Research article
Introgression of mountain hare (Lepus timidus) mitochondrial DNA into wild brown hares (Lepus europaeus) in Denmark
1 Department of Ecology and Genetics, Institute of Biological Sciences, University of Aarhus, Ny Munkegade, building 1540, DK-8000 Aarhus C, Denmark
2 National Environmental Research Institute, Dept. of Wildlife Ecology and Biodiversity, Grenaavej 14, DK-8410 Ronde, Denmark
3 BiRC – Bioinformatics Research Center, University of Aarhus, H.-Guldbergs Gade 10, Building 1090, DK-8000 Aarhus C, Denmark
BMC Ecology 2006, 6:17 doi:10.1186/1472-6785-6-17
Published: 15 November 2006Abstract
Background
In Europe the mountain hare (Lepus timidus) exists in Great Britain, Norway, Sweden, Finland, parts of the Alps and in Eastern Europe, but not in Denmark. Interspecific hybridization has been demonstrated between native Swedish mountain hares and introduced brown hares (Lepus europaeus). During the data collection in a study concerning Danish brown hares we identified 16 hares with a single very divergent haplotype.
Results
Phylogenetic analysis shows that the divergent Danish haplotype is most closely related to the Swedish mountain hare. The frequency of Lepus timidus mtDNA haplotype in the Eastern Danish hare populations is estimated to 6%.
Conclusion
In contrast to what is known, the Danish hare populations are not pure L. europaeus populations but include introgressed brown hares with Swedish L. timidus mtDNA. The most probable explanation of this is natural migration or translocation of introgressed brown hares from Sweden. The impurity of hare populations has implications for conservation and population genetics.



