Barn owls making a return to Barcelona 

Although once common on Barcelona's Montjuïc mountain and around Catalonia, owls have been declared a vulnerable species in the region and have been disappearing over recent decades. A project by the city council, Catalan government, and the Galanthus conservation organization now aims to reintroduce the nocturnal birds of prey to Montjuïc. 

In June, five barn owl chicks were released at Montjuïc Castle. Bred through the captive breeding program at the government's Vallcalent Wild Fauna Center, the chicks were fed chicken and mouse chicks for 71 days. This method of caring for raptors, called the "hacking" technique, was also used for the successful reintroduction of the peregrine falcon in Barcelona. 

The 18-century fortification of Montjuïc Castle was chosen for its open spaces and corners that would allow the owls to hide during the day and hunt rodents at night. The gardens surrounding the castle were also identified as ideal habitats. 

The owl chicks left the nest at the end of August. To monitor them, caretakers used infrared cameras and installed GPS devices on two of the specimens. 

Once the success of the first release is ensured, a second release from the same nest box is planned. 

Owls can work as a natural alternative to rodenticides, as mice are part of their diet. The owl initiative aims to increase Barcelona's biodiversity and control rodent populations without harming other fauna.