The Citizen Observatory of Urban Butterflies (uBMS) is a collaborative network of volunteers who join forces to obtain data on the populations of butterflies in the cities of Barcelona and Madrid. In this way, relevant data is obtained to evaluate and monitor the status and trends of the urban biodiversity in these cities. This information provides us with an understanding of which characteristics of the cities promote biodiversity and which limit it, which allows us to recommend best urban greening strategies to favour biodiversity.

The uBMS belongs to the European network of Butterfly Monitoring Programs (eBMS) in force in more than 25 countries, focused on social and applied ecological solutions for nature conservation.