To ensure the
long-term persistence and evolutionary potential of cranes,
accurate knowledge of the spatial distribution of genetic
variation and its underlying causes are necessary. We
assessed their genetic structure using 12 polymorphic
microsatellite loci and inferred the mechanisms shaping the
observed structure. Among the three regional groups in
Hokkaido, we found generally low pairwiseFSTvalues and
no significant differences in genetic diversity, probably
because of the population expansion in the recent past. In
contrast, spatial autocorrelation analysis revealed a significant positive kinship at the short distance (0–15 km) and
negative kinship at the long distance (155–205 km),
showing a pattern of isolation by distance. The presence of
isolation by distance on a small spatial scale despite the
species’ strong flight ability is probably explained by the
recolonization process and restricted dispersal due to natal
philopatry in a non-equilibrium condition.