02.10.2018 – Social skills

Both our boats enjoyed sightings involving Bottlenose dolphins (Tursiops truncatus) in the morning and an encounter with a large Baleen whale (Mysteceti) with her young calf in the afternoon. It was difficult to determine the species of the whales due to the fact that the animals engaged in a number of shallow dives and generally displayed a somewhat evasive behaviour.

As our zodiac was on its way back to the marina, we were extremely lucky to encounter a group of False orcas (Pseudorca crassidens) that were travelling close to the coast. It was highly likely that this was the same herd we had seen the previous day in the morning, only this time the animals were swiftly swimming towards the east. Once again the gregarious nature of these large deep-diving delphinids wasn’t short of impressive. The large animals spent a decent amount of timing leaping alongside the Stenella and riding the waves of our bow.

False killers are actually quite notorious for their charisma and somewhat altruistic nature. They have been known to interact non-aggressively with several large dolphin species that also frequent the waters of the island including the Bottlenose dolphin, the Rough-toothed dolphin (Steno bredanensis), the Short-finned pilot whale (Globicephala macrorhynchus), the Melon-headed whale (Peponocephala electra), the Pygmy killer whale (Feresa attenuata) and the Risso’s dolphin (Grampus griseus). Madeira’s location and the fact that it’s a relatively isolated marine habitat occurring close to the migration routes of many transient cetacean species, also makes encounters with mixed groups of cetacean species possible during our tours.

False orcas not only socialize with other species, they also often form close bonds with them. They have been observed responding to distress calls, protecting other species from predators as well as aid them in chilbirth by removing the afterbirth. Mating behavior with Bottlenose dolphins and Pilot whales has also been reported and such sexual interactions with Bottlenose dolphins have even lead to the existence of a Bottlenose-False-orca hybrid known as the Wolphin. Two of these impressive looking hybrids are currently held in captivity  but their existence has also been documented in the wild.

Despite their altruistic nature to most other cetaceans, False orcas have also been observed pursuing and killing smaller dolphins. This might explain the temporary absence of our summer dolphins, the Atlantic spotted dolphins (Stenella frontalis) and the closely related Striped dolphins (Stenella coeruleoalba). We eagerly anticipate their return but, in the meantime, are thrilled to enjoy the company of the magnificent and mysterious False killer whales.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Bottlenose dolphins

14:30 Baleen whales

Stenella

10:00 Bottlenose dolphins

15:00 Baleen whales, False orcas