The western barn own is a protected raptor under threat and used to be present on the mountain of Montjuïc. Its population has diminished significantly all around the territory in recent decades.

The reintroduction project for this species aims to strengthen the city’s biodiversity as part of the Barcelona Nature Plan and the Climate Plan, which have the goal of conserving biodiversity from solutions based on nature and scientific knowledge. Specifically, the species will help towards the natural control of rodent populations.

The releases are carried out at Montjuïc Castle, an 18^th century fortification with a multitude of open spaces and corners where the bird can hide during the day and hunt rodents at night. There are more spaces in the area around the castle that offer ideal habitats, for instance, the Jardí Botànic, the Jardins de Mossèn Cinto Verdaguer, the Jardins de Joan Brossa and the Viver de Tres Pins.

The project includes scientific follow-up through monitoring with infra-red cameras, with two owls also fitted with GPS devices to gauge their movements once they fly freely. Public awareness activities are also being considered.

The initiative is a collaboration between Barcelona City Council, the Government of Catalonia and Galanthus, with the Barcelona Public Health Agency (ASPB) and the Fundació Anticimex.