Vocal “duel” between groups of howler monkeys: better have the final say!

This study examined 46 encounters between groups of black howler monkeys (Alouatta pigra) in Palenque, Mexico, to understand how their vocalizations affect contest outcomes. Groups were more likely to prevail when adult males ended bouts in coordination, when females joined in, when sequences were longer, and when they began with roars call type. In contrast, who initiated the howling bout, the number of adults present had no effect. The results show that these “vocal duels” are structured displays signaling group cohesion and motivation.

本研究针对墨西哥帕伦克地区的46次黑吼猴（Alouatta pigra）群体间遭遇事件开展观测分析，旨在探究其鸣叫声对群体争斗结果的影响。当成年雄性个体协同结束争斗回合、雌性群体参与其中、鸣唱序列更长，且初始鸣唱类型为咆哮叫声时，相关群体更易在争斗中占据优势。与之相反，嚎叫回合的发起者以及在场成年个体的数量，均未对争斗结果产生显著影响。研究结果表明，这类“鸣唱决斗”属于传递群体凝聚力与战斗动机的结构化展示行为。