Researchers in a new study have found that dolphins coordinate their behavior to work together on shared tasks. More specifically, the ‘initiator’ will wait on their partner and the ‘follower’ will then coordinate their actions to match the initiator’s behavior.
Cooperation is one of the most important abilities for any social species. From hunting, breeding, and child rearing, it has allowed many animals — including humans — to survive and thrive. As we better understand the details on how animals work together, researchers have been focusing on the degree of cooperation and the cognitive abilities required for such activity.
Dolphins are well known to operate in social groups — a group of dolphins is a pod — in a ‘fission-fusion society’, where groups merge and split over time. Previous studies have even suggested that dolphins may understand a partner’s role in cooperative tasks. However, due to the complex mechanics of conventional experiments it has been difficult to determine how this behavior was characterized in dolphins.
The researchers tested dolphin cooperation using the Hirata task, a cooperative pulling paradigm that has been used to demonstrate that a significant number of animals — including chimpanzees, dogs, and elephants — have cooperative abilities.
“In our investigation, we wanted to find out how bottlenose dolphins coordinate their cooperative behavior. Our setup was the Hirata’s rope-pulling task: where two dolphins pull on opposite ends of a rope simultaneously to receive rewards.”
-Dr. Chisato Yamamoto, researcher
The study results demonstrated that dolphins are just as cooperative as other animals. In their test, the researchers first sent out the initiators in the direction of the task, then and after a few seconds a follower was sent. They observed that the initiator waited for their partner to reach the task, and the follower would coordinate their swimming speed to match the initiator’s behavior.
“Having initiators and followers coordinate behavior for a task has previously been observed in chimpanzees and orangutans. But dolphins appear to be more flexible in their coordination, capable of changing their actions depending on where their partner is.”
Team leader Masaki Tomonaga explains that this coordination is likely rooted in dolphins’ patterns of affiliative behavior, a method of social interactions that functions to reinforce social bonds with a group.
Journal Reference: Chisato Yamamoto, Nobuyuki Kashiwagi, Mika Otsuka, Mai Sakai, Masaki Tomonaga. Cooperation in bottlenose dolphins: bidirectional coordination in a rope-pulling task. PeerJ, 2019; 7: e7826 DOI: 10.7717/peerj.7826