Interactive effects of artificial light at night and anthropogenic noise on biological responses across taxa: a meta-analysis

Artificial light at night (ALAN) and anthropogenic noise are pervasive features of urbanisation and increasing components of global environmental change. Yet, their combined effects on biodiversity remain poorly understood due to the predominance of single-stressor approaches. Here, we conducted a factorial meta-analysis to quantify the interactive effects of ALAN and noise across taxa and biological responses. To our knowledge, this is the first quantitative synthesis to assess the interactive effects of these two widespread sensory pollutants on wildlife. We identified 30 articles explicitly testing these interactions, of which 16 contributed 151 effect sizes to the meta-analyses, primarily from birds, amphibians and insects, and encompassing four main outcome categories: behaviour, communication, physiology, and reproduction. We found evidence for non-additive interactions between ALAN and noise, with predominantly synergistic effects in amphibians, where combined exposure amplified negative responses, but antagonistic effects in insects, where the impacts of the two stressors were mitigated when combined. These contrasting patterns suggest that responses to multisensory pollution may vary substantially among taxa. Our results highlight the need to integrate multiple sensory stressors in ecological research, emphasizing the need for factorial designs and mechanistic investigations of neurosensory and neuroendocrine pathways. By demonstrating that interaction effects emerge even from sparse data, this study underscores the necessity of moving beyond additive assumptions to improve biodiversity impact assessments and conservation decision-making in increasingly multi-stressor environments.