As in many cities, one of the ecological ravages that is ongoing in Brussels is the loss of its wildlife and their habitats. Among them, common swifts (Apus apus) are migrating and insectivorous birds that come back each summer to the same cavity, like eaves, ventilation holes, cracks, or putlog holes. In the last decades, new construction and renovation led to the destruction of these breeding sites, to the point that Brussels’s swifts have plummeted by half. This loss prompted a handful of swift enthusiasts to convert specific architectural interfaces into suitable cavities for the birds, sometimes with the support of the local authorities. I look at these nest boxes as multiple technologies, each of them retrieving from past artefacts and experiences that carry distinct matters of concerns for swifts, their caretakers, and their co-becoming. Nest boxes are firstly reproductive technologies developed by the birds since ancient times, enacted as such at their own biosocial rhythm, and relying on architecture from specific epochs. Second, following ornithologists’ experiments from mid-20e century, city dwellers convert these nest boxes into technologies of vision, to watch over swifts’ daily life. Then, certain nest boxes draw inspiration from medieval towers built as breeding technologies, at a time when nestlings were appreciated as delicacies. Nest boxes as multiple technologies assemble attempts to recuperate what can still be salvaged from different past times. I reflect on the path that such recuperations open for interspecific alliances, that is neither a restoration of authentic ‘nature’, nor a harmonious reconciliation.
d'Hoop et al. (2024) studied this question.