I received this from Caroline Blackmore at Southern Cross in regard to the
‘Killer Babblers’. It may have already been posted and if so I apologise.
Babblers often form same-sex coalitions to disperse (males more often than
females) and in my thesis I speculate that a coalition will kill the incumbent
same-sex line to take over a territory; and, if the coalition partner are close
in age, will kill each other off once they’ve successfully acquired the
territory. Although I never witnessed it there was indirect evidence e.g. in a
group of three, a dominant male and his younger helper brother would frequently
be replaced by a new dominant male and his younger brother. I couldn’t rule out
divorce as I didn’t see what happened, but it did seem unlikely that both males
would spontaneously die at the same time, to be replaced almost immediately by
a new coalition. Also they could have just been driven off but I never sighted
them again over a large area. I also had a very telling incident where two
unrelated females of about the same age established a new territory on a
reveged site. They held it for ca. a year, then within a week of a male joining
them one of the females was found dead. In another cooperative breeder, the
Arabian babbler, female coalitions will kill to take over a territory, and male
coalitions initially share paternity but eventually kill each other off until
there is only one.
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