06.09.2025 – Windy days and rare sights
September 15, 2025
Today we had a different sighting during the day. I speak about the Smooth hammerhead shark (Sphyrna zygaena). We were on our way back from the second trip, during which we saw some Blainville’s beaked whales (Mesolpodon densirostris), when we encountered this prehistoric being.
It is the second largest hammerhead species as it can grow up to 5m in length. The interesting shape of the head is an adaptation for hunting. All sharks have some electroreceptors, the Ampullae of Lorenzini, at the tip of the head which they use to sense the electric field of prey, even if that prey is buried in the sand. The increased head allows the hammerhead sharks to have more of these receptors and thus making them experts in hunting buried animals like rays, one of the main prey of hammerhead sharks.
Apart of the shark and the beaked whale, we also encountered some other cetaceans. We saw some Bottlenose dolphins (Tursiops truncatus) and Sperm whales (Physter macrocephalus).
By Horst Schulte
Sightings of the day
Ribeira Brava
09:00 Bottlenose dolphins
13:00 Blainville’s beaked whale, Smooth hammerhead
Stenella
09:30 Bottlenose dolphins, Sperm whales
13:30 Blainville’s beaked whales
16:30 Bottlenose dolphins
