Interspecific cetacean interactions during the breeding season of humpback whale (Megaptera novaeangliae) on the north coast of Bahia State, Brazil

Abstract

The large majority of cetacean interspecific studies report only on dolphin interactions, while studies on interactions between odontocete and mysticete are less common. The present work aims to report on sightings of cetacean interactions, during the breeding season of humpback whales(Megaptera novaeangliae), along 370 km of the Bahia State, north-eastern Brazil, addressing aspects of cetacean distribution and behaviour. During 7 seasons (2000–2006), a total of 230 research cruises were performed, in which 38 events of interactions among humpback whales and other cetaceans(Tursiops truncatus, Steno bredanensis, Peponocephala electraandBalaenoptera acutorostrata)were observed, plus another 5 encounters without the whale's presence, includingT. truncatus, S. bredanensis, P. electra, Stenella clymeneandStenella attenuata. Our results confirm the occurrence of multiple cetacean species in the Bahia State, being the first study in the world to report on a large range of interactions involving another 4 cetacean species, grouped with up to 3 mixed species per sighting, with humpback whales in their annual breeding ground.

Cetacean sightings, mixed-species assemblages and the easternmost record of Indopacetus pacificus from the northern Indian ocean

“…The first was of interest due to four species being in association with each other in a single group. Mixed-species associations involving delphinids including Stenella species, Tursiops species and Globicephala species are not unusual and they have been reported from several areas of the worlds' oceans (Querouil et al, 2008;Rossi-Santos et al, 2009) including areas around the Maldive Islands and Sri Lanka in the tropical Indian Ocean Anderson, 2005;Ilangakoon, 2012b). However, most such sightings contained two or three species at most while the present sighting included four species with three Stenella species and one Tursiops species.…”

Life history told by a whale-louse: a possible interaction of a southern right whale Eubalaena australis calf with humpback whales Megaptera novaeangliae

“…observ.). Reports about interactions between two mysticetes species are less common than interactions between mysticetes and odontocetes [26,27].…”

Marine Mammals of the Gulf of Mexico

“…For instance, bottlenose dolphins have been recorded to associate with more than 20 different cetaceans (Ballance 2009), including much larger species such as the humpback whale (Rossi-Santos et al 2009). Spotted and spinner dolphins occur regularly in mixed schools, especially in the eastern tropical Pacific.…”