In 2025, the Community of Madrid reintroduced 1,332 swift chicks in the capital, after being rescued and rehabilitated at the Wildlife Recovery Center (CRAS) Félix Rodríguez de la Fuente.
The swift is an extraordinary bird: it weighs barely between 30 and 50 grams, but covers thousands of kilometers in its annual migration from sub-Saharan Africa to Europe. It lives practically in the air — it sleeps, feeds, and even mates in flight — and only touches the ground to nest.
The problem of high temperatures
Every spring and summer, heat waves affect the nests on building rooftops. The chicks, still without enough feathers to regulate their temperature or the ability to fly, fall to the ground. In 2025, CRAS recorded 1,547 swift admissions, mostly in June and July.
The center’s technicians perform a titanic task: constant feeding, hydration, veterinary control, and individualized monitoring. But keeping them alive is not enough: they need to learn social behaviors and flying skills to survive in the wild.
The fostering technique
This is where fostering comes into play, an innovative method that revolutionized the reintroduction of swifts in urban environments. It involves identifying breeding pairs in natural colonies and placing the rescued chicks alongside their own.
The result is surprising: the adoptive parents accept the new chicks and feed them as their own, while the adoptive siblings teach them essential socialization and flying behaviors.
The success is overwhelming: 97.37% of the chicks survived, an unthinkable figure with conventional methods.
A joint effort
The reintroductions were carried out in official buildings of the Ministry of Economy, Trade and Business, Industry and Tourism, and Science, Innovation and Universities, in collaboration between the Community of Madrid and the national Administration.
Each swift that now soars through the Madrid sky is the result of a collective effort: technicians who fed them night after night, experts who located the appropriate nests, and adult birds who, unknowingly, became adoptive parents.
Ecological and cultural value
The mixed colonies of common swift and pallid swift in areas like Cuzco are enclaves of great value for urban biodiversity. Their presence marks the pulse of spring and summer in the city, and their absence announces the end of the warm season.
Moreover, swifts play a vital ecological role: they control insect populations and contribute to the balance of urban ecosystems.
The fostering program in Madrid demonstrates that science and cooperation can save thousands of lives and strengthen urban biodiversity. Swifts, creatures of the pure air, once again fill the skies thanks to a second chance. Nature, when given support, responds with resilience and beauty.
