New research suggests dolphins form their own "social networks" of friends.
A team of researchers at Harbor Branch Oceanographic Institute (HBOI) took detailed photo-ID surveys of the Indian River Lagoon (IRL) over a period of six-and-a-half years, allowing them to gain insight into the local dolphins' association patterns, habitat preferences, and movement behaviors, Florida Atlantic University reported.
The dolphins appeared to show both preference and avoidance behavior, and had some "friends" they liked and other individuals they avoided. They team also observed that the dolphins tended to form "communities" that occupied "discrete core areas" across the lagoon system's north-south axis.
"One of the more unique aspects of our study was the discovery that the physical dimensions of the habitat, the long, narrow lagoon system itself, influenced the spatial and temporal dynamics of dolphin association patterns," said Elizabeth Murdoch Titcomb, research biologist at HBOI who worked on the study with Greg O'Corry-Crowe, associate research professor at HBOI; Marilyn Mazzoil, senior research associate at HBOI, and Elizabeth Hartel. "For example, communities that occupy the narrowest stretches of the Indian River Lagoon have the most compact social networks, similar to humans who live in small towns and have fewer people with whom to interact."
The new study provides insight into how dolphin communities organize themselves and interact. It also helps scientists understand how dolphin populations use their environment and how these behavours lead to breeding patterns and the spread of disease.
Scientists have been using photo identification to conduct dolphin studies in the IRL since 1996, which has led to the identification of 1,700 individual dolphins. The IRL dolphins are now on their third generation of individuals looked at in the recent study.
The findings were published in a recent edition of the journal Science.
