434
2001). A different interpretation of the function of the song involving a cooperative
male behavior during group formation in discussed by Darling et al. (2006).
15.4.3 Chorus Behavior
The chorus behavior is described as a part of the complex leking, where males tend
to defend resources to which females are attracted, in this last case gain from stimulus pooling by displaying together and providing greater attraction for females
(Krebs and Davies 1993). This strategy has been largely studied for ungulate, bats
and frogs (revised in Krebs and Davies 1993).
While much attention has been given to the characteristics of songs, few studies
go into the chorus behavior by multiple humpback whales (Au et al. 2000). Thompson
and Friedl (1982) were the first to mention chorusing for the humpbacks in Hawaii,
finding seasonality and daytime preference for chorusing in a breeding area.
Au et al. (2000) described spectral features as well temporal utilization of the
chorus behavior in the humpbacks during the 1998 Hawaiian season, showing spectral peaks at 315 and 630 Hz. Their data also indicated a diurnal pattern in the sound
pressure level, with levels at night significantly louder than the daytime levels,
attributing different mating strategies to the species during a night and day scale, in
which competitive groups are more frequent during the day, requiring more visual
contact, while chorusing are more frequent during the night time.
Our study brought for the first time the chorus perspective to the humpback
whale acoustic ecology in the Brazilian waters. The higher occurrence of chorus
found in the Abrolhos Bank could indicate that this behavior should act as a trigger
to the female choice as described for the terrestrial leks (Alcock 1993; Krebs and
Davies 1993). Listening to an intense chorus, females would be guided to a good
area concerning the search for a mate. Additionally, we are in accordance to the Au
et al. (2000) suggestion of the viability of using different levels of chorusing to
monitor and estimate the relative abundance of male humpback whales in the
Brazilian breeding ground.
Summarizing, there are numerous hypotheses on the implications of the humpback whale song, many of which are not mutually exclusive. The fact is that many
aspects of the humpback whale song components remain unknown, such as what
are the reasons to keep for a longer time some components instead other and what
kind of significance it has on reproductive success over time.
The humpback whale, as a migratory animal, requires a broad geographic scale to
develop essential activities such as feeding and breeding, for consequence implying
on a huge logistical structure to access their habits in accordance to such large scale.
The Ocean is a challenging environment to man, in the path of an ecological
comprehension and global vision. Therefore, we still know very few about the
whole implication of the humpback whale role in this broad oceanic scale. Perhaps
in a near future, besides with the necessary technology to the understanding of oceM.R. Rossi-Santos
2001). A different interpretation of the function of the song involving a cooperative
male behavior during group formation in discussed by Darling et al. (2006).
15.4.3 Chorus Behavior
The chorus behavior is described as a part of the complex leking, where males tend
to defend resources to which females are attracted, in this last case gain from stimulus pooling by displaying together and providing greater attraction for females
(Krebs and Davies 1993). This strategy has been largely studied for ungulate, bats
and frogs (revised in Krebs and Davies 1993).
While much attention has been given to the characteristics of songs, few studies
go into the chorus behavior by multiple humpback whales (Au et al. 2000). Thompson
and Friedl (1982) were the first to mention chorusing for the humpbacks in Hawaii,
finding seasonality and daytime preference for chorusing in a breeding area.
Au et al. (2000) described spectral features as well temporal utilization of the
chorus behavior in the humpbacks during the 1998 Hawaiian season, showing spectral peaks at 315 and 630 Hz. Their data also indicated a diurnal pattern in the sound
pressure level, with levels at night significantly louder than the daytime levels,
attributing different mating strategies to the species during a night and day scale, in
which competitive groups are more frequent during the day, requiring more visual
contact, while chorusing are more frequent during the night time.
Our study brought for the first time the chorus perspective to the humpback
whale acoustic ecology in the Brazilian waters. The higher occurrence of chorus
found in the Abrolhos Bank could indicate that this behavior should act as a trigger
to the female choice as described for the terrestrial leks (Alcock 1993; Krebs and
Davies 1993). Listening to an intense chorus, females would be guided to a good
area concerning the search for a mate. Additionally, we are in accordance to the Au
et al. (2000) suggestion of the viability of using different levels of chorusing to
monitor and estimate the relative abundance of male humpback whales in the
Brazilian breeding ground.
Summarizing, there are numerous hypotheses on the implications of the humpback whale song, many of which are not mutually exclusive. The fact is that many
aspects of the humpback whale song components remain unknown, such as what
are the reasons to keep for a longer time some components instead other and what
kind of significance it has on reproductive success over time.
The humpback whale, as a migratory animal, requires a broad geographic scale to
develop essential activities such as feeding and breeding, for consequence implying
on a huge logistical structure to access their habits in accordance to such large scale.
The Ocean is a challenging environment to man, in the path of an ecological
comprehension and global vision. Therefore, we still know very few about the
whole implication of the humpback whale role in this broad oceanic scale. Perhaps
in a near future, besides with the necessary technology to the understanding of oceM.R. Rossi-Santos