Chimpanzees in the wettest part of Rwanda seem to plan ahead for bad weather
New study suggests that chimpanzees are anticipating what the weather has in store for them when they build their nests
A new study from a project led by Dr Cyril Grueter, Associate Professor in Evolutionary Anthropology, has explored how chimpanzees in Rwanda’s Nyungwe National Park change their nest building behaviour depending on climatic conditions.
Chimpanzees build a new nest every night. Previous studies have shown how nest structure and location vary in warmer, drier areas, but this is the first study to look at nesting behaviour in the wet, cool, highly changeable habitat of montane forests. Researchers found that on wetter nights the chimpanzees chose taller trees with thicker canopy cover. In cooler conditions they built deeper, thicker nests to keep themselves warm.
Crucially the results indicate that the chimpanzees are not just responding to the conditions at the time they are building the nest but are building nests that take account of conditions later at night. It could mean that chimpanzees are planning ahead, anticipating what the night will bring, rather than just reacting to the here and now. Whilst the study does not provide proof that chimpanzees can predict the weather, it is an important indicator that they may be responding to environmental cues.
This study opens the door to further research, into what specific weather cues chimpanzees might detect and, investigations to clarify if this behaviour is widespread or distinctive to chimpanzees living in particularly variable conditions. The sort of highly flexible behaviour demonstrated by these chimpanzees requires complex cognitive processes. Processes which may have evolved in response to environmental challenges. At a time when chimpanzees, like all animals, face increasing environmental challenges, new insights into how they cope with changing conditions are vital.
“By studying how chimpanzees cope with changing and uncertain conditions, we gain a window into the kinds of challenges our own ancestors faced and the mental skills they may have evolved to deal with them.”
Dr Cyril Grueter
Read the full Current Biology article
Chimpanzee in Nyungwe. Photo by Cyril Gruete
Nyungwe chimpanzee in nest. Photo by Hassan Al Razi
Nyungwe chimpanzee in nest. Photo by Samantha Green
