The Invasion of the Greater White-Toothed Shrew, and the Potential Disruption of the Relationship Between Parasites and the Native Pygmy Shrew in Ireland
SPARC 2022 Poster Number 6
The pygmy shrew (Sorex minutus) was the only shrew species inhabiting Ireland, until 2007 when the invasion of the greater white-toothed shrew (Crocidura russula) was first recorded. Since its discovery in Ireland, the range of the greater white-toothed shrew has been expanding yearly at a rate of approximately 5Km. This is a great risk to the pygmy shrew as the two species are unable to coexist, which results in the native shrew being absent from areas that the invasive species is present. As well as displacing local populations, invasive species can have a large impact on the native host-parasite relationships, either in an amplification or dilution effect, with the possibility of introducing novel parasites. This study aims to explore how the invasion of the greater white-toothed shrew has affected such dynamics between the pygmy shrew and their associated blood and gut parasites. Samples, of both species, have been previously collected across radial transects in Ireland during two different seasons, where their hearts were harvested and DNA from the gut contents had been extracted. Further analyses of these samples aim to identify any effect that the invasion may have had on the prevalence of associated parasites. Consequently, the results from this study will provide complementary data on how the greater white-toothed shrew has affected, and potentially become detrimental to, the pygmy shrew population in Ireland, which is valuable information when designing appropriate conservation measures.