On the evolution of baboon greeting rituals

Abstract

To balance the trade-offs of male co-residence, males living in multi-male groups may exchange ritualized greetings. Although these non-aggressive signals are widespread in the animal kingdom, the repertoire described in the genus Papio is exceptional, involving potentially harmful behaviours such as genital fondling. Such greetings are among the most striking male baboon social interactions, yet their function remains disputed. Drawing on the comprehensive analysis from our own research on wild Guinea baboons, combined with a survey of the literature into other baboon species, we review the form and function of male-male ritualized greetings and their relation to the various social systems present in this genus. These ritualized signals differ between species in their occurrence, form, and function. While ritualized greetings are rare in species with the most intense contest competition, the complexity of and risk involved in greeting rituals increase with the degree of male-male tolerance and cooperation. The variety of societies found in this genus, combined with its role as a model for human socioecological evolution, sheds light on the evolution of ritualized behaviour in non-human primates and rituals in humans.

Increased female competition for males with enhanced foraging skills in Guinea baboons

“…In addition to our main predictors, we included precipitation as a fixed effect in all models. Precipitation was measured as mm of rain per day (Dal Pesco & Fischer, 2023). It was included to account for the tendency of the baboons, both zoo housed and wild, to form furry huddles whenever it rained -significantly altering interaction patterns.…”