Data from: Sneeze to leave: African wild dogs (Lycaon pictus) use variable quorum thresholds facilitated by sneezes in collective decisions.

In despotically driven animal societies, one or a few individuals tend to have a disproportionate influence on group decision-making and actions. However, global communication allows each group member to assess the relative strength of preferences for different options amongst their group-mates. Here, we investigate collective decisions by free-ranging African wild dog packs in Botswana. African wild dogs exhibit dominant-directed group living and take part in stereotyped social rallies: high energy greeting ceremonies that occur before collective movements. Not all rallies result in collective movements, for reasons that are not well understood. We show that the probability of rally success (i.e. group departure) is predicted by a minimum number of audible rapid nasal exhalations ('sneezes'), within the rally. Moreover, the number of sneezes needed for the group to depart (i.e. the quorum) was reduced whenever dominant individuals initiated rallies, suggesting that dominant participation increases the likelihood of a rally's success, but is not a prerequisite. As such, the 'will of the group' may override dominant preferences when the consensus of subordinates is sufficiently great. Our findings illustrate how specific behavioural mechanisms (here, sneezing) allow for negotiation (in effect, voting) that shapes decision-making in a wild, socially complex animal society.

在威权主导的动物社群中，往往有少数个体对群体决策与群体行为拥有不成比例的影响力。然而，群体全局信息交流使得每个成员能够评估同伴间对不同备选方案的偏好相对强弱。本研究针对博茨瓦纳境内的自由放养非洲野犬种群的集体决策展开调查。非洲野犬呈现出以优势个体为导向的群体生活模式，并会参与刻板化的社交集会——即集体行动前举行的高能量问候仪式。但并非所有集会都会促成集体行动，其背后的机制目前尚未得到充分阐释。研究表明，集会成功（即群体启程）的概率，可由集会过程中所需的最少可闻快速鼻息（即“喷嚏”）数量来预测。此外，当优势个体发起集会时，群体启程所需的喷嚏法定人数（quorum）会降低，这表明优势个体的参与能够提升集会成功的概率，但并非成功的必要条件。在此情况下，当下属群体的共识足够强烈时，“群体意志”或可凌驾于优势个体的偏好之上。本研究结果阐明了特定行为机制（此处为喷嚏行为）如何通过协商（本质上即为投票），在野生且社会结构复杂的动物社群中塑造群体决策。