Data from: Wild birds respond to flockmate loss by increasing their social network associations to others

Understanding the consequences of losing individuals from wild populations is a current and pressing issue, yet how such loss influences the social behaviour of the remaining animals is largely unexplored. Through combining the automated tracking of winter flocks of over 500 wild great tits (Parus major) with removal experiments, we assessed how individuals’ social network positions responded to the loss of their social associates. We found that the extent of flockmate loss that individuals experienced correlated positively with subsequent increases in the number of their social associations, the average strength of their bonds, and their overall connectedness within the social network (defined as summed edge weights). Increased social connectivity was not driven by general disturbance or changes in foraging behavior, but by modifications to fine-scale social network connections in response to losing their associates. Therefore, the reduction in social connectedness expected by individual loss may be mitigated by increases in social associations between remaining individuals. Given that these findings demonstrate rapid adjustment of social network associations in response to the loss of previous social ties, future research should examine the generality of the compensatory adjustment of social relations in ways that maintain the structure of social organization.探明野生种群中个体丢失所引发的生态后果是当前亟待解决的热点问题，然而此类个体损失如何影响剩余个体的社会行为，目前尚未得到充分探究。本研究通过对500余只野生大山雀（Parus major）的冬季鸟群开展自动追踪与移除实验，量化评估了个体的社会网络位置如何响应其社交伙伴的丢失。研究结果显示，个体所经历的同群个体损失程度，与其后续社交关联数量、社会联结平均强度，以及其在社交网络中的整体连通性（定义为边权重之和）均呈显著正相关。进一步分析表明，社交连通性的提升并非由一般性扰动或觅食行为改变所驱动，而是源于个体在丢失社交伙伴后对精细尺度社会网络联结所做出的适应性调整。因此，个体丢失所预期的社会连通性损失，可通过剩余个体间社交关联的增加得到缓解。鉴于本研究揭示了个体在原有社交纽带丢失后可快速调整社交关联，未来研究应进一步探索维持社会组织结构的社会关系补偿性调整的普遍性。