Chimpanzees and Gorillas share much of the forests of central and Western Africa. It is therefore not surprising that they might meet from time to time.
As babies, all sorts of creatures spend time together. In Gombe stream the Jane Goodall study documented Chimpanzees and baboons playing together as young.
This long lasting study in central Africa has for the first time revealed relationships between these two species that can be long-lasting and span both social and cooperative acts.
The study took place in the Goualougo Triangle in the Republic of Congo. These interactions do sometimes turn violent, particularly on the edge of the Nouabale-Ndoki National park. However, for the most part there is an area of about 100 square miles where there is a peaceful coexistence.
Most interactions between these species will last about an hour, but they have been documented going on all day (8 hours). Activities include communal eating, chasing, wrestling, play-biting and play-hitting. On one occasion a juvenile male gorilla was even seen to mount an immature female chimpanzee.
Interactions of this type have been seen before, but not studies in depth. There were 206 interactions over the 21 year study. Previous hypothesises on this, suggested that the great apes might gather together to avoid predation. However, during this study it was found that larger chimpanzee groups were more likely to hang out with the Gorillas – it is the smaller groups which are at risk from animals like Leopards snakes and even raptors.
A hypothesis put forwards by the study, posits that the Chimpanzees and Gorillas get together during foraging as well as to share information – though how is a different matter. More than half of these interactions took place at fruiting fig trees – which only fruit for 3-4 days, so it is not possible for the two species to take it in turn. Gorillas seem to have learnt to recognize the call of chimpanzees which have found a good fruiting tree source, though this doesn’t appear to work in reverse.