03.05.2019 – Spectres

During our trips today we encountered two species of dolphin who are both famous for their characteristic decorative markings: the Short-beaked common dolphins (Delphinus delphis) and the Striped dolphins (Stenella coeruleoalba). Both species generally show very different behaviour towards boats with the Commons being notoriously interactive while the Striped tend to display quite the opposite behaviour. Irrelevant of how close we manage to get to these beautiful dolphins during our careful approach out at sea, both species are easily recognisable through their characteristic pattern, which is also slightly different for each and every individual dolphin.

Recently, however, we have spotted many animals, particularly amongst the herds of common dolphins, that displayed some sort of pigmentation anomaly. The most frequently sighted animals in this category were individuals displaying a high degree of melanism, where an overproduction of the protective pigment resulted in the animal having a darker colour and losing the yellow tint in its characteristic hourglass pattern. Today, for the first time, I witnessed the opposite. Amongst the common dolphins this morning, one individuals color was so pale that we even managed to continuously locate it below the surface as the dolphins swiftly sped around our zodiac. The animal was almost ghost-like, a playful little spectre that was nonetheless perfectly integrated into the herd. Amongst the abundant Cory’s shearwaters (Calonectris borealis) at the site, we also saw a darkly coloured bird that bore a resemblance to the shearwaters but was somewhat darker. It may have been another species or an example of a bird experiencing a darker pigmentation on its feathers.

The patience of our lovely guests during the long search on our afternoon tour was rewarded with a sighting of Striped dolphins, that were swimming so swiftly that our traditional boat had trouble keeping up. Possible anomalies amongst this species are more difficult to document due to their evasive behaviour, which is completely understandable due to the frequent presence of young calves in the sighted pods. The sighting was brief and the dolphins kept their distance but our guests were nonetheless happy to have spent time on the ocean to witness these beautiful dolphins and their synchronised group dynamic.

By Paula Thake

Sightings of the day

Ribeira Brava

14:30 Striped dolphins

Stenella

10:00 Short-beaked common dolphins