(Blumenbach, 1775)

(Eng) Chimpanzee

(Fre) Chimpanzé

Pan includes two extant species: P. troglodytes and P. paniscus. There is considerable confusion with regard to the number of geographic races that warrant subspecific recognition (Jones et al., 1996). According to Oates (1996) three subspecies are widely recognised, namely P. t. schweinfurthi (Eastern chimpanzee) between Tanzania and former Zaire; P. t. troglodytes between former Zaire and Nigeria and P. t. verus (Western chimpanzee) between Togo and Senegal.

Listed as Endangered (EN: criteria A2cd) both as a species and as P. t. troglodytes; Endangered (EN: criteria A1cd+2cd) as P. t. schweinfurthi and as P. t. verus.

Chimpanzee is among the most studied mammal species in the world, and literature available is very conspicuous. Only a selection of the references available is reported here. Comprehensive sources of information of the ecology of this species are Goodall (1990), Jones et al. (1996), and Heltne & Marquardt (1989). A review of the literature available on this species up to 1973 is found in Balwin & Teleki (1973). Feeding habits and social behaviour were investigated in the Kigoma and Mpanda District (Western Tanzania) by Suzuki (1969); the author also gives a quite detailed description of the habitat in which the species was observed. This is one of the few studies on this species in savanna woodland. Boesch (1994), Boesch & Boesch (1989) and Wrangham & van Z. B. Riss (1990) focused on its diet and predatory behaviour. Population numbers, structure, and dynamics are analysed in Hashimoto (1995) and Sugiyama (1984), who conducted their study in the Kalinzu Forest (Uganda) and at Bossou (Guinea) respectively. A study on the use of first growth and secondary growth forest was carried out by Fimbel (1994) at Tiwai (Sierra Leone). Coexistence and niche separation with gorillas are briefly discussed in Yamagiwa (1995), who did research on those species in the Kahuzi-Biega National Park (former Zaire), and in Tutin & Fernandez (1985). The most studied aspect of the species’ ecology is its behaviour and literature available on the matter is vast. A quite complete description of its social behaviour is found in Dunbar (1988). The use of hands and tools is analysed in Boesch & Boesch (1990) and Marchant & McGrew (1996), who both investigated the species at Gombe National Park (Tanzania). Boesch & Boesch (1990) also report some data from Tai National Park (Ivory Coast). Vocalisation and differences between sexes are described in Mitani & Gros-Louis (1995). Goodall (1979) reports accurate data on cannibalistic behaviour observed at Gombe (Tanzania). The species’ distribution and population numbers are constantly monitored, and updated data are reported in Oates (1996). Further information on its occurrence and status are available for Gabon (Blom et al., 1992), Ghana (Booth, 1979), Ivory Coast (Marchesi et al., 1995), Rwanda (Monfort, 1992), Tanzania (Goodall, 1989), Uganda (Huggard, 1994; Plumptre & Reynolds, 1996), Nigeria (Osemeobo, 1988), part of Cameroon and Congo (Mitani, 1990) and former Zaire (Colyn, 1987; Verschuren, 1975; Rahm & Christiaensen, 1966). The authors mentioned above also give some information on the habitat in which the species is found. Coe (1975) reports data on its occurrence on Mount Nimba (Liberia) and includes a detailed description of the vegetation of the area surveyed. General information on the species’ ecology and distribution is found in Clutton-Brock (1977), Kingdon (1997), Tuttle (1990), Stuart & Stuart (1997), and Wrangham & van Z. B. Riss (1990). Status, threats and conservation issues are discussed in Bearder (1991), Mittermeier (1986), Oates (1996), Struhsaker (1981), and Teleki (1988).

The distribution map was obtained from Oates (1996) and adjusted to match the river network using Kingdon (1997). The species is discontinuously distributed in the west African forests and better represented in Central Africa, from south Cameroon to eastern former Zaire, north of the Zaire River, and eastward to Uganda. Separate populations also occur in southern Sudan and western Tanzania (see Fig. 2.4.3.a).

This species is mainly found in forest and forest galleries; it also occurs in moist woodland savanna (Teleki, 1988; Kingdon, 1997; Stuart & Stuart, 1997; Haltenorth & Diller, 1980).

Based on these environmental preferences, the following scores were assigned (Fig. 2.4.3.b) (Tab. 2.4.3.a):

The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 2.4.3.c.

The overall EO of the species, even though divided into several parts, is still quite large (1.85 million km²). It is also mostly suitable, confirming that the species is affected more by direct human persecution than habitat destruction. Being a large and charismatic species, its EO is drawn with greater accuracy and the fragmentation of the EO in Fig. 2a shows the level of knowledge of the species’ distribution. Also the Index of Accordance which scores as high as 82.76%, shows that the available information on the species’ ecology is quite adequate for deriving the CD model. Within the EO, the species occurs with patchy distribution possibly due to human pressure: this is the case of Guinea and most of the small areas in western Africa, as well as the eastern parts of the range, where interspersion with less suitable areas is more frequent (see both models). Fragmentation of suitable areas is more severe there, reducing the size of potentially suitable zones for the species. The stronghold for the species is the central large patch of suitable areas. About 6.5% of the total AO is included in the existing protected areas throughout the EO: this percentage is certainly not distributed in a uniform manner and it will be useful to analyse the way they cover the various EO fragments. The species as a whole is classified as Endangered, although some local populations are obviously in much worse conditions: as a general guideline, conservation should be focused where there is the greatest probability of contributing the largest possible benefit to the species and not where the last animals of an isolated patch one to be saved.