19.01.2019 – Compatible companions
We saw two different species of dolphin during our trip this morning on the Stenella, that share many of the traits common amongst most oceanic dolphins but also differ decisively in their behaviour, social lives and appearance. First, we encountered the Short-beaked common dolphins (Delphinus delphis), a small colourful species that is abundant around Madeira during the winter months and that can easily be appreciated up close because of their interactive nature. The commons instantly approached our boat as we arrived and rode the waves of our bow. It was a big group with several animals swimming alongside our zodiac while others were socialising and travelling east.
Such large aggregations can be expected with smaller dolphin species and are less frequent with larger Delphinids, such as Bottlenose dolphins (Tursiops truncatus). Generally Bottlenose dolphins occur throughout the year in Madeiras waters and tend to travel in smaller groups consisting of 15-25 individuals. Our encounter with Bottlenose dolphins today was also very different to the one we had with the commons, with the animals giving us very little attention and more preoccupied with their pursuit of a large school of fish. The large ball of terrified fish even swam towards our zodiac in an attempt to hide from their hunters and were perfectly visible beneath the clear, blue ocean surface.
Whether big or small, schools of dolphins are usually a collection of several small units known as sub-groups. Such sub-groups consist of like-minded individuals, that either happen to be in the same life-stage, gender or quite simply share the same interests. Such friendships amongst dolphins may stretch over a large span of time, often several years, but can also be quite short-lived with the animals gathering simply out of opportunity.
Its difficult to determine the nature and intensity of the companionships amongst the animals during a sighting but it is nonetheless breathtaking to observe these beguiling creatures interact amongst themselves. Our guests on board were also united in their fascination and interest for these charming inhabitants of the Atlantic Ocean.
By Paula Thake
Sightings of day
Bottlenose dolphins, Short-beaked common dolphins