Urban environments represent a theatre for life history evolution.
Species able to survive in cities can adapt to the local and often
divergent environmental conditions compared to rural or natural
environments. Dispersal determines establishment, gene flow, and thus
the potential for local adaptation. Since habitats in urban environments
are highly fragmented, and showing substantial turnover, contrasting
adaptive effects on dispersal are expected. Fragmentation selects
against dispersal while patch turn-over is expected to promote the
evolution of dispersal. We here show both processes to act in concert
when different scales are considered. Dispersal behaviour of juvenile,
lab-reared garden spiders from two mid-sized European cities were tested
under standardized conditions. While long-distance dispersal showed to
be overall rare, short-distance dispersal strategies increased with
urbanization at small scales, but declined when urbanization was
quantified at large scales. We discuss the putative drivers behind these
differences in natal dispersal and highlight its importance for urban
evolution and ecology.