20.10.2018 – From Bottlenose to Bottlenose

What a journey! I had a small group of guests on board our traditional boat this morning, that were obviously set on observing cetaceans in the wild. We set our course East before heading back up West against the impending swell and rainfall coming in from Ponta do Pargo and eventually located a curious group of around 25 Bottlenose dolphins (Tursiops truncatus). Many of the animals were busy hunting but a few larger animals and some calves spent a great deal of time at our bow, occasionally glancing up at us. We all had to hold on tight as the boat rocked up and down with the swell but our marvelous captain, Sr. Luis, had it all under control.

Bottlenose dolphins, however, are not all the same. In fact, scientists have long been struggling with the taxonomy of the Bottlenose dolpin and, so far, the IUCN ha recognized three species; the Common Bottlenose dolphin (Tursiops truncatus), the Indo-Pacific Bottlenose dolphin (Tursiops aduncus) and the Burrunan dolphin (Tursiops australis). The different species and subspecies of Bottlenose dolphins are segregated by their distiribution, so adapting to different environmental conditions may have created this genetic variation. Generally, Bottlenose dolphins are also extremely altruistic towards other cetacean species and are often observed interacting or engaging in mating behaviour with them. As a result, several hybrids of Bottlenose dolphins exist both in captivity and in the wild including the famous Wolphin, resulting from hybridizations with False orcas (Pseudorca crassidens) as well as hybrids with Atlantic spotted dolphins (Stenella frontalis). Hybridizations with Common dolphins and Rough-toothed dolphins (Steno bredanensis) also occurred in captivity but have not yet been reported in the wild.

As for Madeira, here we are able to encounter the two ecotypes of Bottlenose dolphins that are present in the Atlantic; the partially resident population of small, grey offshore-type Bottlenose dolphins and the large, dark colored oceanic-types.  If we keep a sharp-lookout, maybe we’ll even be able to enjoy a sighting with a hybrid one day. For now, we are happy about the company of our residents, especially on a day where weather conditions did not make finding cetaceans easy for our team. Our speedboat found another group of Bottlenose dolphins in the far Southeast of the island, near Funchal. Unfortunately, the group aboard our Ribeira Brava in the afternoon returned to the marina with no sighting of cetaceans despite the extensive efforts of our crew.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Bottlenose dolphins

15:00 No sighting

Stenella

10:00 Bottlenose dolphins