Swallows are highly associated with man-made constructions, to the extent that they almost depend upon them for their very survival. The transformation and, in some cases, disappearance of the rural world, on the one hand, and the demolition of traditional farm buildings and homes, on the other, have made it more and more difficult for swallows and martins to find places in which to nest and material to build them. Nests are also sometimes destroyed as the result of reforming of building facades. In Barcelona city all of these above causes has led to the practical disappearance both of the common swallow (Hirundo rustica) and, to a lesser extent, the house martin (Delichon urbicum). Girona, because of its size physical characteristics, still conserves a good population of swallows and martins.
This project includes a census, an environmental awareness campaign, the resolution of conflicts with owners and the installation of nest boxes. With the data collected in the field studies an SIG has been created in order to query data and monitor populations.
In the city of Barcelona , the study has been carried out by Galanthus and Thalassia Estudis Ambientals S.L., and was made possible thanks to financing from the City Council and a grant from the Caixa Tarragona. The participation process has involved schools belonging to the Agenda 21 network, and students doing practice work with the Agricultural School of Amposta.
In Girona the study of the population of swallows and martins has been financed fully by the City Council and carried out by Galanthus.