Source: Kalan, A. K., Kulik, L., Arandjelovic, M., Boesch, C., Haas, F., Dieguez, P., … & Michael Fay, J. (2020). Environmental variability supports chimpanzee behavioural diversity. http://researchonline. ljmu. ac. uk/id/eprint/14322.
This study identified that environmental variability had a more important effect on chimpanzee behavioural diversity, than climate or habitat stability. It suggests that the need to adapt to an more unstable environment is a driving factor behind displaying a wider range of behaviours. The alternative could also be true, in that those living in the forests have lost their behavioural diversity.
It has also been identified that those living in, or close to the Pleistocene forest refugia (Stable environments with higher biodiversity), display less behaviours than those further out. Due to the stable nature of the refugia, those populations do not need to adapt and so display a lower behavioural diversity.
Those living in the savannah woodland have adapted to drier conditions through a wide-ranging diet and thermoregulatory behaviour, something which was not observed in the forest communities.
This represents a potential concern regarding climate change, in that the forest-dwelling chimpanzees may suffer if those forests turn to savannah woodland. I wrote about this in my last post, but this ecological change is currently happening in the Amazon Basin. Western Africa is also one of the areas that will be most affected by climate change.
In conclusion, chimpanzees exhibit a greater behavioural diversity in environments with more variability. Distance from Pleistocene forest refugia was associated with a larger number of behavioural traits, including both tool and non-tool use behaviours.