423
intense, suggesting the proximity to our boat. This animal presented long dives,
being the maximum value registered for the total sample of 780 s (13 min), and
performed the same fluke exhibition than the other observed males.
The smallest dive range was registered for FeCa pairs (maximum of
132 s–2,2 min). Couples were the second category in long dive patterns (2–660 s)
and the first in number of measurements larger than 100 s (n = 88) (Table 15.2).
15.3.5 Bioacoustics
15.3.5.1 Acoustic Parameters
Including the year 2010 in the acoustic sample, a 6 years (2005–2010) recording
period was obtained, in effort of more than 50 h. From these raw data, we selected
“type” songs from each sampled year, for both areas of Abrolhos Bank and the
North Coast, chosen by containing all the characteristic phrases of the song from
that year, as well by presents the best signal to noise ratio. In some years, like 2007,
more than one song was selected, produced at different time during the breeding
season, due to its high quality to extract additional acoustic information.
We measured a sample of 2868 component notes to describe the acoustic parameters of the humpback whale song in the Brazilian breeding ground. Data showed a
wide frequency variation, typical from the long and complex humpback whale song,
ranging from 20 Hz to the top of sampling rate (24,000 Hz), short duration notes
(mean = 1,06 s) and sound energy from 60 to 130 dB re SNR (Table 15.3). However
some features are remarkable, such as the mean central frequency at low frequency
(596 Hz) (Fig. 15.15) and the intense sound energy putted into sound transmission
(mean = 105 dB).
Table 15.2 Summary of humpback whale dive time from the study area in the Brazilian coast
between 2008 and 2009*
Group
structure
# Groups
Depth
range (m)
(D.O.)
(min)
(D.P)
range (s)
Mean range
D.P > 100 s # measur.
# measur.
> 100 s
Alone
males
21
8,7–126
977
2–780
134,3–780
278
59
Couples
18
49–126
810
2–660
125,6–540
389
88
FeCa
pairs
3
–
120
5–132
116–166,3
59
7
FeCa-E1
10
66–155
500
2–349
122–479,5
230
31
Total
52
8,7–155
2407
2–780
956
185
*Definitions: (D.O.- minutes) = Direct Observation (the time spent observing humpback whale
groups); (D.P. range – seconds) = Dive Pattern – the time whales spent underwater; (Mean range
D.P > 100 s) = mean number of Dive Patterns larger than 100 s; (# of measur.) = number of dive
measurements; (# measure. > 100 s) = number of dive measurements larger than 100 s; (Fe-Ca
pairs) = female and calf pairs; (FeCa-E1) = female and calf pairs plus one escort male
15 The Spreading Message in a Noisy World: Song Behavior and Acoustic Ecology…
intense, suggesting the proximity to our boat. This animal presented long dives,
being the maximum value registered for the total sample of 780 s (13 min), and
performed the same fluke exhibition than the other observed males.
The smallest dive range was registered for FeCa pairs (maximum of
132 s–2,2 min). Couples were the second category in long dive patterns (2–660 s)
and the first in number of measurements larger than 100 s (n = 88) (Table 15.2).
15.3.5 Bioacoustics
15.3.5.1 Acoustic Parameters
Including the year 2010 in the acoustic sample, a 6 years (2005–2010) recording
period was obtained, in effort of more than 50 h. From these raw data, we selected
“type” songs from each sampled year, for both areas of Abrolhos Bank and the
North Coast, chosen by containing all the characteristic phrases of the song from
that year, as well by presents the best signal to noise ratio. In some years, like 2007,
more than one song was selected, produced at different time during the breeding
season, due to its high quality to extract additional acoustic information.
We measured a sample of 2868 component notes to describe the acoustic parameters of the humpback whale song in the Brazilian breeding ground. Data showed a
wide frequency variation, typical from the long and complex humpback whale song,
ranging from 20 Hz to the top of sampling rate (24,000 Hz), short duration notes
(mean = 1,06 s) and sound energy from 60 to 130 dB re SNR (Table 15.3). However
some features are remarkable, such as the mean central frequency at low frequency
(596 Hz) (Fig. 15.15) and the intense sound energy putted into sound transmission
(mean = 105 dB).
Table 15.2 Summary of humpback whale dive time from the study area in the Brazilian coast
between 2008 and 2009*
Group
structure
# Groups
Depth
range (m)
(D.O.)
(min)
(D.P)
range (s)
Mean range
D.P > 100 s # measur.
# measur.
> 100 s
Alone
males
21
8,7–126
977
2–780
134,3–780
278
59
Couples
18
49–126
810
2–660
125,6–540
389
88
FeCa
pairs
3
–
120
5–132
116–166,3
59
7
FeCa-E1
10
66–155
500
2–349
122–479,5
230
31
Total
52
8,7–155
2407
2–780
956
185
*Definitions: (D.O.- minutes) = Direct Observation (the time spent observing humpback whale
groups); (D.P. range – seconds) = Dive Pattern – the time whales spent underwater; (Mean range
D.P > 100 s) = mean number of Dive Patterns larger than 100 s; (# of measur.) = number of dive
measurements; (# measure. > 100 s) = number of dive measurements larger than 100 s; (Fe-Ca
pairs) = female and calf pairs; (FeCa-E1) = female and calf pairs plus one escort male
15 The Spreading Message in a Noisy World: Song Behavior and Acoustic Ecology…