“COTABAMBAS OFERTA BIENES Y SERVICIOS COMPETITIVOS PARA EL MERCADO LOCAL Y REGIONAL”

5.2.1 The chimpanzees of Ngamba Island

In 1998, CSWCT was founded to move chimpanzees living in overcrowded conditions at Entebbe Zoo (UWEC) to Ngamba Island. These individuals were all rescued by the Uganda Wildlife Authority as orphans of the bush-meat trade and live animal trade from Uganda and sunounding countries, and make up the adult group at the sanctuary. Since this first group was moved to the island, many more orphans have been rescued. Most of the arrivals since 1998 have been young chimpanzees from the Democratic Republic of the Congo, who were confiscated at border towns around Uganda. These individuals are mostly under 8-years-old, and make up the juvenile group at the sanctuary. This group is housed separately from the adults due to prior complications with integration attempts. All the

chimpanzees on Ngamba are from the subspecies Pan troglodytes schweinfurthii. The age of

each individual was estimated upon arrival to the sanctuary on the basis of dental emption, size, weight and motor co-ordination. Unfortunately little is known about the history of each chimpanzee before they came to Ngamba (see Appendix A).

Before being integrated into the Ngamba community, new arrivals must spend tlrree months in quarantine on the mainland. During this period the chimpanzees are cared for by a human suiTogate parent. All ‘chimp parents’ are trained to use chimpanzee-typical gestures and vocalisations, such as the pant-hoot greeting, food giniits, fear calls, play faces and how to tickle and groom effectively. Great emphasis is placed upon using these behaviours in order to facilitate the young chimpanzee’s integration into the sanctuary gioups once the quarantine period has been completed.

5.2.2 The chimpanzees ’ daily routine

On the island the adult group spends all day in the forest. Whilst in the forest they are able to play, forage, nest build and perform many of the activities of a wild chimpanzee community. However, the endemic vegetation of the island is not sufficient to support the community, so they are provisioned five times per day with a variety of finit and vegetables as well as seeds, nuts, eggs and porridge (see Figure 5.4a).

Figure 5.4 (a) Top picture - Members o f the adult group spend the majority o f each day in the forest. They are provisioned five times each day, and come out o f the forest to the electric fence, where staff throw food from a viewing platform that runs across the top o f the fence

(b) Bottom picture - Members o f the juvenile group remain in the holding facility while the adults are in the forest. Young chimpanzees receive milk in cups, as well as the usual food items each day.

The juvenile group spends the majority of each day in the holding facility while the adults are in the forest (see Fig. 5.4b). The holding facility consists of six rooms of varying size that are interconnected via a series of raceways and sliding doors (see Fig. 5.5). Chimpanzees enter and leave the holding facility though a tunnel that leads out into the forest. The tunnel entrance is locked each day while the adults are in the forest. Whilst in the holding facility, the juvenile group receives many behavioural enrichment activities in the form of simulated foraging tasks, and novel objects.

Figure 5.5 The holding facility at Ngamba Island. The research room is located at the far left o f the picture. The hammocks in which the chimpanzees sleep at night can be seen hanging from the roof.

At night the adult group returns from the forest, and all the chimpanzees sleep in hammocks inside the holding facility (see Fig. 5.5). The chimpanzees choose to return each night, as the facility provides much needed protection from the frequent tropical storms that hit the island. This system enables the juvenile group to have access to the forest before the adults leave the facility in the morning, and after they have returned in the evening. During these trips into the forest the youngsters are often accompanied by adult female chimpanzees, who in many respects take over the role of a surrogate mother. Like the adult group, the young chimpanzees are free to perform many of the natural activities of a wild community.

5.2.3 The issue o f enculturation

A number of authors have argued that extensive human contact can lead to a fundamental change in an individual’s socio-cognitive development through increased exposure to objects with specific functions, increased opportunity to observe human demonstrations, attention focusing through training, and being treated intentionally (Premack, 1983; Tomasello, Kinger et al., 1993; Tomasello, Savage-Rumbaugh et al., 1993; Call & Tomasello, 1998). General arguments against this view were discussed in section 2.5.4. Nevertheless, it might be suggested that the chimpanzees of Ngamba Island are enculturated, and therefore that the findings of this thesis cannot be generalised to chimpanzees as a whole.

However, the chimpanzees of Ngamba Island experience very few ‘human’ objects with specific functions. Any objects that are introduced act as a form of enrichment and chimpanzees do not receive demonstrations or training about how the objects should be manipulated. The chimpanzees spend the majority of time in a peer group with daily excursions into the forest with adult female conspecifics, and are rarely one-on-one with humans (with the exception of the tluee-month quarantine period). However, gieat care is taken to interact with the chimpanzees using chimpanzee-typical gestures and vocalisations.

When in contact with humans, the chimpanzees are treated as intentional individuals, but the

influence of this interaction is less intense than would be experienced by a home-raised ape. Therefore the chimpanzees of Ngamba cannot be considered as ‘enculturated’ in the same sense as some studied by other researchers (Tomasello, Savage-Rumbaugh et al., 1993; Bering et al., 2000; Bjorklund et al., 2000; Bjorklund et al., 2002). Instead, the stimulation that is received on Ngamba Island could be viewed as a replacement for the rich social and physical enviromnent that would be experienced in the wild.

The rearing history of the Ngamba chimpanzees, and in particular the juvenile group, can be seen as a mixture of nursery housing, coupled with the daily opportunity to interact with adult conspecifics in a species-typical forest environment. The Ngamba chimpanzees are not enculturated, and therefore the results of this thesis are likely to have implications for chimpanzee cognition in general.