Permanent resident of the Nosy Be coasts, the humpback dolphin is distinguished by its very pronounced hump just in front of the dorsal fin. It prefers shallow coastal waters (less than 25 meters), and is distributed over the majority of the coasts of the Indian Ocean. Swimming slowly and in small groups of 3 to 15 individuals, often mixing with the Tursiops, it is however very rarely approached, but gratifies us sometimes with beautiful acrobatics.
Humpback dolphin à Nosy Be
When can we sight humpback dolphins in Nosy Be?
Les dauphins à bosse restent à l’année autour de Nosy Be, il est donc possible de les voir à chacune des sorties. Ils restent en effet à l’intérieur de la baie, assez proche – voire très proche – des côtes. Nous les observons donc lors des départs ou retour des excursions, et parfois lors de notre arrivée à Nosy Iranja.
What do they feed on?
Le dauphin à bosse de l’Indo-Pacifique se nourrit de poissons d’estuaire et de récif, de crustacés et de mollusque. Il peut chasser individuellement comme collectivement, et la chasse se pratique en se servant de l’écholocation.
Living in shallow areas, it probes only on very short intervals, between 30 seconds and 2 minutes.
How tall are they?
Humpback dolphins can reach more than 3 meters for adult males.
They are massive and robust dolphins, which regularly exceed 300 kg.
Are humpback dolphins common around the world?
Living close to the coast and moving relatively slowly, humpback dolphins were largely victims of the development of maritime traffic, resulting in collisions often fatal. In addition, many regions of the world practice, or have practiced, dolphin hunting, which has decimated populations around the world. If no figures are currently available, it seems that this species is largely threatened with extinction.
A study is in progress in Nosy Be, led by Dr. Kiszka of Florida International University, following work done 10 years ago by Dr. Cerchio, to compare the number and distribution of humpback dolphins around Nosy Be.
Do they mix with other species?
It is indeed common to see humpback dolphins accompanied by bottlenose dolphins.