A Map over Sweden with systematically placed bird monitoring squares throughout the country, used by the Swedish Bird Survey. The two regions featured in this study are shown, with monitoring squares visited portrayed in red. The squares are 2×2 km wide, indicate location, and not shown to scale B Example map of a bird monitoring square: site Kongaö in Scania, Sweden, indicated as a red, 2×2 km square. Butterfly transects followed the periphery of bird monitoring squares (N = 8 sites) as closely as possible for as long as weather conditions and time of day permitted (Pettersson et al. 2011). Lantmäteriet, I2014/00579.