Our Stenella set out with a clear course this morning. Our spotter had located some Bottlenose dolphins (Tursiops truncatus) near one of their favourite hangouts in the Southwest, the waters outside Madalena do. Mar. The groups was mainly composed of females and juveniles, with the adults keeping a wary distance whilst the younger animals curiously approached our bow. Before long, however, a large adult dolphin appeared close tour boat and its distinctly marked dorsal fin and characteristic bubble trail at the surface soon allowed us to recognise it as an individual we had encountered a couple of times before.
For now, our assumption is that this animal may in fact be a large female since we often see it accompanying nursery groups where calves are present. The animal is definitely an older dolphin, boasting scratches and scars reminiscent of its many encounters with other creatures, including the scars on its beak that prompted me to name it Pacino, from the main actor Al Pacino in Scarface. Of course this is not a suitable name for a female dolphin but, in my defence, it is very hard to differentiate between male and female dolphins at sea. One can assume the gender of an individual by assessing the group composition but the only way to be sure is to check the ventral side for mammary slits near the genitals, which would mean that the animal is female.
We moved on from Pacino and his\her posse to a dispersed group of Short-beaked common dolphins (Delphinus delphis) who kept their distance for some time before carefully approaching our zodiac, giving us a good glimpse of their decorative flanks. These dolphins only remain in these waters during the colder months of the year with a few small groups with calves also staying for the summer. Another winter visitor is the beautiful Northern gannet (Morus bassanus) who, like the common dolphin, comes to feed on the abundant schools of mackerel in these waters before heading further North for the summer.
By Paula Thake
Sightings of the day
10:00 Bottlenose dolphins, Short-beaked common dolphins, Northern gannets