18.12.2020 – Friend or foe

The waters around the Madeira archipelago are visited by a surprisingly long list of cetaceans, with scientific institutions already confirming up to 29 different species! With such a cosmopolitan line-up of large marine predators and other ocean dwellers it definitely pays off to be street-wise and differentiate between friend and foe.

Cetaceans, particularly toothed whales, generally have no predators to fear since they’re pretty much at the top of the food chain but they may pose a danger to each other. Some larger toothed whales may bully, injure or even hunt smaller species so it’s definitely beneficial to understand who or what you’re dealing with.

Bottlenose dolphins (Tursiops truncatus) are especially smart when it comes to this. We’ve seen these intelligent dolphins with almost every single other cetacean species and the nature of these interactions may vary from peaceful to aggressive. We’ve watched them bully younger dolphins, marine turtles and even Sperm whales (Physeter macrocephalus), who seem like enormous wine barrels in comparison to the agile bottlenose dolphins.

They do, however, almost always behave in the presence of larger dolphins and are  encountered frequently close to Short-finned pilot whales (Globicephala macrorhynchus). Pilot whales generally seem quite passive during such encounters and, even today, didn’t mind the small group of Bottlenose dolphins intercepting their journey towards the Western waters of the island. Clearly, both groups were aware that neither posed a danger to the other and we watched them peacefully continue their journey as we began to head back to the marina. What an enjoyable morning!

By Paula Thake

Sightings of the day

Stenella

10:00 Bottlenose dolphins, Short-finned pilot whales

18.12.20