PRIMATES

Primates Id code: amd083

Hominidae
Pan paniscus

Schwartz, 1929

(Eng) Bonobo or pygmy chimpanzee

(Fre) Chimpanzé pygmée

Taxonomic notes

No significant taxonomic notes.

IUCN threat category

Listed as Endangered (EN: criteria A2cd).

Available information

Although less studied than the other two hominid species, information available on the ecology of the bonobo is good. The use of patches of marsh grassland in the rain forest at Yalosidi (former Zaire) is described in Uehara (1990)). Feeding habits, predatory behaviour, and foraging strategies were investigated by Ihobe (1992), Malenky & Wrangham (1994), and Sabater & Veà (1994), who did research on the species at Wamba (former Zaire), Lomako Forest (former Zaire) and Ikela (former Zaire). Aspects of the species' behaviour are discussed in Idani (1995). The main aspects of the ecology of the species are described in Dunbar (1988), Badrian & Badrian (1977) and Susman (1984). Data on its distribution are found in Colyn (1987), Kano (1984), and Verschuren (1975). Status, threats, and conservation issues are discussed in MacKinnon (1976), Malenky & Susman (1989), Mittermeier (1986), Mubalamata (1984) and Oates (1996).

Known extent of occurrence

The species occurs in the central Zaire basin, between the Zaire River, the Lomami River, the Kasai/Sankuru Rivers and the Lake Tumba/Lac Ndombe area. The map of its distribution in former Zaire was obtained from Oates (1996) and later corrected to match the river network as shown in a detailed map in Kingdon (1997). Depierre & Vivien (1992) report the species as occurring in the south-eastern part of Cameroon, but as this the only available record in the area, it has been cautiously neglected in this databank. (Fig. 2.4.2.a)

Categorical-discrete (CD) distribution model

This species inhabits a mosaic of swamp, primary and secondary forests (Kingdon, 1997; Stuart & Stuart, 1997; Badrian & Badrian, 1977).

Based on these environmental preferences, the following scores were assigned (Fig. 2.4.2.b) (Tab. 2.4.2.a):

Score
1	Primary, secondary and swamp forests.
2	Degraded forest and forest mosaics.
3	Savannas and croplands.

suitable		moderately suitable		unsuitable		Total
km²	%	km²	%	km²	%	km²	%
340 976	85	41 006	10	20 950	5	402 932	100

Tab 2.4.2.a: Cumulative size (km²) of areas pertaining to each environmental suitability class within the Extent of Occurrence.

	Number Patches (NP)	Mean Patch Size (MPS) km²	Patch Size SD (PSSD) km²	Largest Patch Index (LPI) %	Mean Shape Index (MSI)	Area-Weighted Mean Shape Index (AWMSI)
suitable	22	15 536	70 815	88.88	1.84	13.76
moderately suitable	384	106	630	3.16	1.22	3.92
Total AO	6	63 763	142 421	99.91	2.35	7.52

Tab 2.4.2.b: Area of Occupancy fragmentation indexes.

Probabilistic-continuous (PC) distribution model

The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.4.2.c.

Validation

No occurrence of the species within the four sample areas.

Comments and conservation issues

The known EO is largely classified as suitable for the species. Although the EO appears to be compact within the central forest block of former Zaire, the moderately and unsuitable areas are more frequent in the central part of the EO and along the eastern section. The LPI shows that at least one large patch of suitable areas is available, accounting for 88.88% of the total AO, but the AWMSI also shows that the shape of the AO is indented. The species is actually strongly reduced in presence and densities as a consequence of direct human persecution and pressure. About 8.1% of the total AO is included in existing protected areas and the species is classified as Endangered. The amount of protected areas (less than 30 000 km² in total) appears far too small to ensure the conservation of the species even if they were able to provide effective protection.

SUITABILITY CLASS	inside	outside	Total
suitable	6.22	78.40	84.62
moderately suitable	1.52	8.66	10.18
unsuitable	0.80	4.40	5.20
Total	8.54	91.46	100

Tab 2.4.2.c: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.

References

Badrian A., Badrian N. (1977). Pygmy chimpanzees. Oryx: 13(5), 463-468.

Colyn M.M. (1987). Les primates de la foret ombrophile de la Cuvette du Zaire: interprétations zoogéographique des modèles de distribution. Rev. Zool. Africaine: 101, 183-196.

Depierre D., Vivien J. (1992). Mammifères sauvages du Cameroun. Ministère de la Coopération et du Développement. Cameroun.

Dunbar R.I.M. (1988). Evolution of social systems. In: Dunbar R.I.M. (Ed.). Primate Social Systems. Croom Helm Publishers Ltd, London: chap. 13: 292-325.

Idani G. (Ed.) (1995). Function of peering behavior among bonobos (Pan paniscus) at Wamba, Zaire. Primates: 36(3), 377-383.

Ihobe H. (1992). Observations on the meat-eating behavior of wild bonobos (Pan paniscus) at Wamba, Republic of Zaire. Primates: 33(2), 247-250.

Kano T. (1984). Distribution of Pygmy Chimapnzees (Pan paniscus) in the central Zaire basin. Folia Primatol.: 43, 36-52.

Kingdon J. (1997). The Kingdon field guide to African Mammals. Academic Press, London and New York: Natural World.

MacKinnon J. (1976). Mountain gorillas and bonobos. Oryx: 13(4), 372-382.

Malenky R.K., Susman R.L. (1989). Conservation status of Pan paniscus. In: Heltne P.G., Marquardt L.A. (Eds). Understanding Chimpanzees. Harvard University Press: Cambridge, U.K: pp 362-368.

Malenky R.K., Wrangham R.W. (1994). A quantitative comparison of terrestrial herbaceous food consuption by Pan paniscus in the Lomako Forest, Zaire, and Pan troglodytes in the Kibale Forest, Uganda. Am. J. Primatol.: 32(1), 1-12.

Mittermeier R.A. (1986). A global overview of primate conservation. In: Else J.G., Lee P.C. (Eds). Primate ecology and conservation. Selected Proceedings of the 10th Congress Int. Primatological Society, Nairobi, Kenya (July 1984). Cambridge University Press, Cambridge, U.K: chap. VI.7, 325-341.

Mubalamata K.K. (1984). Will the Pygmy Chimpanzees be threatened with extinction as are the Elephant and the White Rhinoceros in Zaire?

Oates J.F. (1996). African Primates Status Survey and Conservation Action plan. IUCN/SSC Primate Specialist Group.

Sabater J., Veà J.J. (1994). Comparative inventory of foods consumed by the wild pygmy chimpanzee (Pan paniscus; Mammalia) in the Lilungu-Lokofe region of the Republic of Zaire. J. African Zool.: 108(4), 381-396.

Stuart C., Stuart T. (1997). Field guide to the larger mammals of Africa. Struik Publishers.

Susman R.L. (Eds) (1984). The Pygmy Chimpazee: Evolutionary Biology and Behavior. Plenum Press, New York.

Uehara S. (1990). Utilization patterns of a marsh grassland within the tropical rain forest by the bonobos (Pan paniscus) of Yalosidi, Republic of Zaire. Primates: 31(3), 311-322.

Verschuren J. (1975). Wildlife in Zaire. Oryx: 13(2), 149-163.