Dolphins have long been considered one of the most intelligent animals on the planet.
Breakthrough research by scientists at the University of Western Australia (UWA) has found that male bottlenose dolphins keep their individual vocal labels or "names", helping them to identify friends and rivals in their social group.
WA's Shark Bay dolphins can identify each other by unique calls similar to how humans use names. Source: Supplied: University of Western Australia
In many species, animals in a group will make their calls similar to each other when they share a bond.
This type of behaviour is also seen in parrots, bats, elephants and primates, and is a way of showing the strength of their relationships and their group to others around them.
But in the case of the male dolphins in Shark Bay, it’s a lot more individual according to Dr Stephanie King from the UWA Centre for Evolutionary Biology.
“Even when voice features are removed, it’s the structure of the signal that encodes the identity of the animal. And this is where it’s comparable to a human name," she said.
"Dolphins can use it to introduce themselves, but they could also copy the whistle of another animal in order to address that individual.”
UWA researcher, Dr. Stephanie King, says while the behaviour may be unusual "it allows dolphins to negotiate a complex social network" of alliances. Source: SBS
It's the latest discovery in an ongoing study of the area's dolphins which began 35 years ago.
And while the behaviour has been described as both fascinating and unusual, the research team say it plays a big part in how the dolphins work together as a group.
“Retaining individual names is more important than sharing calls as it allows dolphins to negotiate a complex social network of cooperative relationships," Dr King said.
"This formation of alliances within alliances is very unique and it’s the only example we have in the animal kingdom outside of humans.”
Male Dolphins typically form small groups of two or three to guard a female from other groups who may try to steal her away.
These groups form parts of larger alliances of 10 to 14 males.
A large group of dolphins working together in Shark Bay as researchers record their sounds with underwater microphones. Source: University of Western Australia
The study also discovered that male dolphins use physical contact to strengthen their bonds instead of the having a similar group call, something similar to how humans touch and hug each other.
“This included petting, stroking and performing synchronous behaviours as an alternative means of advertising their strong social bonds,” Dr King said.
The relationship between the male dolphins has been compared to the relationship between a mother and her calf, helping to build a relationship which can last a lifetime.
While this research was looking specifically at male dolphins interacted in groups, Dr King says that all dolphins regardless of gender have their own individual vocal labels.
The study will next look at the males’ relationships with each another more closely, in the hope to see whether some alliances are given more importance than others.
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