19.09.2024 – The Millers

Published by Sarah Kather on September 27, 2024

What would you think if I said – “We’ve seen the Millers today!” – Someone famous from the island? Someone who’s taking care of the island’s windmills? Just a regular family on board our boats? Who are those millers? I am actually referring to a dolphin species, better known as Risso’s dolphin (Grampus griseus). These dolphins are everything but regular. We do not often encounter them – maybe once a week, maybe less. But if we do, we often find them many miles off the coast, at a depth of 2000 to 3000 m. Today, it has been one of those lucky days. I don’t recall knowing any cetacean species with so many different, creative names, depending on the country and region. In English and French, the dolphin is named after Antione Risso, a french naturalist who first described the species. The latin name Grampus originates from the word for ‘fat/great’ and is still used in many languages (e.g. dutch, italian, portuguese), while griseus means ‘grey’ and refers to their colouration, still included in the species name in many countries (e.g. Spanish, Catalan, Russia, Poland, Turkia). Actually, Risso’s dolphins do have plenty of different colorations, depending on their age and gender. They are born light grey, and while the females generally darken with age, both genders will attain many scars on their bodys (one of my favorite names – Arrdelfin, means ‘scarred’ dolphin in Norwegian). Because of a lack of pigments, every scar on their skin stays white. And this is why the Risso’s dolphin is called Moleiro – ‘the Miller’, in the Azores, where they are commonly seen. With age, especially the males will get almost completely white. Often one can follow the dolphins easily underwater once they are closeby the surface, even if they don’t break the surface yet to breathe. The males get heavier scarred due to competition between males, but both sexes also obtain scars from their prefered food source, being squid. As many squid feeders, a large, round head helps to focus sound waves and find their prey in deep, dark regions of the ocean. Some countries refer to the characteristic – ‘Round-headed-dolphin’ (Germany), ‘cauldron’ (Spain), ‘head like a pot’ (Catalonia). However you want to call them, it is certainly a delight being able to observe these unusual, elegant dolphins in the wild!

By Sarah Kather

Sightings of the day

Ribeira Brava

09:30 Risso’s dolphins

13:30 Trip cancelled due to weather conditions

Stenella

09:30 Risso’s dolphins, Bottlenose dolphins, Sperm whales

14:00 Sperm whales