To carry out the research, the scientists spent several months observing two different groups of 50 southern pig-tailed macaques (Macaca nemestrina) in Segari, Malaysia. In this way, the researchers were able to observe that, every day, the groups they walked for about three hours from the rainforest to the plantation.
In addition, the scientists wanted to find out the differences in the behavior of primates when they were in the rainforest and when they accessed the palm oil plantation. Although both groups had an abundance of food (in the form of fruits and rats) they were also more likely to conflict with humans.
However, the study focused on aggressive interactions, behaviors that promote relationships (such as grooming or play) and social media within different groups (such as mother-child relationships).