From streetlight to starlight: How light pollution disrupts insect orientation and alters habitat connectivity

The widespread use of artificial lighting has drastically changed night skies across the globe, creating a specific threat to nocturnal species: light pollution. Recently, light pollution has been identified as one driver of insect decline. Among nocturnal insects, moths are particularly important as they serve as both key pollinators and food source, providing essential ecosystem functions. To mitigate the effects of light pollution, a comprehensive understanding of moth orientation is essential, including their response to natural and artificial light as well as their interplay. To date the available data is extremely limited, primarily due to the challenging conditions of night-time research and the lack of methods for collecting behavioural data in the field.LIGHTSTAR will set a paradigm-shift beyond classical field and laboratory experiments by combining large-scale field experiments across a light pollution gradient with targeted manipulations of streetlights, moonlight, and polarized light. This approach will allow an in-depth investigation on the orientation performance of moths in dependence on the light environment. We will develop a drone-based 3D tracking system to obtain behavioural data of unprecedented spatial and temporal resolution. Incorporating these novel 3D data into our advanced simulation tools will fundamentally broaden our understanding of habitat fragmentation caused by streetlights and will allow a new dimension of assessing habitat connectivity.The data collected will, for the first time, provide a holistic understanding of the impact of light pollution on the orientation of nocturnal insects. Our discoveries will be highly valuable for developing strategies to mitigate their decline and promote insect-friendly lighting solutions that can reduce the risk of species extinctions and maintain connectivity of habitats. Moreover, our new tracking system will unlock new realms for all research on movement and behavioural ecology of insects.