The study took place in the city of Leipzig, Germany (51°20′ N, 12°25′ E), which is unique for the riparian forest crossing the centre on north-south direction. Thus, natural and semi-natural habitats occur in close vicinity to non-natural habitats of the city. Out of the semi-natural habitats (urban forest, parks, P) and non-natural habitats of the city (C), we selected ten study sites spanning a gradient of noise and light intensity (Fig. 1 & Fig. S1). The inner city centre itself is a traffic-calmed pedestrian zone and thus exceptionally quiet, so it deviates from the pattern of an increasing noise and light level from semi-natural to non-natural habitats (C4, Fig. S1). The inner city centre is well defined by a noisy and busy ring road with adjacent tiny parks (C1) and green spaces (C2). A derelict area used as parking lot marks the southern edge of the city (C3). To the southwest follow a series of public parks (P2– P6) of different sizes with pathways and lawns and a great variety of evergreen and deciduous bushes and trees. A dense urban forest (P1) links those parks to the riparian forest. The successive transition from semi-natural to urban structures stretches over only 3 km representing a steep urban gradient. The whole study site covers 215 ha and is surrounded by residential housing.