26.08.2018 – Free to choose

It wasn’t easy to find animals today but one species never fails to charm our guests during our tours. The Atlantic spotted dolphins (Stenella frontalis) are small, lively delphinids that frequent Madeiran waters in the summer months and tend to approach our boats more often than other cetaceans. Their sociable nature has attained them a unique reputation in the world of dolphins; the animals are so interactive, that we even have the pleasure of encountering them in the water during our snorkeling tours. Like all other dolphins, the spotted dolphins are undoubtedly superior to us in both their speed and their agility out at sea. So this leaves us wondering; do these intelligent animals make the purposeful choice to slow down and approach us in the water?

To be fair, choices do play a large role in the life of dolphins. As calves they follow the guidance of their mothers and remain at their side until a sibling is born and, from that point in their lives, dolphins become selective. They select their companions, choose when to mate irrespective of their reproductive cycle, adopt favorable hunting strategies and respond individually to attempts at interactions from other species. Dolphins are absolute opportunists but also become selective when it comes to their food and this is especially true for female dolphins who are pregnant or with a new-born calves. Pregnant dolphins tend to prefer squid, like the dead one we encountered during todays tour, and the animals don’t mind diving into the depths to hunt these animals. Lactating dolphins tend to stick to schooling fish due to the high fat content of the prey and the fact that they have a calf by their side and need to stay close to the surface. This of course cannot be generalised for all female dolphins, but such preferences have been widely observed.

Why the animals show altruism to human beings and choose to approach us remains an absolute mystery. In Laguna, Brazil, for instance, resident Bottlenose dolphins frequently aid fishermen in increasing their catch by indicating both the location and quantity of fish and drive the catch towards the nets. This ritualized behavior developed without the animals being trained or rewarded. In the Bahamas, spotted dolphins regularly frequent certain lagoons to encounter eager snorkelers and even participate in bioacoustic experiments with biologists. These are two simple examples amongst several stories where interactions with human beings present no advantages for the animals but these cetaceans decide to initiate them anyway. The collective term used for this behaviour is curiousity, which, considering the animals intelligence and selectivity, is a rather simplified explanation and doesn’t quite cut it.

Apart from our summer dolphins, guests aboard our Ribeira Brava this morning enjoyed a beautiful sighting with Blainville’s beaked whales (Mesoplodon densirostris) and an unidentified baleen whale mother with her calf. Occasionally, even these shy species decide to approach us. Whatever reasons these animals may have to come closer to us during our tours, the important is that we give the animals the time and space to make these choices.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Blainville’s beaked whales, Unidentified baleen whale

15:00 No sighting

Stenella

12:00 Atlantic spotted dolphins, Loggerhead turtle

15:00 Atlantic spotted dolphins