10.01.2020 – Food, glorious food

Cetaceans react differently to the presence of boats and their reaction burns down to a number of different factors. It depends on the species, on how the groups are constituted (if several calves are present for instance), the different personalities of the animals and what they are currently up to. The three different species of cetaceans we met on todays tour seemed rather indifferent to our presence and the main reason for this seemed to be food.

The dispersed pod of Short-finned pilot whales (Globicephala macrorhynchus) seemed to be heading west to find a nice spot to dive and hunt for some deep-sea squid. Here the group usually scatters over a large area, with each individual engaging in its own sprint dive into the dark ocean. Of course, such individual hunts are merely a theory; these highly cultural animals may also hunt in groups but the high dispersion of pods during such foraging events suggests otherwise. Naturally, food always comes first so the disinterest in our Stenella was to be expected. 

Scattered within the pilot whale hunting grounds were a small group of Bottlenose dolphins (Tursiops truncatus), a species that generally shows little interest in our boats if another marine mammal species happens to be nearby. Such interspecies associations aren’t rare and are predominantly based on feeding advantages or protection. In this case, the Bottlenose were probably following the pilots to forage in the depths for the nutritious deep-sea squid. 

The Bottlenose and the Pilots weren’t the only ones interested in grabbing a bite. A group of Short-beaked common dolphins (Delphinus delphis) was herding school of Half-beaks (Belone belone) below the surface close by. These agile and swift hunters give their observers clues as to what type of prey they’re hunting through their behaviour at the surface. When hunting half-beaks, the dolphins often leap out of the water propelling some of the terrified fish with them at the surface. Again, the Stenella left the sighting area with no approach by the animals and decided to search the area for another possible sighting.

Just as our crew decided to head back to land, a small pod of pilot whales surfaced in a compact formation. In contrast to all our other sightings during this tour, this group seemed inquisitive with one young animal even spy-hopping at the surface. What a wonderful and rewarding finish to this eventful and interesting tour. 

By Paula Thake

Sightings of the day

Stenella 

15:00 Bottlenose dolphins, Short-beaked common dolphins, Short-finned pilot whales