01.10.2025 – Cephalopod collector

The huge misconception when it comes to the diet of dolphins is that they all eat fish and the importance of cephalopods, particularly deep sea squid, in their diet is often highly underestimated. Predators that enjoy a diet that includes a significant amount of squid are classified as teuthophagous, and Madeira is a perfect place for them to find their prey.

Our abundance of squid attracts cetaceans of all shapes and sizes and many of these cephalopod collectors were seen during todays trips. From the smaller Atlantic spotted dolphin (Stenella frontalis) that dives to hunt squid at night, to the suction-feeding Blainville’s beaked whales (Mesoplodon densirostris) up to the flexible Bottlenose dolphins (Tursiops truncatus) that will hunt cooperatively to feed on deep sea dwellers.

A species whose habitat association has been strongly linked to the presence of squid is the Risso’s dolphin (Grampus griseus). These beautiful dolphins rarely visit Madeira and their relationship to the island still remains to be determined, but studies from the Azores and other oceanic islands have shown that the species displays a clear preference for habitats with steep slopes or with other strong bathymetric features such as canyons or seamounts, also the perfect habitat for squid. In fact it has often been hypothesised that resident patterns are often strongly associated with squid distribution, so perhaps their presence during so many sightings this week could be related to that!

By Paula Thake

Sightings of the day

Ribeira Brava

09:00 Bottlenose dolphins, Risso’s dolphins

13:00 Atlantic spotted dolphins

Stenella

09:30 Bottlenose dolphins, Risso’s dolphins

13:30 Atlantic spotted dolphins, Risso’s dolphins

16:30 Blainville’s beaked whales