M. 1983. Migratory destinations of North Pacific humpback whales (Megaptera
novaeangliae). pp. 359-368. In: R. Payne (ed.) Communication and behavior of whales. Westview
Press, Boulder. 643pp.

Sci. Rep. Cetacean Res.,
No. 1, 1990

HUMPBACK WHALE SONGS19DARLING, J.D., GrnsoN, K.M. and SILBER, G.K. 1983. Observations on the abundance and behavior of
humpback whales (Megaptera novaeangliae) off West Maui, Hawaii, 1977-79. pp. 201-222. In: R.
Payne (ed.) Communication and Behavior of Whales. Westview Press, Boulder. 643pp.
DARLING, J.D. and McSwEENEY, D.J. 1985. Observations on the migrations of North Pacific humpback
whales (Megaptera novaeangliae). Can. J. Zool. 63: 308-314.
DAWBIN, W.H. 1966. The seasonal migratory cycle of humpback whales. pp. 145-169. In: K.S. Norris (ed.)
Whales, Dolphins, and Porpoises. University of California Press, Berkeley. 788pp.
FRANKEL, A.S., CLARK, c. w., HERMAN, L.M., GABRIELE, C.M., HOFFHINES, M.A., FREEMAN, T.R. and PATTERSON, B. K. 1989. Acoustic location and tracking of wintering humpback whales (Megaptera
novaeangliae) off South Kohala, Hawaii. Abstract of the paper presented to the Eighth Biennial Conf.
on the Biology of Marine Mammals, p.21, Pacific Grove, CA, December 1989. 81pp.
FRUMHOFF, P. 1983. Aberrant songs of humpback whales (Megaptera novaeangliae): Clues to the structure of
humpback songs. pp. 81-128. In: R. Payne (ed.) Communication and Behavior of Whales. Westview
Press, Boulder. 643pp.
GLOCKNER, D. A. 1983. Determining the sex of humpback whales (Megaptera novaeangliae) in their naturalenvironment. pp. 447-464. In: R. Payne (ed.) Communication and Behavior of Whales, Westview
Press, Boulder. 643pp.
GLOCKNER, D. A. and VENUS, S. C. 1983. Identification, growth rate, and behavior of humpback whale(Megaptera novaeangliae) cows and calves in the waters of Maui, Hawaii, 1977-79. pp. 223-258. In: R.
Payne (ed.) Communication and Behavior of Whales. Westview Press, Boulder. 643pp.
GUINEE, L.N., CHU, K. and DORSEY, E.M. 1983. Changes over time in the songs of known individual
humpback whales (Megaptera novaeangliae). pp. 59-80. In: R. Payne (ed.) Communication and Behavior of Whales. Westview Press, Boulder. 643pp.
HELWEG, D. A. 1989. Diurnal and seasonal patterns of behavior and abundance of humpback whales (Megaptera novaeangliae) in Hawaiian waters. Unpublished Master's thesis, University of Hawaii, Honolulu.
133pp.
HERMAN, L.M. and ANTINOJA, R.C. 1977. Humbpack whales in the Hawaiian breeding waters: populationand pod characteristics. Sci. Rep. Whales Res. Inst., Tokyo 29: 59-85.
HERMAN, L.M., FoRESTELL, P.H. and ANTINOJA, R. C. 1980. The 1976177 migration of humpback whales into
Hawaiian waters: composite description. Springfield, VA: NTIS, PB80-162332. 55pp.
JOHNSON, J.H. and WOLMAN, A.A. 1984. The humpback whale, Megaptera novaeangliae. Mar. Fish. Rev.
46: 30-37.
KAUFMAN, G.D. and JENKINS, P.F. 1985. Comparison of Australian and Hawaiian humpback whale songs.
Abstract of the paper presented to the Sixth Biennial Conf. on the Biology of Marine Mammals. Vancouver, Canada, November 22-26 1985.
KELLOGG, R. 1929. What is known about the migrations of some of the whalebone whales. Annual Reports of
the Smithsonian Institution for 1928, 467-494.
LEVENSON, C. 1972. Characteristics of sounds produced by humpback whales (Megaptera novaeangliae).
NAVOCEANO Technical Note No. 7700-6-72. Washington, D.C. 20pp.
MATILLA, D.K., Gu1NEE, L.N. and MAYO, C.A. 1987. Humpback whale songs on North Atlantic feeding
grounds. J. Mammal. 68: 880-883.
McSwEENEY, D.J., CHU, K. C., DOLPHIN, W.F. and GuINEE, L.N. 1989. North Pacific humpback whale songs:
A comparison of southeast Alaskan feeding ground songs with Hawaiian wintering ground songs. Mar.
Mamm. Sci. 5: 139-148.
MoBLEY, J.R., HERMAN, L.M. and FRANKEL, A.S. 1988. Responses of wintering humpback whales (Megaptera novaeangliae) to playback of recordings of winter and summer vocalizations and of synthetic
sound. Behav. Ecol. Sociobiol. 23: 211-223.
NEMOTO, T. 1978. Humpback whales observed within the continental shelf waters of the Eastern Bering Sea.
Sci. Rep. Whales Res. Inst., Tokyo 30: 245-247.
NIKULIN, I. P. 1946. Distribution of cetaceans in seas surrounding the Chukchi Peninsula, Vol. 22 (pp. 25557). U.S. Naval Oceanographic Office, Washington, D.C. (translated in 1969).
NISHIWAKI, M. 1959. Humpback whales in Ryukyuan waters. Sci. Rep. Whales Res. Inst., Tokyo 14: 49-87.
NISHIWAKI, M. 1960. Ryukyuan humpback whaling in 1960. Sci. Rep. Whales Res. Inst., Tokyo 15: 1-15.
NISHIWAKI, M. 1962. Ryukyuan whaling in 1961. Sci. Rep. Whales Res. Inst., Tokyo 16: 19-28.

Sci. Rep. Cetacean Res.,
No. 1, 1990

20

HELWEG, HERMAN, YAMAMOTO AND FORESTELLNISHIWAKI, M. 1966. Distribution and migration of the larger cetaceans in the North Pacific as shown byJapanese whaling results. pp. 171-191. In: K.S. Norris (ed.) Whales, Dolphins, and Porpoises. University of California Press, Berkeley. 789pp.
PAYNE, K. and PAYNE, R. 1985. Large scale changes over 19 years in the songs of humpback whales in Bermuda. Z. Tierpsychologie 68: 89-114.
PAYNE, K., TYACK, P. and PAYNE, R. 1983. Progressive changes in the songs of humpback whales (Megaptera
novaeangliae): A detailed analysis of two seasons in Hawaii. pp. 9-58. In: R. Payne (ed.) Communication and Behavior of Whales. Westview Press, Boulder 643pp.
PAYNE, R.S. 1978. Behavior and vocalizations of humpback whales (Megaptera sp.). pp. 56-78. In: K.S.
Norris and R.R. Reeves (eds) Report on a workshop on problems related to humpback whales(Megaptera novaeangliae) in Hawaii, NTIS, PB-280794, Report No. MMC-77/03. Springfield, VA.
90pp.
PAYNE, R. and GUINEE, L.N. 1983. Humpback whale (Megaptera novaeangliae) songs as an indicator of"stocks". pp. 333-358. In: R. Payne (ed.) Communication and Behavior of Whales. Westview Press,
Boulder. 643pp.
PAYNE, R. and McvAY, S. 1971. Songs of humpback whales. Science 173: 585-597.
PAYNE, R. and WEBB, D. 1971. Orientation by means of long-range acoustic signaling in baleen whales.
Ann. N. Y. Acad. Sci. 188: 110-141.
PERRY, A., MOBLEY, J.R., Jr., BAKER, c.s. and HERMAN, L.M. (eds) 1988. Humpback whales of the central
and eastern North Pacific: A catalog of individual identification photographs. Sea Grant Miscellaneous
Report UNIHI-SEAGRANT-MR-88-02, University of Hawaii. 233pp.
RICE, D. W. 1978. The humpback whale in the North Pacific: Distribution, exploitation, and numbers.
pp. 45-53. In: K.S. Norris and R.R. Reeves (eds) Report on a workshop on problems related to
humpback whales (Megaptera novaeangliae) in Hawaii, NTIS, PB-280794, Report No. MMC-77/03.
Springfield, VA: 90pp.
THOMPSON, P. 0. and FRIEDL, W. A. 1982. A long term study of low frequency sounds from several species ofwhales off Oahu, Hawaii. Cetology 45: 1-19.
ToMILIN, A. G. 1967. Mammals of the U.S.S.R. and adjacent countries: Cetacea. Israel Program for Scientific
Translations, Jerusalem. 717pp.
TOWNSEND, C. H. 1935. Tiie distribution of certain whales as shown by logbook records of American
whaleships. Zoologica, N. Y. 19: 1-50.
TYACK, P. 1981. Interactions between singing Hawaiian humpback whales and conspecifics nearby. Behavi.
Ecol. Sociobiol. 8: 105-116.
TYACK, P. 1983. Differential response of humpback whales, Megaptera novaeangliae, to playback of song orsocial sounds. Behav. Ecol. Sociobiol. 13: 49-55.
TYACK, P. and WHITEHEAD, H. 1983. Male competition in large groups of wintering humpback whales.
Behaviour 83: 132-154.
URBAN, J.R. and AGUAYO, A.L. 1987. Spatial and seasonal distribution of the humpback whale, Megaptera
novaeangliae, in the Mexican Pacific. Mar. Mamm. Sci. 3: 333-344.
WINN, H.E. and WINN, L. K. 1978. The song of the humpback whale Megaptera novaeangliae in the West Indies. Mar. Biol. 47: 97-114.
WINN, H.E., BISCHOFF, W.L. and TARUSKI, A. G. 1973. Cytological sexing of cetacea. Mar. Biol. 23: 343-346.
WINN, H.E., THOMPSON, J. T., CUMMINGS, w. C., HAINS, J., HUDNALL, J., HAYS, J. and STEINER, w. w. 1981.
Song of the humpback whale: population comparisons. Behav. Ecol. Sociobiol. 8: 41-46.

Sci. Rep. Cetacean Res.,
No. 1, 1990