Data from: Rapid colonisation of synanthropic stone martens in a highly urbanised region: Insights from temporal and spatial analysis

Medium-sized carnivores, including the synanthropic stone marten (Martes
foina Erxleben, 1777), have shown remarkable adaptability to urbanized and
fragmented landscapes, facilitating their spread across mainland Europe.
This study investigates the recolonisation of a highly urbanised region by
stone martens within two decades, examining spatial and temporal
genome-wide data (using genotyping by sequencing) to reveal colonisation
dynamics, sources, and barriers influencing their expansion. Using
genotypes from 5,536 SNPs across 376 stone martens collected between 1995
and 2013, our findings indicate that stone martens successfully expanded
through urban environments, yet dispersal was neither entirely random nor
strictly distance-dependent. The initial southeastern stronghold (E1)
showed the lowest genetic diversity and limited spatial expansion, while
other population sources contributed to recolonisation, highlighting a
complex, multi-source expansion. Gene flow in the early stages was largely
confined to E1, progressing northward and eventually enabling exchange
with a second eastern lineage (E2). Meanwhile, the western lineage
displayed higher connectivity, occasionally crossing barriers like
motorways. Motorways, however, significantly shaped recolonization
patterns, reducing gene flow, while other elements such as built-up areas,
secondary roads or waterways showed an additional though very small
effect. Over the study period, genetic patch size increased, indicating
longer dispersal distances. Gene flow strengthened within both eastern (E1
and E2) and western populations. Still, the western population diverged in
two subclusters (W1 and W2) of which one became more differentiated. This
suggests limited genetic homogenization in the near future. This study
provides insights into the genetic and ecological dynamics of carnivore
recolonization in highly fragmented landscapes.