12.05.2022 – Little helpers

Finding cetaceans at sea is a challenging feat but it would be so much harder if it weren’t for our little helpers; marine birds. Keeping a lookout for marine birds is almost a rule of law when it comes to finding predators at sea since these opportunistic feeders gravitate towards predators pursuing prey to gain hunting advantages. and dolphins are particularly convenient in this area. The smart cetaceans do all the “dirty work”; they pursue schooling fish through coordinated group efforts and exhaust them before gathering them at the surface, where they are an easy catch for aerial predators. No marine bird in Madeira knows this better than the Cory’s shearwater (Calonectris borealis).

Like most other Tubenoses, a family of birds that includes all shearwater, petrel and albatross species, Cory’s have a strong relationship to their birthplace and return regularly to breed after their long voyages over the seas. The local colony of Cory’s returns every year to the archipelago to breed during the summer months. This means that they have an incredible knowledge on the area, which in turn grants them a unique advantage over other marine birds seeking prey at sea. These birds also famously target hunting situations involving dolphins or tuna making them our most reliable little helpers when tracking down cetaceans.

Today both our boats covered enormous search areas and followed our spotters guidance to areas flocking with Cory’s. The clients on board our Stenella even bore witness to two separate hunting situations involving Big-eye tuna (Thunnus obesus) which our crew investigated for possible associative feeding with dolphins. The only hunting situation marked by the Cory’s that actually involved dolphins was in Funchal which, sadly, was out of range for our traditional boat which returned to Calheta without a sighting. Our zodiac managed to reach the area and our guests were thrilled at a short but sweet encounter with Short-beaked common dolphins (Delphinus delphis) that were pursuing a shoal of mackerel two miles infant of Madeira’s capital.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 No sighting

Stenella

10:00 Short-beaked common dolphins