Sociability Under Anthropogenic Change: From Individual Behaviour to Population-Level Consequences.

Animal responses to anthropogenic environmental change depend not only on individual phenotypes, but also on how individuals associate with one another. Sociability-the tendency to seek or tolerate association with conspecifics-links individual behaviour to social organisation and population processes. In this review, we synthesise empirical and theoretical work to examine sociability as a mechanistic axis connecting individual behaviour, social networks and population processes under anthropogenic change. We distinguish sociability from broader concepts such as sociality and social complexity, and integrate evidence across taxa and levels of biological organisation. We examine how sociability mediates animal responses to habitat modification, climate change, pollution, disturbance, provisioning and non-random mortality, and how these responses scale from social interactions to networks and broader social organisation. Across systems, sociability can either buffer or amplify the effects of anthropogenic change depending on how environmental disturbance reshapes the costs and benefits of association. By altering energetic constraints, predation risk, disease exposure, and access to information and resources, anthropogenic change can shift when, how, and for whom social associations are beneficial. Social ties may reduce short-term stress and uncertainty, but they may also intensify competition, pathogen transmission, or social destabilisation. These outcomes are strongly context dependent, varying with species ecology, social system organisation, temporal scale and broader disturbance regimes. By positioning sociability as an important pathway through which anthropogenic change can scale from individuals to populations, we identify priorities for future research, particularly long-term individual-based studies that disentangle plasticity and consistency in social behaviour, and test how anthropogenic change shapes selection on social traits.