Ankur Desai

But time is running out for anyone hoping to influence this election.

A record turnout is expected on Sunday.

Rarely has so much attention from around the world been focused on this small Central European country.

Nick Thorpe reporting.

Chimpanzees are known for their intelligence and curiosity, but also their potential for violence.

They regularly fight over food, mates and rank.

But new research has documented how that aggression seems to have bored over into what amounts to a civil war.

The study in the journal Science follows 30 years of chimp behaviour in Kibale National Park in Uganda.

It's given us an insight into how and why feuds develop between groups.

One of the co-authors of the study is John Mitani, a primate behavioural ecologist at the University of Michigan in the US.

He told my colleague Pete Ross that he initially went to study the group because it was unusually large.

There were well over 100 chimpanzees at the time.

It took several years, actually, to nail down the precise number of chimps, but it was clear that the number was well over 100, and that was double the size of any other chimpanzee group that had been studied in the wild previously.

In this very large group of chimpanzees, I think one thing that they had to do in order to maintain cohesiveness and

to hold together with so many chimps around is to actually cooperate with each other.

And we spent many years documenting the cooperative behavior of the male chimpanzees in this group.

And with that cooperation, they were able to dominate their neighbors, they expanded their territory as a result, they gained more food, and they gained fitness or reproductive benefits.

And the group increased even more in size.

So it sounds like things were going swimmingly and then there was a moment and then violence broke out.

Exactly.