72 Diet and culture at Sonso
Muga who gave him some of the pith. Then Clea and a juvenile joined the group, Clea
screamed and was permitted by the males to scrape for pith. An hour after the start of
observations, Vernon joined the group and began displaying, whereat all the others left
the tree. Soon Muga and Zefa returned, Zefa begging from Vernon who three times gave
him a part of a chewed wadge. Then Zefa groomed Vernon, before starting to feed on
some inner pith loosened and dropped by Vernon.
A most fascinating possibility here is that the chimpanzees are obtaining a mild alcohol
with the pith. Local people use the tree for this purpose. They cut down a living tree,
remove a 4–6 ft length of the bark exposing the sap inside, and leave it to ferment on the
forest floor in the sunlight, returning a week or two later to take the fermented sap which
they bottle and either drink or sell as ‘palm wine’. I have tasted it and it is fairly pleasant,
rather fizzy and a bit sour but definitely drinkable. Whether any alcohol remains in the
pith after the tree has died and rotted away we have not yet discovered.
The eating of pith is not confined to Budongo. At Mahale, chimpanzees also eat the
woody pith of dry dead trees such as Pycnanthus,Ficus andGarcinia. They make a hole
at the bottom of the tree just as observed at Budongo. Raphiais not found at Mahale (for
these facts I am grateful to T. Nishida, pers. comm.).
Termite-eating and sharing
Eating of termites is well known in chimpanzees at some sites, notably Gombe, where
they eat termites of the genus Macrotermesusing twigs and branches as tools (Goodall
1986). At Budongo we don’t have the familiar large termite mounds found in more open
country, and termite-eating, while it occurs, does not form a large part of the chim-
panzees’ diet. However, here and there in the forest one comes across a termite mound,
sometimes between the buttresses of a tree or next to a tree buttress. At such sites the
Sonso chimpanzees occasionally feed on Cubitermestermites, breaking open the
mound to do so with hands and teeth. No use of sticks or other tools for ant or termite-
eating has so far been seen in Budongo, whereas this is common in other sites such as
Gombe, Bossou, Taï and Assirik (McGrew 1992).
Newton-Fisher (1999b) has described termite-eating and sharing by Sonso chimpanzees:
The sharing of termites was observed on 28 August 1995. From 08.15 hours Field assistant Geresomu
Muhumuza and I had been watching a relatively large mixed-sex foraging party of eleven individu-
als. After 10.15 hours the party began to fragment. Four of the community’s twelve adult males (MG,
MA, JM, KK) and a juvenile male (GS) travelled north, away from the other party members, along
one of the trails...(past) a small termite mound. This mound housed Cubitermes speciosus.
At 11.15 hours, first MG, and then JM wrenched lumps of earth from the mound and fed on the
termites. The chimpanzees used their lips to pick the termites from what had been the inside sur-
face...MG moved 2 m to the north of the tree carrying his lump of termite-ridden earth. KK pant-
grunted softly as he approached MG, who in response divided the fragment of termite mound in
two, handing one part to KK. Both males sat and fed on the termites. No tools were used to acquire
the termites (Newton-Fisher 1999b: 369–70).