30
w.w.L. Au
Ala
oW",:10
- - - - - ,
2IXl
r----- 400
. . . . . . - - - - oW-:1o
- - - - . - - - - - -
llIll
6.0
4.0
2.0
kHz:
s
s
2.0
2.Q
4.0
4.0
Alb
6.0
6.0
8.0
10.0
FIGURE 1.12. Examples of a portion of the time waveforms of ratchet sounds of
humpback whales and the corresponding spectrograms. (After Mercado 1995.)
by Ljungblad et al. (1982) and by Cummings and Holliday (1987) may be
due to bowhead whales changing their songs from year to year.
The sounds from fin whales, Balaenoptera physalus, include single 20-Hz
pulses, irregular series of 20-Hz pulses, and stereotyped 20-Hz signal bouts
of repetitive sequences of 20-Hz pulses (Watkins 1981). The 20-Hz signals
are emitted in bouts that can last for hours. The pulse intervals in a bout
are very regular. In general, signals are produced in a relatively regular
sequence of repetitions at intervals ranging from about 7 to 26s, with bouts
that can last as long as 32.5 h. During a bout, periodic rests averaged about
115 s at roughly lS-min intervals and sometimes longer irregular gaps
between 20 and 120min were observed. There was also some variability in
the 20-Hz signals in that they were never exactly replicated.
The songs of the blue whales (B. musculus) have been observed by a
number ofresearchers (Thompson et al. 1987; Alling et al. 1991; McDonald
w.w.L. Au
Ala
oW",:10
- - - - - ,
2IXl
r----- 400
. . . . . . - - - - oW-:1o
- - - - . - - - - - -
llIll
6.0
4.0
2.0
kHz:
s
s
2.0
2.Q
4.0
4.0
Alb
6.0
6.0
8.0
10.0
FIGURE 1.12. Examples of a portion of the time waveforms of ratchet sounds of
humpback whales and the corresponding spectrograms. (After Mercado 1995.)
by Ljungblad et al. (1982) and by Cummings and Holliday (1987) may be
due to bowhead whales changing their songs from year to year.
The sounds from fin whales, Balaenoptera physalus, include single 20-Hz
pulses, irregular series of 20-Hz pulses, and stereotyped 20-Hz signal bouts
of repetitive sequences of 20-Hz pulses (Watkins 1981). The 20-Hz signals
are emitted in bouts that can last for hours. The pulse intervals in a bout
are very regular. In general, signals are produced in a relatively regular
sequence of repetitions at intervals ranging from about 7 to 26s, with bouts
that can last as long as 32.5 h. During a bout, periodic rests averaged about
115 s at roughly lS-min intervals and sometimes longer irregular gaps
between 20 and 120min were observed. There was also some variability in
the 20-Hz signals in that they were never exactly replicated.
The songs of the blue whales (B. musculus) have been observed by a
number ofresearchers (Thompson et al. 1987; Alling et al. 1991; McDonald