Res Nullius, Port de Barcelona, Catalunya, 2019

Res Nullius is a collaboration between the Association Barcelona Gat i Gos and the Barcelona Port Authority aimed at managing and protecting feral cat colonies in the Llobregat Delta area. Feral cats, neither domestic nor wild, play a crucial role in urban ecosystems yet often suffer due to their classification as res nullius, a legal status indicating unclaimed ownership akin to ancient Roman law. This designation has paved the way for mass extermination rather than recognition of their rights and ecological importance, despite their role in parasite control and disease prevention.

Barcelona Gat i Gos promotes the welfare of these cats through population management, advocating for their dignity and rights within human public spaces. The organization oversees local colonies, ensuring that cats receive sterilization, medical care, and shelter, with an emphasis on coexistence rather than eradication. The Port Authority contributes by providing facilities that support architectural design for the care of feral cats, utilizing concrete blocks to create isolated shelters that facilitate feeding and protection. This innovative approach fosters new interactions between species while highlighting the ecological and cultural value of feral cats in urban settings, counteracting cultural anthropocentrism and affirming their right to inhabit shared spaces.