Species studied
Birds and butterflies are recognized biodiversity indicators both in natural and human-modified landscapes. Their use as bioindicators comes from the variability within species and their ability to respond fast to environmental changes; including agricultural intensification and land abandonment (12 ,13 ,14 ,51 ). We obtained butterfly data from the Catalan Butterfly Monitoring Scheme (CBMS;http://www.catalanbms.org/) running for the last 25 years (thus accounting for variable data length). The survey consists of a network of sites where visual counts of adult butterflies along transects are undertaken by volunteers. In each transect butterflies’ surveys are done weekly during the flight period of imagos (March-September) along lineal transects of ca. 700-2500m length (mean and median length = 1715 and 2010m respectively, wide 5m). Each transect is divided in smaller sections per dominant habitat type, leading to 6 to 14 sections per transect. Number of individuals (i.e. observations) are then recorded per species in each section, and then summarized per transect. We used 91 transects for the BMR (2009). In the case of birds, we obtained data from the Catalan monitoring scheme of common birds (SOCC;www.giraffa.co/ico-catalan-ornithological-institute/). Transects consist on a 3-km track with six sections of 600m. Along these, the observers record bird observations and auditions, and then summarize data per transect. Two yearly censuses are performed for breeding species (April-May and May-June), and two for wintering species (December and January). We used 23 transects for the BMR (2009).