It appears dolphins are identical to humans in the aspect of making friends. They form intimate friendships with other dolphins that share the same interest and connection. An international team of researchers from the Universities of Western Australia, Zurich, and Bristol has these findings and published it in the Proceedings of the Royal Society B. The team provides additional insight into the social behaviors of these extraordinary animals.
The natural base for an iconic population of Indo-Pacific bottlenose dolphins is a World Heritage area in Western Australia, which is known as Shark Bay. This place is where the researchers have been observing with the use of marine sponges as foraging tools. This learned method passed down from generation to generation, helps some dolphins, "spongers," find food in deeper water channels. While the tool-using technique is well-studied in female dolphins, the new research examined the male dolphins specifically.
The researchers analyzed a subset of 37 male dolphins that comprises of 13 spongers and 24 non-spongers with the use of behavioral genetic and photographic data collected from 124 over nine years, between 2007 to 2015, of male dolphins during the winter months in Shark Bay.
The team discovered that male spongers spend more time associating with other male spongers than they do non-spongers; these bonds are based on similar foraging technique and not related to other factors.
The senior research associate at Bristol's School of Biological Sciences and a co-author of the study, Dr. Simon Allen, said that foraging with a sponge is a time-consuming and mostly solitary activity so it was long thought incompatible with the needs of male dolphins in Shark Bay, to invest time in forming close alliances with other males. The study suggests that, like their female counterparts and indeed like humans, male dolphins form social bonds based on shared interests. The research provides new insight into homophilous behavior in the social network of tool-using dolphins.
The lead author of the study at the University of Zurich, Manuela Bizzozzero, said that male dolphins in Shark Bay exhibit a fascinating social system of nested alliance formation. These strong bonds between males can last for decades and are critical to each other's mating success. Researchers were quite excited to discover alliances of spongers, dolphins forming close friendships with others with similar traits.
