Off in one of the few remaining relatively primeval natural environments of the world — the Bili Forest of the far-northern portion of the Democratic Republic of the Congo — lives a band of very large chimpanzees that possess a number of very strange qualities and behaviors.

The local folk-stories of the surrounding region make note of massive ape-like creatures that kill and hunt lions, catch fish, and — the stories go — howl at the moon. With many local hunters mentioning an animal that looks something like a cross between a chimpanzee and a gorilla — an animal that apparently, according to the stories, is unaffected by poison darts, as the other apes are.

While you may be now making the assumption that such stories can’t possibly be true, you’d actually be wrong — a fair amount of research has gone into this subspecies of chimpanzee over the last few decades, and there is apparently quite a lot of truth to the stories.





One of the first researchers to get a close up view of the Bili Apes — pretty soon after a 5-year-long civil war ended in 2003 — was a speciality in primate behavior by the name of Shelly Williams. Williams described the experience thusly:

“We could hear them in the trees, about 10 meters away, and four suddenly came rushing through the brush towards me. If this had been a mock charge they would have been screaming to intimidate us. These guys were quiet, and they were huge. They were coming in for the kill – but as soon as they saw my face they stopped and disappeared.”

Sometime after that, in 2004, a man by the name of Cleve Hicks from the University of Amsterdam spent ~18 months in the region field-watching the Bili apes.

One of the most interesting things he saw in that period of time, followed on the tracking of loud calls coming from what sounded to be the same spot for a number of days. After investigation, it was clear what the calls were related to — he came dead-across a large male chimpanzee feasting gorily on a dead leopard.

According to Hicks, he can’t be completely sure that the animal was killed by the chimpanzee — but the event certainly does give a lot of credence to the folk-stories that mention them hunting and eating lions, doesn’t it?

Given the fact that during the very limited time that the researchers were able to observe that population (and usually only from a great distance) there was strong evidence that they killed a leopard, certainly does make you think. Maybe they do eat lions?

While it may not be something that many people in the modern world are aware of, chimpanzees are freakishly strong — much, much stronger than a human of the same size. While “strength” is something that can mean a lot of different things, I suppose, there is no doubt that chimpanzees possess a degree of physicality that is simply lacking in modern humans — as a notable primate biologist put it, they are very “explosive sprinters, climbers, and fighters”.

(As an anecdote, I recall hearing from someone that works with chimps a story about a large male putting deep dents into a very, very thick steel door (they have very dense bones).)

Anyways.. back to the Bili Apes.

At a later point in the research Hicks had a lucky-break when one of the trackers he was working with suggested a place for them to visit.

“We were told of this sort of fabled land out west by one of our trackers who goes out there to fish,” Hicks stated. “I call it the magic forest. It is a very special place.”

It was there that the researchers came across a large community of the apes that showed the same interest and “naivety” with regard to humans that some earlier reports had mentioned. The apes of this community (including the old males) would apparently “surround their human visitors and show curiosity towards them, but would not attack or become threatening.”

“What we have found is this completely new chimpanzee culture,” Hicks noted, when discussing the event in an interview back around the time that the work was done.

Of particular note with this community was the fact that they seemed to generally nest on the ground (very uncommon for chimps, but not for gorillas).

Colin Groves, a primate morphology researcher at the Australian National University in Canberra, noted: “The ground nests were very big and there was obviously something very unusual going on there. They are not unknown elsewhere but very unusual.”

“How can they get away with sleeping on the ground when there are lions, leopards, (and) golden cats around, as well as other dangerous animals like elephants and buffalo?” Hicks commented.

“I don’t like to paint them as being more aggressive, but maybe they prey on some of these predators and the predators kind of leave them alone.”

Also, interestingly, the community has what Hicks referred to as “smashing culture” — having found hundreds of large-snails and hard-shelled fruits that had been smashed open to get to the meat and fruit. Also, somewhat humorously, Hicks had seen some of the chimpanzees carrying whole termite-mounds to rocks where they could then be smashed/broken open. The remains of a large turtle that had, apparently, been smashed open by the chimps was also found by the researchers.

Another interesting behavior that was observed was the use of sticks for ant “fishing”, which is a relatively common technique for “normal” chimps — but, in this case, the tools used were up to 2.5 meters long. Much longer/bigger than the tools usually seen used.

Out of everything though, the curiosity and naivety about humans is perhaps one of the most interesting qualities of the Bili Apes.

Here’s a quote on that matter:

“Gorilla males will always charge when they encounter a hunter, but there were no stories like that” about the Bili apes, according to Ammann. Instead, they would come face-to-face with their human cousins, stare intently in half-recognition, then slide away quietly. Hicks’s group later confirmed and somewhat expanded those observations, saying that when they encountered a large group of Bili apes in the deep forests (far from the roads and villages), they not only approached the humans, but also would actually surround them with intent curiosity.

As you can probably guess, while that would certainly made for a fascinating experience, it also puts the Bilis at great danger to bush-meat hunters and poachers — which have until very recently not operated in the very remote region where the Bili Apes live.

“Things are not promising,” stated Karl Ammann, the wildlife photographer who’s been credited with sparking interest in the apes back in 1996. “The absence of a strong central government has resulted in most of the region becoming more independent and lawless. In conservation terms this is a disaster.”

Hicks has said much the same thing, noting that while the chimpanzees are an endangered species and fully protected in DRC law, “it is only a law on paper”.

Interestingly, Hicks has identified both the official security forces and various militia forces as the cause of much trouble, and corruption as well. Putting that thought quite bluntly when he stated: “I think the military are giving guns to the poachers.”

As of June 2007 illegal poachers have begun operating in the Bili Forest in notable numbers. Here are some figures worth reading related to that:

Over a 14-month period between September 2007 and November 2008, researcher Cleve Hicks and his Congolese assistants documented 34 chimpanzee orphans and 31 carcasses for sale in the nearby Buta – Aketi – Bambesa region (seven of the orphans have been confiscated and adopted).

Laura Darby and Adam Singh have seen another nine chimpanzee orphans and three carcasses in Aketi, Buta, and Bondo, since Hicks left in November. In addition, Hicks observed a large quantity of okapi and leopard skins along with elephant meat and ivory. It is likely that this exploding bushmeat trade is now making its way into the Bili region with the gold miners.

As with more or less all of the remaining megafauna animals of the world, the future existence of the Bili Apes is a very open question — this is almost entirely due to seemingly ever-expanding human settlements and industry/commercial-activity.

This baby/young chimpanzee in the image below isn’t a Bili — it’s a different subspecies — but I feel that it’s worth posting here. It really sums the whole thing up doesn’t it?

(Author’s note: Mr Hicks replied in the comments below and corrected me, the chimpanzee in the image is the same subspecies, and probably part of the same population as well. It was actually offered for sale to Mr Hicks by a government employee, apparently.)

On a lighter note, below are some videos (taken by camera-traps) showing the Bili Apes in their home range, coming to us via the Lukuru Foundation:

Mother & Adolescents (older adolescent in background)

Second Adolescent’s Tool-Use (after making tool in background of first video)

Old Males

Young-One Curious/Bemused(?) About/By Camera

Band of Males Patrolling

Image Credits: Bili; Dr Cleve Hicks; Screen Capture