Butterflies are, along with swallows, one of the most loved and awaited faunistic groups every year: they represent, without any doubt, the arrival of spring and summer. In addition, their bright colours and beautiful morphology arouse widespread interest, especially among children and nature lovers.
Moreover, it is a well-know fact in ecology that diurnal butterflies are excellent bio-indicators of changes in habitats and ecosystems; consequently, they are the most studied taxon in Europe as an indicator of climate change.
In Barcelona and Madrid, a project called Urban Butterfly Monitoring Scheme (UBMS) has been carried out since 2018. It consists in monitoring butterflies in the parks and gardens of both cities in Spain and, since 2021, it has been implemented in Sabadell, another Catalan city, too. What is remarkable is that citizen volunteers carry out transects and identify the species, working in a network and sharing the obtained data. This is done through a website managed by a research team and a group of experts to help the volunteers, who can share their data and observations. This citizen science project is linked to the European Butterfly Monitoring Scheme (BMS).