04.07.2022 – 5 socialites

Cetaceans may come in different shapes, sizes and have various prey preferences but they all share is the ability to lead complex social lives… and social animals need a valid reason to hang out together.

The structure of a dolphin pod is anything but a coincidence. Research has emphasised the selective nature of dolphins when it comes to choosing the conspecifics they spend more time with and studies have highlighted the importance of alliances, companionship and associations across all species.

Atlantic spotted dolphins (Stenella frontalis) are thought to form groups according to their life phase, which is obviously closely related to the age of the animals. This is especially true for males and such groupings according to age can easily be identified thanks to the characteristic spot pattern of the species that intensifies as the animals age. The curious nature of the spotted dolphins also helps and everyone on board this mornings tour could easily see that the grey- coloured dolphins darting towards our speed boat were juvenile animals. Our spotter soon sent us to calmer waters further east to a group of Risso’s dolphins (Grampus griseus), another species of dolphin that carefully selects its peers. In the Azores, the species is said to form small clusters of 3-5 animals within their pods, that consist of animals that nurture long-term relationships. The pod even contained a few small calves and I couldn’t help but wonder whether any of these young animals will remain friends in the future.

In the afternoon our team had the chance to meet some more social cetaceans. Bottlenose dolphins (Tursiops truncatus), another species which is renowned for long-term friendships and associations among conspecifics, were met during the afternoon tour along with a pod of Sperm whales (Physeter macrocephalus). While dolphins rely more on friendships, female sperm whales maintain strong bonds with the members of their birth pod with whom they often remain their entire lives. Male Sperm whales leave their birth pods to eventually lead a nomadic life and voyage through the oceans alone very much like many baleen whale species. Our team also managed a sighting with a Bryde’s whale (Balaenoptera edeni) in the evening, a curious and elegant species that often interacts with other baleen whales here in Madeira.

Knowing how intelligent these creatures are and how complex their lives can be only makes sightings on eventful days like these so much more humbling!

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Risso’s dolphins

Stenella

10:00 Atlantic spotted dolphins, Risso’s dolphins

14:00 Atlantic spotted dolphins, Bottlenose dolphins, Sperm whales

17:00 Atlantic spotted dolphins, Sperm whales