Conservation genetics and ecology of the hazel dormouse

Combe, Fraser (2018) Conservation genetics and ecology of the hazel dormouse. Doctoral thesis (PhD), Manchester Metropolitan University.

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Abstract

Woodland species face a challenging future because of human activity and global climate change, as such it is vital to understand the ecology of species that inhabit these habitats in order to conduct effective conservation management. I describe the phylogeographic structure of the hazel dormouse within the UK, to identify post-glacial dispersal routes and to describe population units for conservation. I provide evidence for a single post-glacial colonization coincident with the start of the Holocene period, 7.5-11 Kya. I also demonstrate the utility of novel occupancy modelling techniques to determine dormouse presence with high probability of detection. I provide optimal survey guidelines for ecological practitioners to conduct rigorous statistically significant surveys. This species is known to be susceptible to habitat loss and fragmentation limiting dispersal and functional connectivity. I use a landscape genetics approach to characterize the genetic structure of populations of dormice from seven regions around the UK to explicitly test for the role of landscape heterogeneity and barriers to dispersal. The results suggests build-up of genetic structure amongst islands of fragmented habitat that is explained in part due to isolation-by-distance, and in part due to specific landscape features between different regions. The isolation-by-resistance analysis allows us to identify the landscape features, such as land cover, hedgerows and roads that facilitate or inhibit gene flow. Results suggest that dispersal in hazel dormice is strongly influenced by barriers in the landscape, with our main findings being that urban areas and roads are associated with decreased gene flow while habitat features such as hedgerows and forest cover are associated with increased gene flow. Finally, I investigated the effect of density dependence and climatic factors on the population demography of five marked hazel dormice populations in Europe (four in the UK and one in Lithuania). The results from the chapter have identified the environmental drivers of these population parameters on hibernating mammals whilst providing evidence that density dependence has the greatest effect on population dynamics in this species. The results provide information that variability in winter conditions can have serious consequences for individual fitness, decreasing the dormancy season and leading to an increased extinction risk in this species. I discuss the implications for hazel dormouse conservation in the UK, and make recommendations for conservation practitioners to ensure the future persistence of this species.