Presence of Great Apes in Bas-Congo
The Democratic Republic of the Congo (DRC) has more great apes, in terms of both individuals and taxa, than any other range state (based on known distribution and on the area of suitable habitat). An estimate for the number of individual apes must await the results of extensive field surveys, but even number of taxa has been open to question for some years. This is because of the uncertainty surrounding the continued survival of western lowland gorillas and central chimpanzees in the Bas-Congo region of DRC, adjacent to the Angola (Cabinda enclave) and Congo (Brazzaville) border, north of the mouth of the River Congo. The recent reclassification of chimpanzees in the south east of the country as a new sub-species has increased the number of recorded taxa to 7, if both Bas-Congo subspecies are confirmed to be present.
Great apes recorded in DRC
- bonobo, Pan paniscus, endemic to the central region, south of the curve of the River Congo, and north of the rivers Kasaï and Sankuru,
- mountain gorilla, Gorilla beringei beringei, Virunga Volcanoes on DRC's eastern border with Rwanda and Uganda,
- eastern lowland or Grauer's gorilla, Gorilla beringei graueri, found in the three provinces of Grand-Kivu and Ituri, in the east of the country; also endemic to DRC,
- western lowland gorilla, Gorilla gorilla gorilla, formerly known to be present in the Mayumbe region of Bas-Congo, but suspected by some to be extinct in DRC,
- central chimpanzee, Pan troglodytes troglodytes, reportedly surviving in Bas-Congo, notably near the Kuimba Mission and in/around the Luki Biosphere Reserve (confirmed in 2005, Inogwabini, pers. comm.) in forests contiguous with those in Cabinda and Congo (Brazzaville),
- eastern chimpanzee, Pan troglodytes schweinfurthi, widespread in the north of Equatorial and Oriental Provinces and east of the River Congo (Ituri, North Kivu, South Kivu*, Maniema* and Katanga* - asterisk denotes former taxonomy, see below),
- *A newly described subspecies, Pan troglodytes marungensis, now includes all the DRC chimpanzee populations south of Rutshuru down to Marungu (Groves 2005).
Gorillas in the Mayumbe region were considered to have survived "at
least until the 1960s" but were thought to be "almost certainly
extinct" by Verschuren (1975), cited in Lee et al. (1988). The possibility
of individuals occasionally entering from Cabinda and from Congo Brazzaville
was acknowledged, but no confirmation was forthcoming.
At the DRC National Workshop on Great Apes in 2002, it was considered
a priority to survey the forests of Mayumbe and Bas-Uele (Ndembo Longo
2002). Despite this, no surveys have been carried out until now. Notes
on the reported presence of apes in the region were provided by zoologists
Omari Ilambu Omer and Inogwabini Bili-Isia of WWF, who had visited the
region in 2001, and seen a skin of a gorilla shot in 1996 in Tsanga Nord.
WWF teams have now surveyed the Luki Biosphere Reserve, south of the target
area, finding chimpanzees but not gorillas (Inogwabini, pers. comm.).
Prior to the GRASP (Great Apes Survival Project) Inter-Governmental
Meeting (IGM), a four-day trip to Tshela and the surrounding region of
Bas-Congo was undertaken to ascertain which great apes survive there.
Following this encouraging reconnaissance, the need for a more detailed
survey was listed in the DRC National Great Ape Survival Plan (NGASP,
published September 2005). A second visit to the region was carried out
in May 2006, including a walk across the Madiakoko forested chain of mountains
that protrudes into DRC from Cabinda. A questionnaire-based survey of
more villages in the region has been undertaken by François Ntedika,
and a more detailed census of apes in the Madiakoko Mountains is planned.
A summary of gorilla reports in recent years (Omari and Inogwabini, pers.
comm.):
Kivinda - claims of gorilla reported in 2000,
Tsanga-Nord - gorilla killed in 1996, skin seen by Omari and Inogwabini
in 2001.
Method
In 2005, I travelled by air to Matadi, by road to Boma and north to Tshela,
aided by the DRC Ministry of Environment, Nature Conservation, Water and
Forests. With the assistance of François Ntedika, the Tshela District
Coordinator for Environment, 2 days were spent on motorbikes visiting
villages on the edge of likely forests and interviewing village chiefs,
hunters and farmers. Courtesy calls were made to regional officials, during
which the purpose of the trip was explained in the context of the GRASP
NGASP and IGM.
GPS readings were taken in the centre of each village, at the river on
the Angola border and at a recent chimpanzee nest site. We visited Konde-Phemba
first because a leopard had been reported killed there in August, which
suggested there were still areas with wildlife populations close by.
Results from 2005 visit
No news of gorilla sightings were found in Tsanga-Nord, and it seems likely
the species is no longer found in this area, which is largely cultivated
now.
In the village of Konde-Phemba (47.5 km north of Tshela, altitude 1,000
ft), we were told that gorillas are occasionally seen in the rainy season
when nuts are fruiting (October-December). Last year, Mme Lidi saw a lone
silverback in her fields. In the late 1990s a 12-year-old girl was killed
by a silverback when a woman and her two children disturbed him while
working in their fields - the mother ran to grab her baby and fled, but
the girl was left behind and was attacked, later dying of her injuries.
This occurred about 6 km east of here. The mother has since moved to live
in Congo Brazzaville.
Discussion with the men convinced me they knew the difference between
chimpanzees and gorillas, and that gorillas often nested on the ground,
whereas chimpanzees nest in trees. To the north-east was a forested chain
of mountains called Madiakoko, which everyone agreed was the best place
to find gorillas.
In the village of Tsina Kongo, (3 hours west of Tshela, altitude 650 ft),
near the forest of Mabuba (to the west, NW and SW), M. Kumbu-Kiza told
us he had not seen gorillas since 1977/78 when many animals crossed over
the dried up River Tshiluango to Cabinda during a drought. Chimpanzees
are still here, and elephants come every year in the rainy season, October-December.
We continued west to village of Kayinzobe. There, M. Mbatshi-Mavungu Boniface,
Chef de Groupement, told us he knows of a community of chimpanzees in
the forest to the west. No gorillas now, but there were when he was young
- the forest guards spoke of them. We walked to the river bank - on the
Cabinda side there was forest and no signs of human activity, but I was
warned that the border is patrolled and that this made it unsafe to cross.
On our way back, we met a farmer, M. Mavungu-Muanda, who led us to a patch
of forest virtually surrounded by fields, in which a group of fewer than
10 chimpanzees had stayed for about 3 weeks in late July/early August.
We eventually found and photographed nests. He explained that Muyumbe
people do not eat chimpanzees or gorillas for fear that it would lead
to them giving birth to one. Hunters do not set snares, but just use a
shotgun. From this, it would seem that loss of habitat to agriculture,
and shooting crop-raiding apes, is the primary reason for the decline
in numbers.
Time did not allow a visit to Kivinda to follow up the claims of gorilla
sightings in 2000.
Results of 2006 visit
From Kinshasa I flew to Matadi on 27th May, and was met by M. Gaby (the
Minister's GRASP representative for Bas-Congo). We headed towards Tshela,
spending the night en-route. On Sunday morning we met up with Ntedika
in Tshela and hired motorbikes to head up to the forest of Madiakoko.
We spent the night in the village talking to hunters and walked across
the mountains the next day. We saw chimpanzee nests but were unable to
reach the area where gorillas are reported in the time available. We were
picked up by M. Gaby and returned. The discussions with the hunters revealed
that some gorillas reside permanently in DRC, but others cross the border
seasonally from Cabinda. They feed on nuts in the deeper forest in the
rainy season and come to the forest edge - where they are more often seen
in fields - during the dry season (May-October).
François Ntedika has written a very useful report on his survey
in 13 villages, along with accounts for the first sum of BFF funding.
He signed for US$ 1,000 which will enable him to extend his surveys to
several other villages (and also develop the film of photographs taken
during the earlier work).
On my return to Kinshasa I passed on a photocopy of the report to Inogwabini
who was planning to visit François Ntedika and deploy his census
teams in the most promising parts of the forest. We should have confirmation
of presence of gorillas in this part of DRC in the coming weeks. The DRC
government has expressed an interest in pursuing the idea of a tri-national
protected area with Angola (Cabinda) and Congo Brazzaville.
Map of Bas-Congo with the sites where great ape traces
were found
(asterisks). 1: Konde-Phemba, gorilla reported; 2: Tsanga-Nord, gorilla
veri. cation; 3: Tsina Kongo, chimp nests; 4: Kivinda, claims of gorillas;
5: Lusanda-Sundi, chimps captured
Conclusion
From these preliminary visits, we can conclude that fragmented pockets
of forest still support a chimpanzee pop-ulation of sorts even in cultivated
areas (viability unknown), but that gorillas only survive in the larger
areas of surviving forest. Killing of crop-raiding apes and habitat loss
seem to be the main causes of the decline in great apes here, but a concerted
conservation education effort might be able to reverse the decline - particularly
if attitudes to apes could be made more positive.
François Ntedika is willing to continue interviewing villagers
to establish the most promising forests for apes, and, based on his results,
a full census of the most promising forest blocks should follow. The possibility
of creating community reserves, trans-frontier protected areas and other
conservation activities can then be assessed in order to protect this
important population of gorillas and chimpanzees.
This gorilla population is of particular importance both nationally and
internationally. At the national level:
- The confirmation of extant Gorilla gorilla gorilla and Pan troglodytes troglodytes populations in the country is an important fact for DRC's NGASP and Biodiversity Strategy and Action Plan.
- The political impact of gorillas being in the west of DRC must also be recognised. To date, gorillas and the revenues generated by gorilla tourism have been seen as relevant only to eastern DRC, with all the problems associated with Kivu Province. If the Government is made aware of the potential for such development, we can anticipate strong support.
At an international level, these populations are probably not numerically
highly significant, but they are of genetic interest, being the furthest
south populations of both taxa. Moreover, as discussed at the IUCN Workshop
on Central African Apes (Brazzaville, May 2005), the threat of Ebola is
most severe in areas with high population density of great apes; thus,
small, isolated populations such as these present the best hope of survival
in the event that Ebola (or other contagious diseases) cause a population
crash in areas previously thought to be strongholds of the species.
Finally, the recent inclusion of all gorillas in Appendix I of the Convention
on Migratory Species and the transfrontier nature of this population indicate
that this could become the subject of a tripartite conservation agreement
between DRC, Angola and Congo Brazzaville.
Ian Redmond
My stay in DRC to help complete the NGASP and assist in preparing for the IGM was supported by the Born Free Foundation and UNEP, through GRASP. The DRC Government facilitated my mission, and covered the cost of the return air fare and the vehicle to Tshela in 2005; I thank the Secretary General of the Ministry of Environment, Nature and the GRASP Focal Point in DRC, M. Leonard Muamba, and the Minister's representative in Bas-Congo, M. Gaby. I am grateful to Lisa Steel of WWF for the use of her GPS, and to Omari Ilambu Omer and Inogwabini Bili-Isia of WWF for their information and guidance.
Ian Redmond is a wildlife consultant specializing in apes and elephants; he began his fieldwork in 1976 as Dian Fossey's research assistant at Karisoke and visits the Virungas every year. He is Chairman of the Ape Alliance.
References
Lee, P. C. et al. (1988) Threatened Primates of Africa, The IUCN Red Data
Book. IUCN, Gland, Switzerland and Cambridge, UK
Ndembo Longo, J. (2002) Rapport General, Atelier sur la Survie des Grands
Singes en RDC
Verschuren, J. (1975) Wildlife in Zaire. Oryx 13, 25-33; 149-163