Chimpanzees of the Budongo Forest : Ecology, Behaviour, and Conservation

214 The Kasokwa Forest chimpanzees

find out what threats they faced from the local population and to what extent they

engaged in crop-raiding on the sugar cane fields next to their forest, and try to work out

how their survival could be ensured. He would observe them and make notes on them

following the methods used by our field assistants at Sonso, and he would interview

local people about them.

Since that time we have been collecting data on the Kasokwa chimpanzees. It appears

they are confined to the Kasokwa riverine strip and the surrounding area which consists

of gardens, farmers’ fields and the Kinyara sugar plantation.

They subsist mainly on forest foods but are forced out of their little forest strip by

food shortages there, and at such times they engage in crop-raiding. They have also been

seen to hunt black and white colobus monkeys, and once, when they were successful, to

eat the meat. Kyamanywa (2001) notes that females take part. He writes

Both male and female (subadults and adults) participate in hunting. Some go and lay an ambush on

the ground while some of the juveniles go up the tree where the prey are and try to provoke them,

shaking the branches. In turn the prey, especially black and white colobus monkeys, chase the

chimpanzees but are clever not to go down to the ground where the ambush is.

Tool-use by Kasokwa chimpanzees

The Kasokwa chimpanzees make leaf sponges to drink water, as the Sonso chimpanzees

do. Also, like the Sonso chimpanzees, they eat honey, using sticks to obtain it.

However, this attempt has proved dangerous as bees retaliate and bite or sting the chimpanzees

forcing them to jump from a high tree to the ground. This is common with males (adult and subadult).

They have also been observed, especially the males, carrying stones in their hands coming from crop

raiding. But what they use the stones for is not clear. Perhaps it is a kind of defence in case they are

attacked by humans while leaving the gardens after crop raiding (Kyamanywa 2001).

They feed in the Kasokwa forest when fruits are available, and have leaves, shoots

and flowers as alternative foods. However, sufficient food is not always to be found, at

which times they move out into the sugar cane to feed. They also visit local gardens to

take paw-paws and mangoes. Kyamanywa (2001) writes:

During mango fruiting seasons, they spend most of their day time feeding on mango fruits in vil-

lages around the forest. This happens mainly between 8.0 a.m. and 11.30 a.m. for the morning

peaks and between 3.30 p.m. and 5.30 p.m. for the afternoon peaks...they cross through home-

steads and feed on mangoes in gardens where people are farming. This exposes them to the danger

of people throwing stones at them, hence in that way making them aggesssive.

Unlike the Sonso chimpanzees, the Kasokwa chimpanzees keep silent most of the

time. They do not engage in the loud pant-hoot choruses characteristic of the Sonso

chimpanzees. Kyamanywa speculates that this is because they live near people and fear

them, and so they try to keep hidden as much as possible. He himself had some difficulty