DOI: 10.5061/dryad.pk0p2ngnq
title: Microsatellite data of Southern Dunlin breeding across the Baltic

description: The stored data were used in a study by Rönkä et al. (2021). See full
 citation in Usage notes. Here is the abstract of Rönkä et al. (2021).
 Background: Populations living in fragmented habitats may suffer from loss
 of genetic variation and reduced between-patch dispersal, which are
 processes that can result in genetic differentiation. This occurs
 frequently in species with reduced mobility, whereas genetic
 differentiation is less common among mobile species such as migratory
 birds. The high dispersal capacity in the latter species usually allows
 for gene flow even in fragmented landscapes. However, strongly philopatric
 behaviour can reinforce relative isolation and the degree of genetic
 differentiation. The Southern Dunlin (Calidris alpina schinzii) is a
 philopatric, long-distance migratory shorebird and shows reduced dispersal
 between isolated breeding patches. The endangered population of the
 Southern Dunlin breeding at the Baltic Sea has suffered from habitat
 deterioration and fragmentation of coastal meadows. We sampled DNA across
 the entire population and used 12 polymorphic microsatellite loci to
 examine whether the environmental changes have resulted in genetic
 structuring and loss of variation. Results: We found a pattern of
 isolation-by-distance across the whole Baltic population and genetic
 differentiation between local populations, even within the southern
 Baltic. Observed heterozygosity was lower than expected throughout the
 range and internal relatedness values were positive indicating inbreeding.
 Conclusions: Our results provide long-term, empirical evidence for the
 theoretically expected links between habitat fragmentation, population
 subdivision, and gene flow. They also demonstrate a rare case of genetic
 differentiation between populations of a long-distance migratory species.
 The Baltic Southern Dunlin differs from many related shorebird species
 that show near panmixia, reflecting its philopatric life history and the
 reduced connectivity of its breeding patches. The results have important
 implications as they suggest that reduced connectivity of breeding
 habitats can threaten even long-distance migrants if they show strong
 philopatry during breeding. The Baltic Southern Dunlin warrants urgent
 conservation efforts that increase functional connectivity and gene flow
 between breeding areas.
description: The data include samples from 8 different breeding populations of
 the southern dunlin across the Baltic Sea (1. Finland, Bothnian Bay; 2.
 Finland, Pori; 3. Finland, Jurmo; 4. Estonia; 5. Denmark; 6. Western
 Sweden; 7. Eastern Sweden and 8. Southern Sweden). Samples were collected
 during the breeding season during years (1997–2016). DNA was extracted and
 12 microsatellites were amplified. These markers included (Ruff1, Ruff6,
 Pgt83, Cme1, Cme2, Cme6, Calp2, CAS009877, CAS011379, CAS012162,
 CAS023374, CAS026519).
description: The file includes allele data for 12 microsatellites (columns;
 two alleles per locus) for each samples individual (row). The first column
 indicates individual ID and sampled population. Missing values are blank
 cells. Rönkä N, Pakanen VM, Pauliny A, Thomson RL,
 Nuotio K, Pehlak H, Thorup O, Lehikoinen P, Rönkä A, Blomqvist D, Koivula
 K, Kvist L (2021) Genetic differentiation in an endangered and strongly
 philopatric, migrant shorebird.  <i>BMC Ecol Evo</i>
 <b>21, </b>125.
 https://doi.org/10.1186/s12862-021-01855-0