Why Do Dolphins and Whales Interact Frequently? Researchers May Have Found the Answer

Whales and dolphins have an interesting relationship. Some whales are known to hunt dolphins, but certain observations indicate that they also share social relationships. The social aspect of this dynamic has been documented in the journal Discover Animals. For the study, the researchers examined several videos featuring interactions between multiple dolphins and whales. Experts mainly focused on the way whales reacted and responded to dolphins in the videos. The reason behind this was that dolphins are typically believed to harass whales by their actions, according to experts. The team wanted to understand how much of the interaction was friendly and how much was acrimonious. 

Playtime between Whales and Dolphins

Though researchers have often observed whales and dolphins playing with each other in the marine ecosystem, the reasoning behind the interaction has eluded them. The objective of the study was to understand if the social dynamic between these two marine beings was one-sided or mutual, according to Popular Science. To understand the answer, the team observed 425 baleen whales, belonging to around six distinct species.

The species included Humpback whales (Megaptera novaeangliae), gray whales (Eschrichtius robustus), and fin whales (Balaenoptera physalus). For dolphins, they considered around 1,570 creatures, which included bottlenose dolphins (Tursiops), common dolphins (Delphinus delphis), and Pacific white-sided dolphins (Lagenorhynchus obliquidens). The observations implied that in most instances, their "playtime" with each other was a mutual activity. 

Instances of Interaction

The videos used in the study came from social media platforms, like Facebook, YouTube, and Instagram, as well as footage from citizens across the world, according to The Conversation. In total, there were 199 interactions from around 17 countries in these videos. They considered two other interactions from footage gathered by camera tags attached to humpback whales. These two videos offered a "whale's-eye view" of these encounters. In these camera tag videos, dolphins were following whales not only at the surface but down to the ocean floor. The dolphins maintained eye contact and also touched the whale's head, indicating that they were initiating positive social interaction, not harassing them.

Behaviors, such as rolling, tail slaps, bow riding, and rubbing, were observed and categorized, along with the classification of dolphin positions with respect to whale body parts, like head, tail fluke, and flank, during the interactions. 80% of all the noted interactions were dolphins swimming close to the whale's head, behavior that can be labeled as bow riding. Amongst whales, humpback whales were the most involved, while in dolphins, bottlenose dolphins led the pack. These observations challenged previous views that such interactions were rare and not widespread. 

What Happened in these Interactions?

The videos showcased that the interactions were mostly initiated by dolphins through practices like swimming in formation, bowriding, or simply touching the whales. In more than one-quarter of the cases, whales reacted in a 'friendly' manner. The humpback whales were observed to gently turn towards the dolphins, roll, or expose their bellies, while responding to the initiation. Signs of aggression, like tail slaps, were detected in only 5% of the cases. Hence, researchers determined that more than one-third of the noted interactions were positive or signs of mutual play time.

The findings shed light on the social capability of marine mammals in their ecosystem. The interaction between dolphins and whales reveals that interspecies interaction in the marine ecosystem may be more prevalent and complex than previously believed. Here, both dolphins and whales are contributing to the interaction, which reflects advancement in their cognitive and emotional capabilities. The fact that they can engage with a being so different from their own indicates that they are not just capable of coexisting but also of creating a community.