While
we flock to watch dolphins do tricks in large aquariums, we recognize that they
are intelligent mammals that are used to wandering freely around the oceans.
They travel long distances and don’t stake out small territories.
Connor
et al have been studying bottlenose
dolphins around Shark Bay for quite some time now and will have their latest report
in Proc. Roy. Soc. B and Gill has given us a pre-publication summary in BBC
Nature (1).
The
dolphin groups wander about the ocean in a well-organized society. Males form
alliances of different types to organize their females. At the ‘local’ level
two or three males get together to herd their females, but they form larger
gangs with up to a dozen or fourteen gang members to go raiding other dolphin
troupes to steal their females.
All
this is good fun if you are a young male dolphin, but of course they can
sometimes meet stiff opposition and then the dolphin gangs forget about looking
after what they’ve got. They band together into a little army to take on the
opposition.
Apparently
though, when they meet another group they don’t always want to fight, as would
be the case if it were territory that they were defending. As it’s their
females that they are worried about, if there is no obvious threat, they play
nice.
In
some cases, playing nice can mean groups joining up or having some small groups
of males going off with the new group. So it appears that they have a complex
social network with a variety of alliances. Only humans come close to
having such hierarchical alliances according to the authors of the study,
although the herding and stealing of females from other gangs makes me worry a
bit about the comparison.
