22.08.2021 – Big menu

Many species of cetaceans feed on a variety of prey, from schooling fish at the surface, up to deep-sea fish and deep-sea squid. We frequently see the large groups of Atlantic spotted dolphins (Stenella frontalis) hunting here during the summer and have watched them in pursuit of Atlantic mackerel (Scombrus scomber), Snipefish (Macroramphosus scolopax)n and have a hunch that they also must be feeding on squid. Spotted dolphins are in fact documented to include squid in their diet and the preference for the prey is apparently largest in pregnant females. It’s definitely reassuring to know that these small cetaceans have a lot of prey to choose from!

Our Stenella was also able to find a large Sei Whale (Balaenoptera borealis) swimming west a few miles off the coastline. The common name of these large rorquals is derived from sei, the Norwegian word for pollock, a sort of codfish. Sei whales would turn up together with the pollock along the Norwegian coast and both would feed on the abundant plankton. The whale wasn’t feeding when we encountered it but we got close enough to catch a glimpse of its Cookie-cutter shark bites (Isistius brasiliensis), a small deep-sea beast that gnaws at the bodies of cetaceans when they venture into deep waters.

During the last trip aboard the Stenella, a group of Bottlenose dolphins (Tursiops truncatus) were hunting at the surface around 8 miles off the coastline. It was an astounding sighting, especially since the species usually dives to hunt here in Madeira and rarely pursues prey at the surface. It was an incredible day with lovely encounters that made us all contemplate the variety prey for these cetaceans that must be swimming or drifting through the waters around the island.

By Paula Thake

Sightings of the day

Ribeira Brava

09:00 Atlantic spotted dolphins

17:00 No sighting

Stenella

09:30 Atlantic spotted dolphins (Snorkeling)

13:30 Atlantic spotted dolphins, Sei whale

16:00 Bottlenose dolphins