| The alpine swift belongs to the same family as the common swift -with long, thin curved wings- but is larger and has a clean white throat and belly. It is a summer species, arriving at the end of March, By the end of October all alpine swifts have left the city on route to Africa, their winter quarters. They feed basically on flying invertebrates, and they build their nests, as does the common swift, using their saliva and other fine materials. The nest is constructed in cliffs and very high buildings. Barcelona has the largest number of swifts in Catalonia. It is calculated that there are between 6,000 and 10,000 pairs in the metropolitan area of Barcelona, representing 60% of the Catalan population. Montjuïc Castle and Camp Nou are two of its principal breeding sites. The restoration of buildings home to colonies of alpine swifts is possibly one of the principal negative impacts on the species. |
