Habitat selection drives dietary specialisation inSorex minutus

To meet their demand for food, Eurasian pygmy shrews ( Sorex minutus ) require large territories, normally in fields, woodlands, and meadows. Their high metabolism and food requirement often leads to high mortality during winter. However, evidence of shrews in the roof voids of residential buildings has recently been observed, contrary to ecological expectations. Here, five faecal samples collected from different locations were studied by metagenomic analysis to gain information about the shrew’s diets and environments. Two of the samples were collected from novel indoor locations, while the other three were from outdoors in ‘traditional’ habitats. Distinct differences were observed between the diets of the two populations, suggesting a commensal niche expansion has occurred in S. minutus. We found that S. minutus exploit man-made spaces for foraging, potentially at the cost of a greater parasite burden.