Interactions between chimpanzees and gorillas have so far been considered as relatively relaxed.

Simone Pika

Self-medication — where individuals use plant parts or non-nutritional substances to combat pathogens or parasites — has been observed across multiple animal species including insects, reptiles, birds and mammals, current Biology.Bears two closest living relatives, chimpanzees and bonobos, for instance, swallow leaves of plants with anthelmintic( antiparasitic) properties and chew bitter leaves that have chemical properties to kill intestinal parasites.

Chimpanzees eat insects but we did not know that they catch and use them to treat their wounds, hence, they not only have an understanding of their food species( plants, insects, monkeys, birds, reptiles) but probably also about characteristics of other animal species that help to act against injuries.

This is, for me, especially breathtaking because so many people doubt prosocial abilities in other animals, suddenly we have a species where we really see individuals caring for others.

We do not know whether the observed behavior involves empathy, we know that it may qualify as prosocial behaviour, meaning it may increase the welfare of another animal -- feeling better via the social attention and caring, or via substances in the saliva-insect mix that may be soothing or anti-inflammatory. There are examples of chimpanzees adopting and rescuing other chimpanzees, which may involve empathy.

We have regularly observed both species interacting peacefully in foraging trees. Our colleagues from Congo even witnessed playful interactions between the two great ape species.