29.09.2019 – Routine vs ritual

While some animals have some sort of daily routine, for instance feeding at certain times of the day, dolphins tend to be more opportunistic in their daily activities. We do often observe hunting behaviour in the morning or at dusk but, if the opportunity presents itself, dolphins will also gather to to hunt and feed in the afternoon hours. While routine is not really a thing with dolphins, ritualistic behaviour is.

Ironically, such ritualistic behaviour has been observed with a rarely encountered specie of deep-diving dolphin; the Rough-toothed dolphins (Steno bredanensis). These prehistoric looking cetaceans are readily distinguished from other dolphin species out at sea due to their uniquely-shaped, conical head that slopes into a long beak with white lips. Notoriously intelligent and moving in small, tightly knit groups of 15-20 animals, these deep-diving cetaceans roam the deep waters of tropical latitudes. While little is known about the social behaviour of these dolphins, the bond within pods are thought to be relatively strong which can be deduced from the constant body contact amongst the animals as they’re swimming and from some observed “rituals” amongst pod members. During such rituals, the dolphins present dead fish to one another and pass it around without eating it. It is unclear what implications such behaviour may have but it is only one type of ritualistic behaviour amongst many others seen with dolphins.

Post-mortem rituals have also been observed amongst different dolphin species, where adults hold onto their yoUng for a substantial amount of time after its passing, a behaviour that seems consistent with grieving. Local biologists observed this grieving amongst Atlantic spotted dolphins (Stenella frontalis) in 2015, another species we encountered today. They classify it as nurturant behaviour, a term describing a wide variety of social activities associated with dolphins including, social grooming, exchanging gifts and even adoption. 

Well, one can expect such complex behaviour with unclear implications from social animals like dolphins but one question is still pending; how objectively can we interpret the behaviour of these animals without associating their behaviour too strongly with our own? One things for sure; you cannot help but feel connected to these animals and I’m positive the guests aboard our tours today felt the same.

By Paula Thake

Sightings of the day

Ribeira Brava

13:30 Rough-toothed dolphins

Stenella

09:00 Atlantic spotted dolphins

15:30 Atlantic spotted dolphins, Rough-toothed dolphins