r/primatology

In 1993, scientists conducted an experiment in which they housed young rhesus macaques with slightly older stump-tail macaques. Rhesus are known for being pretty aggressive, whereas stump-tails are relatively chill -- they ignore minor slights & reconcile after conflicts.

The experiment tested whether the stumpies’ pacifism would rub off on the rhesus monkeys.

At first, the 2 species avoided each other, but over time that self-segregation diminished. By the end of 5 months, all of the monkeys were grooming each other & sleeping in a single huddle. 

Moreover, the rhesus macaques adopted their older cousins’  friendly nature & reconciled after conflicts as often as the stump-tails. The rhesus didn't exactly copy other behaviors; they continued acting like rhesus, just with a friendly disposition. 

(See Frans de Waal, Good Natured, 1996, pp 179-180.)

Been meaning to share this — chimp trekking in Kibale Forest (Uganda) doesn't get talked about nearly as much as gorilla trekking in Bwindi, but it's honestly just as incredible in a different way.

Kibale has one of the highest primate densities in Africa. You're tracking through the forest with guides, and the chimps are just... loud. Calls echoing through the canopy, families moving fast through the trees, way more chaotic and dynamic than the calmer gorilla encounters. It feels more "wild" in some ways.

A few practical notes if anyone's considering it:

Permits are far cheaper than gorilla permits (~$250 vs $700+ for gorillas)

Best paired with a Bwindi gorilla trek if you're already in western Uganda

Morning treks tend to have better sighting odds since chimps are more active early

Happy to answer questions if anyone's planning a Uganda trip — I work with a ground operator out there (Rwatata Safaris) and can point people in the right direction if useful.