Chimpanzee feud turns toxic in Tanzania

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You think you have a dysfunctional clan?

Check out the family feud involving Humphrey, Charlie and Hugh.

In the early '70s, the trio was part of a tight-knit community of wild chimpanzees in Gombe National Park, Tanzania. 

These are some of the same chimps that British primatologist Jane Goodall was studying at the time, looking at social and family dynamics.

"Jane and other researchers who came to Gombe initially had this idea that chimpanzees were these idyllic forest-dwelling species that could provide this model for what humanity could be like," says Duke University researcher Joseph Feldblum. "They thought they were peaceful and egalitarian."

They were about to get a reality check of the wild kingdom variety.

According to a new study, the same things that fuel deadly clashes in humans — like power, ambition, and jealousy — can also tear apart chimpanzees. You'll recall from all those wildlife documentaries that chimps are our closest animal relatives.

In Gombe, Goodall and her colleagues watched a once-unified group of chimps disintegrate into two rival factions.

"There's still a bit of uncertainty, even with people who were there at the time, about exactly what happened," Feldblum tells CBC News.

But thanks to new digitized data taken from Goodall's own field notes from that period, Feldblum and a team of scientists were able to get a clearer, more detailed picture of what they call "the seeds of the conflict."

"We were able to examine the course of the split in more detail and pinpoint when it became obvious more precisely," says co-author and Duke anthropologist Anne Pusey.

'When Hugh and Charlie came charging … they were very intimidating'.- Prof. Anne Pusey, Jane Goodall Institute Research Center, Duke University

Pusey worked alongside Goodall in Gombe and has spent the last 25 years archiving and digitizing Goodall's handwritten notes.

Researchers have analyzed what they call "shifting alliances" among 19 male chimpanzees, leading up to the big split.

Clusters of males grew more distinct over time, they say. They started noticing that some males spent more time in the northern part of the park, while another group would hang out in the southern part.

Which brings us back to Humphrey, who was partial to hanging out in the north. Charlie and Hugh, who are believed to be brothers, withdrew to the south. There was increasing tension among this trio.  

"To be clear," says Feldblum, "Humphrey was the alpha male of the group at the time, and he was able to intimidate all the other males individually."

But the other two were no shrinking violets.

"When Hugh and Charlie came charging with their hair on end into a group, in tandem, they were very intimidating," says Pusey.

By 1971, researchers found the northerners and southerners met less frequently.

"The cliques began to harden," according to the new data.

When there were encounters, it got ugly.

"What chimpanzees do as part of dominance competition, male chimpanzees can puff up their hair and make themselves look bigger. They'll run and stomp and drag branches," says Feldblum.

'Very, very rare'

Researchers now believe this power struggle between the three "high-ranking males" triggered the big split.  

And perhaps, not coincidentally, this all happened at a time when female chimpanzees, especially the ones of child-bearing age, were in short supply.

"There were a lot of males competing for a small number of reproductively available females," says Feldman.

"What started as infighting among a few top males vying for status and mates is likely what eventually caused the whole group to splinter."

In anthropology and primatology circles, this is a big deal. This kind of split, which scientists call "fission," is rare.

"This makes our case very interesting," Pusey says in an e-mail.

"Chimpanzees have the unusual pattern of males staying in the community that they're born into," adds Feldblum. "And in male philopatric primates, these sorts of fissions are very, very rare."

"We showed that this was indeed probably the only split of one coherent chimpanzee group that's ever been observed in the wild."

It didn't end well for the simians of Gombe.

The split led to the brutal Gombe Chimpanzee War. Goodall called it the "Four-Year War" from 1974 to 1978, "a period of killings and land grabs, the only civil war ever observed in wild chimpanzees."

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