Food Availability and the Diet of the Common Shrew, Sorex araneus, in Britain

(1) The relationship between seasonal food availability and the diet of Sorex araneus in scrub-grassland was investigated using pitfall traps and soil/vegetation core sampling for invertebrates and analysis of shrew faecal pellets. (2) A wide variety of prey was taken by shrews but the major prey types in all seasons were adult coleopterans, insect larvae, araneids, opilionids and isopods. (3) A mean of 40.8% of prey taken were less than or equal to 5 mm in body length, but very few were smaller than 3 mm. This was correlated with the preponderance of small invertebrates, particularly staphylinids, in the soil/vegetation cores. (4) The diet of S. araneus showed no correlation with the relative activity of prey on the ground surface. (5) There was little correlation between seasonal prey availability and the diet of shrews, but an increase in abundance of adult coleopterans was accompanied by an increase in predation by shrews. (6) The decrease in population density and body weight of shrews in winter was not accompanied by a decrease in biomass or numbers of invertebrate prey.