(MENAFN - The Conversation) In life it often pays to keep a close eye on competitors and rivals. Historian Doris Kearns Goodwin's book, Team of Rivals , tells how US president Abraham Lincoln persuaded each of his political rivals to join his cabinet, thereby turning them into his allies.
But the formation of alliances with potential competitors is not unique to humans. In a study published in Current Biology , my colleagues and I describe how such behaviour is also found among bottlenose dolphins.
We found that individual male dolphins retain their unique signature whistle, allowing them to recognise many different friends and rivals in their social network, something not currently known from any other non-human animal.
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The Shark Bay network
In Shark Bay, Western Australia, pairs and trios of unrelated male dolphins work together in alliances to herd single females for mating opportunities. On a second level, teams of alliances work together to steal females from opposing alliances and to defend against such theft attempts.
The males are therefore cooperating with individuals with whom they are in direct reproductive competition, since paternity success cannot be shared. But the bonds between these teams of rivals are as strong as those between mothers and calves, and these friendships and alliances can last entire lifetimes.
So how do these males keep track of all these different relationships, and how do they maintain such strong social bonds? The answer may lie closer to home than you think.
Vocal labels for dolphins
Previous research has shown that bottlenose dolphins develop an individual vocal label known as their signature whistle, which they use to broadcast their identity.