22.07.2018 – Stenella fan

We set out on a flat ocean and cruised along the coast on our traditional boat before braving the higher swell out at sea in our search for cetaceans. Our spotter informed us of a group of dolphins moving swiftly around eight nautical miles off the coast of Madalena do Mar so we set the course to catch up with the group. We soon had a sighting involving Striped dolphins (Stenella coeruleolba), a species we have encountered quite often this week, indicating that larger schools may be currently foraging around the archipelago.

At a distance this oceanic dolphin can be mistaken for its close relative, the Atlantic spotted dolphin (Stenella frontalis), but close up it becomes evident that they are in fact very different. Both animals belong to the genus Stenella, a delphinid taxonomic group that currently includes five species. The name Stenella originates from the Greek word Steno, meaning narrow and the majority of its members inhabit the tropical and subtropical areas of our oceans. While the Atlantic spotted dolphin is solely seen in the Atlantic Ocean, the Striped dolphins can also be encountered in the Mediterranean Sea and the Pacific Ocean with their diets varying according to their location.

Although the Striped dolphin is one of the oceanic dolphins that is most notorious for forming large pods containing hundreds of individuals in the open ocean, the group formations close to shore look very similar to those of Atlantic spotted dolphins. However, as we approach such groups we immediately notice some unmistakeable differences in their behavior. Spotted dolphins almost always approach our boats out of curiosity and are, generally speaking, a very interactive species. During sightings with Striped dolphins, on the other hand, such approaches are quite rare as they often display quite evasive behavior and keep well away. Up close the physical features that distinguish the two species are also quickly visible. Striped dolphins are the same size as spotted dolphins but are a little chunkier and have a long black stripe extending from their eye along their blue/grey flank.

Despite their shy character, these are truly beautiful dolphins that display a unique synchronised group behavior during a sighting. These dolphins were seen on all tours today and the guests on our zodiac also enjoyed sightings with Bottlenose dolphins (Tursiops truncatus) and Atlantic spotted dolphins. The characteristic behavior of different cetacean species also means that certain animals have gained their own little fan club amongst the Lobosonda team and our guests. While a few members of our team particularly love the energetic character of the Striped dolphin, the Atlantic spotted dolphins won the heart of a little special guest today on board our zodiac with my colleague Fatima. She asked me to forward the following message:

To my new, little friend and Dolphin-magnet Konstantin; what I enjoyed most besides a sighting with our favorite dolphins, the Atlantic spotted dolphins, was your happiness. Thank you so much for that, was great to have you with us! Fatima

Well, our zodiac isn’t named Stenella for nothing! The dolphins of this genus continue to capture our hearts and make us smile.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Striped dolphins

Stenella

12:00 Atlantic spotted dolphins, Bottlenose dolphins, Striped dolphins

18:00 Atlantic spotted dolphins, Bottlenose dolphins, Striped dolphins