White-eyelid mangabeys

An encounter with the bird featuring the cover of my African bird book

A couple of weeks ago I went out to look for east bonobos on the west side. Considering the current ranging pattern, this was a reasonable gamble, although not successful that day. I chose a good spot, sat down on a log and listened for an hour or two. After a while I heard soft, pulsating vocalizations. I heard red-tailed guenons before, but this came from much closer and sounded more like a chicken. All of a sudden I saw a pair of Congo peacocks (Afropavo congensis) in the understory. The female was not scared at all and approached me. The male was hiding behind a bush. What a magnificent bird, in perfect view in the middle of the path right in front of me. This mythical bird was only discovered in the 1930s and only occurs in the heart of the Congolese tropical rainforest. They are related to Asian peacocks and have similar green and blue shining feathers. This was the second time I saw Congo peacocks at LuiKotale, but this time I didn’t even had to use my binoculars.
Unfortunately I was not able to take pictures, but you should definitely google it. I’m sure not a lot of white people have seen these birds in their natural habitat. Now I can say I clearly saw the bird that is featuring the cover of my African bird book. I will never forget this moment. After a while the birds disappeared in the forest.

How to catch birds the Congolese way

About a week ago three new mindele people came in. Our camp manager went to the air strip to welcome them and accompanied them on the 25km walk-in. He brought back some feathers of birds from Iyaka, the hunting camp near the savannahs. I wanted to know how the local people catch birds and which species the feathers belonged to, so I decided to go there the next day. The fishermen brought me over the river and from there I walked the 7km alone. The men at Iyaka didn’t expect a mundele that morning, but they were very friendly and I was able to use Lingala to explain what I came for. I didn’t come to judge, but was just interested in the progress of capturing birds. Nalingi komona ndengue ya bokila ya bandeke. Bowo took one of the Omphalocarpum fruits that the men had brought back from the forest. Omphalocarpum is a strictly elephant-dependent tree that produces 20cm round hard fruits attached to the stem. Only elephants are able to break open the fruits and swallow the seeds inside. When the elephants disappear from an area, the tree will eventually as well.
The inside of Omphalocarpum fruits is very sticky and the local people use is as a kind of glue. Bowo took a thick piece of wood, cut a sharp point at one side and started pounding the inside of the opened fruit. After five minutes he put the sticky mash on a big leaf and started kneading it with his hands. He removed the seed fragments and added some extra liquid to make the glue stronger. After ten more minutes the glue was ready to wrap along a small stick. The only thing you have to do next is putting the sticky stick in a tree and wait. The birds come down to sit, usually in the afternoon I was told, and can’t fly away. It’s a passive and very opportunistic way of hunting, but everything is a bonus here, I guess. It’s probably also not the most animal-friendly way of killing. The same can be said about snare traps, which are commonly used all over Central Africa. These people depend on the forest for their daily food consumption and have a different attitude to wildlife as we do. But who are we to judge their way of life. We don’t have to deal with the difficulties of life in a remote village in Congo. Instead we bring powdered milk from Ireland, sardines from Morocco and corned beef from Brazil to an isolated research camp in Congo. Spending some time in rural Africa and talking to the people makes you see things from a different perspective.
By the way, the feathers they showed me were probably of a kind of bee-eater.

Not all bonobos read the text books

About a week ago the east bonobos were nested on the west side again. We left camp at 4:35 in the morning, the latest I have left camp to go to the east group. No Bompusa crossing, no mud, no wet feet, what a luxury! By quarter past five we were at the nest site. We heard the bonobos calling before, exceptionally early, and some individuals were already up and heading towards a feeding tree 200 meters further. It took us a while to get round a big tree fall to see who was feeding in the tree. When we finally found a good spot, suddenly the whole group left the tree rapidly and there was some tumult. Five minutes later they came back and started feeding peacefully in the same tree. We saw everyone, including Rita, the subadult female who migrated into the east group during the intercommunity encounter. I just realized the group total of adult individuals was now 12, not 13 (two females emigrated, one immigrated), when Sean noticed a fourth adult male in the group. I checked, one, two, three, and four, he was right. Litono is easy to recognize, but the two other ones are more difficult, and since the end of March I hadn’t seen Dango, a male with a clear scar on his lip and a characteristic wrinkled face. Could this fourth male be Dango again? Before I could confirm his ID, half of the group again left the tree rapidly, chasing or displacing this fourth male in a subtle way. Half an hour later we lost the bonobos as they were travelling east. Probably they crossed the Bompusa soon after. We crossed the river, but didn’t find them for a couple of days. Since that day Sean and I have spent three shifts following the east group, but none of us noticed a fourth male. Today I went with Gottfried to the east. After the first feeding tree some individuals came down to the ground. We were watching one of the males that are hard to identify. I was explaining that one has round nostrils with straight lines above the nostrils, and the male we were watching has a long face, with a high upper lip. However, these face characteristics are a bit subjective and I’m still struggling to distinguish them for sure at all times.  ‘But this male has a totally different face’, Gottfried said. I took my binoculars and I agreed: ‘This is Dango!’ Bonobos are a male-phylopatric species, meaning that the males stay in the group they are born in. Sons stay with their mothers who help them getting a higher dominance status. Daughters migrate between groups, as we saw during the intercommunity encounter. But where was Dango for two months? Did he wander around on his own? Did he temporarily join another group? No one knows. What we do know is that male dispersal has rarely been observed at Lomako, an old bonobo study site. Exceptions confirming the rule? A daughter born in the west group did not disperse before giving birth to her first offspring last January. She did spend some time away from the community, or at least she was regularly not seen for a while, but a couple of months before the birth she came back permanently and mated frequently with all the males in the group. I wonder who the father of her offspring is. A lot of questions to be answered. We still have much to learn about the social behaviour of these long-lived great apes.

east and west side coming together

The following is a description of the three most memorable days since habituation of the east community began almost three years ago. After  leaving the nest site on May 11 the east bonobos started travelling west. Lambert was following the bonobos alone, as his gps batteries died.  He sent a message to camp with his last position and a direction. Just before we left camp we got a second message saying that the group  crossed the Bompusa River, so Nono and I went out on the west side of  the study area. Fourty minutes later we met Lambert on Ndjango trail. He lost the bonobos nearby. We took over and found the group near the river. I was prepared to cross the river back to the east, but instead the group travelled north and later turned west, into the range of the west community. After feeding in a couple of maku trees with plenty of fruits, the east bonobos made their night nests on the west side, 250 meter from the main trail on the west side. The following day the east group fed in the same maku trees and further travelled south. In a dense swamp they found a dead liana. The whole group fed intensively on the wood for over half an hour. Mountain gorillas are known to lick and eat decayed wood that contains high levels of sodium. Probably this is a comparable behaviour in bonobos. In the afternoon, the east bonobos backtracked their morning travel route, fed for the third time in the same maku trees and spent the night even further north and west, closer to the center of the home range of the west group. Actually, the east and west group nested only eight hundred meters from each other that night. Only the next day we would really realize how close this is for bonobos.
It took a while for the morning teams of both groups to grasp what happened that morning in the forest. The east group fed in a maku tree and slowly travelled northeast. The west group, by contrast, left the nest site early and at high speed, direction: straight east. The west researchers had difficulties keeping up with the bonobos and Lambert, following the east group, was surprised when around 7:30 am he saw a couple of females he knew from the west group! A fusion of two separate bonobo communities was happening. There was commotion, screaming, travelling. Most bonobos were lost out of sight. One of the researchers met up with Lambert, who said he had seen one of the west bonobos. Total confusion. The few (west) bonobos who stayed behind tried to catch up with the others to the east. Eventually both teams crossed the Bompusa and caught up with a couple of west bonobos on the east. In camp we got a message at 9:30 about the crossing and that Lambert was now searching on the east again. About an hour later we got a second message that confirmed the intercommunity encounter: females of both groups were seen in the same tree. We decided to all go in the forest to witness this special event. What we saw was really special. The two groups totally mixed, travelled together for about seven hours and fed in the same feeding trees. Individuals of the two groups groomed and copulated with each other. Intergroup encounters in other primate species are usually hostile, with the retreat of one of the groups ending the encounter. Each group tries to defend the resources in its home range. Chimpanzees even kill members of neighbouring communities. Why is this so different in bonobos? Do females play a special role? Female bonobos generally disperse to another community when reaching sexual maturity. Would females who associated a lot with each other during the encounter have lived together in the same group before? This is the first intercommunity encounter documented in detail at LuiKotale after more than ten years. Encounters with other, unhabituated groups must have happened before, but because the individuals of the other community will flee upon seeing humans around, it is very hard to grasp what happens during such an event. The days after the temporary mixing of both communities, the east community was missing two subadult females, but gained a new one. For the west group it was the reverse. Probably very few people have actually witnessed dispersal of subadult female bonobos between communities. Can a bonobo day get more memorable than that?


Savannah trapped in the forest

Two weeks ago the west bonobos crossed the Badzungu River entering the forest of the neighbouring village. Since the beginning of April there is an agreement with this village so we can follow the bonobos when they cross. Often it is hard to follow the group as they rush through the swampy forest along both sides of this river. During the crossing, the morning team lost the group, so that day we went out to search for bonobos on the west side of the Badzungu. We went further westward and came across a small savannah where the bonobos had been seen a couple of days before. Working in a dense forest makes you learn to appreciate an open space like this, about five hundred meters long, enclosed by forest. The moment became even more memorable when we heard bonobos from three directions as we entered the savannah. We found one of these subgroups fifteen minutes later and followed them as they walked along the forest edge. We were hoping to see the bonobos cross the open space, walking bipedally while carrying fruits, to meet up with the other group. This is the typical views of how the transition from forest to savannah happened in our early ancestors. Of course this didn’t happen (although at one point, a male was three meter in the savannah, eating Afromomum, a big herb of the ginger family) and the group travelled back east.

Last week, Niina and I went on a bird trip to lyaka, a temporary hunting camp north of the Lokoro River. The camp fisherman brought us over in a pirogue and from there it took us a bit more than an hour to get to Iyaka. A couple of hunters were staying in one of the huts and they showed us a roof where we could put our tent under. They were surprised and I felt proud that I was able to communicate with them in Lingala. Iyaka is surrounded by several extensive savannah patches that are regularly burnt to promote regrowth of grasses. We stayed for one night and made several tours in the savannah to see typical birds. Blue-breasted bee-eaters (Merops variegatus) were perched on almost every small shrub, taking off to eat flying insects now and then, and palmnut vultures (Gypohierax angolensis) were souring overhead. We saw a long-crested eagle (Lophaetus occipitalis) resting on a termite mound and in camp we had yellow-billed kites (Milvus aegyptius), fawny-breasted waxbill (Estrilda paludicola) and African grey parrots (Psittacus erithacus) as visitors. Apart from that, the ornithological value of our trip was a bit disappointing, but we enjoyed the change of habitat and surrounding.

On the first day, just before sunset, we saw a female sitatunga (Tragelaphus spekei). Sitatungas occur throughout the rain forest belt of Central Africa, but are mainly found in swampy areas and forest clearings. Forest buffaloes (Syncerus nanus) and bongos (Tragelaphus euryceros) are other species that are adapted to the open areas within the tropical rain forest. The idea is actually that these species got ‘trapped’ when the forest expanded. You should know that most of the Central African rain forest is relatively young forest. The glacial periods within the last million years have had an important impact on the distribution of forest in Central Africa. During a glacial maximum, the global climate was generally cooler and dryer, resulting in the contraction of the forest. The Congo basin was covered by extensive savannah habitat until relatively recently. In certain areas, as around Iyaka, patches of savannah still exist, although they are now maintained by people using fire. In some of these places, hundreds of kilometers away from the continuous grasslands of eastern and southern Africa, lions could be found until a couple of decades ago. The Bolobo region between the Kwa and Congo Rivers is a mosaic of forest and savannah. Last year I spent six weeks in this region and the local people I interviewed knew bushbucks, servals, side-striped jackals and even spotted hyenas (although these had not been seen for years). All of them are typical savannah species. Occasionally, a group of lions visit this region as well. Most of this is not well documented in the literature. It shows how little the scientific community knows about the basic ecology of large-bodied species in the Congo basin.

Lieven in congo

At the moment Lieven Devreese is staying at LuiKotale, a bonobo research site of the Max Planck Institute for Evolutionary Anthropology in the vicinity of Salonga National Park, Democratic Republic of Congo. Lieven is a research assistant working on habituation of a second group of bonobos and he hopes to get to see some golden-bellied mangabeys as well. Here you can read more about his 10-month adventure.