International audienceThe nocturnal environment emerged as a concept following the reclassification of “artificial light at night” as light pollution. It aims to define the human and non-human systems functionally associated with darkness. Unlike the notion of light pollution, it requires us to think about the multiple issues of both artificial light and darkness together. By placing it within the analytical framework of socio-ecological systems, we make the nocturnal environment a research object in its own right, one which is suitable for building an interdisciplinary approach between natural sciences and human and social sciences. We test this relational object in the real world on the island of Reunion, working with the Réunion National...