Preston Elizabeth F R, Thompson Faye J, Kyabulima Solomon, Croft Darren P, Cant Michael A
Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Exeter UK.
Banded Mongoose Research Project Queen Elizabeth National Park Uganda.
Ecol Evol. 2021 Dec 20;11(24):18662-18675. doi: 10.1002/ece3.8475. eCollection 2021 Dec.
Intergroup conflict is widespread in nature and is proposed to have strong impacts on the evolution of social behavior. The conflict-cohesion hypothesis predicts that exposure to intergroup conflict should lead to increased social cohesion to improve group success or resilience in future conflicts. There is evidence to support this prediction from studies of affiliative responses to outgroup threats in some animal societies. However, most of these studies have focused on behavioral changes over short time periods (minutes and hours after exposure to an outgroup), and hence very little is known about the dynamics and durability of responses to intergroup conflict over the longer term. We investigated this question by simulating intergroup encounters in wild banded mongooses () and measuring social behavior before, during, and after these encounters over a 5-day period. We also ran control trials with non-threatening stimuli. Banded mongooses reacted immediately to intrusion stimuli by vocalizing, grouping together, and advancing on the stimulus. In the first 5 min after simulated intrusions, we saw an elevation in grooming levels, but in the hour after exposure grooming rates declined sharply, contrary to our expectation. In the two subsequent days, grooming rates remained at this depressed rate. In control trials, the initial increase in grooming was not seen, but grooming declined compared to the longer-term time periods. Grooming changed across time, but not in the same pattern as during intrusions, suggesting that intrusions had an impact above and beyond that of the experimental setup. The dynamics of grooming responses were short lived and more complex than we initially expected. We suggest this unexpected result may be linked to the frequency of aggressive intergroup encounters in this system. As control and experimental trials were run at different times of year, future work would be needed to confirm that these relative patterns are replicable. Our results indicate short-lived impacts of outgroup threat on measures of social cohesion in this species, but cannot confirm longer-term changes.
群体间冲突在自然界中广泛存在，并且被认为对社会行为的进化有强烈影响。冲突 - 凝聚假说预测，接触群体间冲突应该会导致社会凝聚力增强，以提高群体在未来冲突中的成功率或恢复力。在一些动物社会中，对外群体威胁的亲和反应研究有证据支持这一预测。然而，这些研究大多集中在短时间内（接触外群体后的几分钟和几小时）的行为变化，因此对于长期内对群体间冲突反应的动态变化和持续性知之甚少。我们通过模拟野生带状猫鼬（）的群体间相遇，并在为期5天的时间里测量相遇前、相遇期间和相遇后的社会行为来研究这个问题。我们还进行了非威胁性刺激的对照试验。带状猫鼬通过发声、聚集在一起并向刺激源前进，对入侵刺激立即做出反应。在模拟入侵后的前5分钟，我们观察到梳理行为水平有所提高，但在接触后的一小时内，梳理率急剧下降，这与我们的预期相反。在随后的两天里，梳理率一直维持在这个较低水平。在对照试验中，没有观察到梳理行为的初始增加，但与长期时间段相比，梳理行为有所下降。梳理行为随时间变化，但与入侵期间的模式不同，这表明入侵的影响超出了实验设置本身。梳理反应的动态变化是短暂的，比我们最初预期的更为复杂。我们认为这个意外结果可能与该系统中群体间攻击性相遇的频率有关。由于对照试验和实验试验在一年中的不同时间进行，未来需要开展工作来确认这些相对模式是否可重复。我们的结果表明外群体威胁对该物种社会凝聚力指标的影响是短暂的，但无法证实长期变化。
