Conclusions

Analyses of multiple molecular markers with different means of inheritance has demonstrated contrasting patterns of recolonization for the pygmy shrew in continental Europe. Five major lineages were retrieved from mtDNA data, in accordance with Mascheretti et al. (2003). In contrast, four major lineages were retrieved from Y chromosome data. By using mtDNA alone, contact between French and Spanish refugia would not have been identified and this study has highlighted the importance of adopting a multiple marker approach in phylogeo-graphic studies.

The pygmy shrew is the oldest shrew found in Europe (based on fossil data; Rzebik-Kowalska 1998) and is relatively rare on the European mainland (often restricted to high altitudes) in comparison to other shrew species because of competition with species which occupy similar niches and as a result of habitat fragmentation. The genetic lineages described in this study diverged several glacial cycles ago and therefore each has an ancient evolutionary history (Jaarola and Searle 2004). Some of these lineages are relatively rare on the European continent in comparison to others. For example, the Northern lineage is spread throughout Northern and Eastern parts of Europe while the other lineages are relatively restricted in their distribution, often confined to the Southern refugial regions. Fully identifying refugial locations and protecting reservoirs of genetic diversity is vital for the long-term persistence and conservation of pygmy shrew populations (Bhagwat and Willis 2008).

Acknowledgments We thank Damien and Anne McDevitt, Jacqueline Fox, and Marine Pascal for field assistance in France. Thanks to Vitaly Volobouev and Michel Pascal for providing the appropriate licences for trapping and Alain Butet, Anne Tresset, and Carlos Nores for trapping advice. We particularly thank John O'Brien, James Carolan and everyone in Research Lab 4 (UCD) for technical assistance in the laboratory. We thank Don Stewart, John O'Brien, Rodrigo Vega, and Jerry Herman for their help and comments on the earlier drafts of the manuscript and Olaya Astudillo for help with figures. A.D. McDevitt was funded by the Irish Research Council for Science, Engineering and Technology (IRCSET) and a travel grant to France awarded by Enterprise Ireland. G. Yannic was supported by a grant from the Fondation Agassiz (Switzerland). J.B. Searle received field work funding from the Arts and Humanities Research Council (UK).

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