Dutch house sparrow (Passer domesticus) densities dropped by nearly 50% since the early 1980s, and similar collapses in population sizes have been reported across Europe. Whether, and to what extent, such relatively recent demographic changes are accompanied by concomitant shifts in the genetic population structure of this species needs further investigation. Therefore, we here explore temporal shifts in genetic diversity, genetic structure and effective sizes of seven Dutch house sparrow populations. To allow the most powerful statistical inference, historical populations were resampled at identical locations and each individual bird was genotyped using nine polymorphic microsatellites. Although the demographic history was not reflected by a reduction in genetic diversity, levels of genetic differentiation increased over time, and the original, panmictic population (inferred from the museum samples) diverged into two distinct genetic clusters. Reductions in census size were supported by a substantial ... : House sparrows dataGenetic data and GPS coordinates of 7 Dutch house sparrow populations.Pre-decline samples and post-decline samples are presented in the first and second excel sheet respectively. The first line of each sheet corresponds to: the number of microsatellite loci, the number of individuals, the number of populations and the number of sampled individuals in each populations. Then, "sample" is the individual label and "Pop" is the name of the population. This is followed by the 9 microsatellite loci. In the 2 last columns are reported the GPS coordinates for each individual. ...