133
5.4.7 Killer Whale (Orcinus orca)
Killer whales are widely distributed throughout all ocean basins, especially in areas of
high ocean productivity (Ford 2009). This species presents a sexual dimorphism, which
males develop larger total length (nine meters) and appendages than females (seven
meters) (Bastida et al. 2007; Ford 2009). In Brazilian waters sightings of killer whale
are more frequent in coastal waters of the southeast; however this species is known to
frequently depredate the catch of longline fisheries near the shelf break and beyond in
southern Brazil (Secchi and Vaske 1998; Dalla Rosa and Secchi 2007) (Fig. 5.21).
Killer whales have complex communication strategies (Filatova et al. 2012).
Signals, such as whistles and pulsed calls, are probably culturally transmitted
through vocal learning (Ford 1991; Deecke et al. 2002; Foote et al. 2006), and are
highly stereotyped (Ford 1991; Riesch et al. 2006). When compared to pulsed calls,
whistles are highly modulated signals and have lower sound pressure levels and
higher fundamental frequencies (Ford 1989; Thomsen et al. 2001; Riesch et al. 2006).
Discussions on the ecological role and possible ecological function of high frequency whistles (HFWs) produced by killer whales have recently emerged in the
literature (Samarra et al. 2010, 2015; Simonis et al. 2012; Filatova et al. 2012;
Trickey et al. 2014). This signal could be used for navigation (Simonis et al. 2012)
or for private communication (Filatova et al. 2012).
Recent study on the western south Atlantic have described the acoustic parameters of killer whale whistles and highlighted the occurrence of high frequency whistles (Andriolo et al. 2015). The high frequency whistles (Fig. 5.22A) were highly
stereotyped and were modulated mostly at ultrasonic frequencies. Compared to
other contour types (Fig. 5.22B), the high frequency whistles are characterized by
higher bandwidths, shorter durations, fewer harmonics, and higher sweep rates
(Andriolo et al. 2015) (Table 5.1).
Fig. 5.21 Killer whale photographed in the western South Atlantic Ocean off the Brazilian coast
(Reproduced with permission of Rodrigo Genoves)
5 Marine Mammal Bioacustics Using Towed Array Systems in the Western South…
5.4.7 Killer Whale (Orcinus orca)
Killer whales are widely distributed throughout all ocean basins, especially in areas of
high ocean productivity (Ford 2009). This species presents a sexual dimorphism, which
males develop larger total length (nine meters) and appendages than females (seven
meters) (Bastida et al. 2007; Ford 2009). In Brazilian waters sightings of killer whale
are more frequent in coastal waters of the southeast; however this species is known to
frequently depredate the catch of longline fisheries near the shelf break and beyond in
southern Brazil (Secchi and Vaske 1998; Dalla Rosa and Secchi 2007) (Fig. 5.21).
Killer whales have complex communication strategies (Filatova et al. 2012).
Signals, such as whistles and pulsed calls, are probably culturally transmitted
through vocal learning (Ford 1991; Deecke et al. 2002; Foote et al. 2006), and are
highly stereotyped (Ford 1991; Riesch et al. 2006). When compared to pulsed calls,
whistles are highly modulated signals and have lower sound pressure levels and
higher fundamental frequencies (Ford 1989; Thomsen et al. 2001; Riesch et al. 2006).
Discussions on the ecological role and possible ecological function of high frequency whistles (HFWs) produced by killer whales have recently emerged in the
literature (Samarra et al. 2010, 2015; Simonis et al. 2012; Filatova et al. 2012;
Trickey et al. 2014). This signal could be used for navigation (Simonis et al. 2012)
or for private communication (Filatova et al. 2012).
Recent study on the western south Atlantic have described the acoustic parameters of killer whale whistles and highlighted the occurrence of high frequency whistles (Andriolo et al. 2015). The high frequency whistles (Fig. 5.22A) were highly
stereotyped and were modulated mostly at ultrasonic frequencies. Compared to
other contour types (Fig. 5.22B), the high frequency whistles are characterized by
higher bandwidths, shorter durations, fewer harmonics, and higher sweep rates
(Andriolo et al. 2015) (Table 5.1).
Fig. 5.21 Killer whale photographed in the western South Atlantic Ocean off the Brazilian coast
(Reproduced with permission of Rodrigo Genoves)
5 Marine Mammal Bioacustics Using Towed Array Systems in the Western South…