Diet of house mice (Mus musculus L.) on coastal sand dunes, Otago, New Zealand

The diet of feral house mice (Mus musculus L.) inhabiting a sand dune ecosy stem near Dunedin, New Zealand, was determined from the contents of 102 sto machs, and quantified in relation to season, gender and reproductive status by fitting linear logistic regression models to frequency of occurrence da ta. Mice were omnivorous, although their diet was biased towards invertebra tes. Overall, 86% of stomachs examined contained plant material, and 90% co ntained invertebrate remains. Lepidopteran larvae (66% of stomachs), Coleop tera (64%, mostly larvae), and Araneae (58%) were important dietary items. Plant material was largely unidentifiable (61%) but included leaves and see ds from three common grass species. Mouse diet varied seasonally, with lepi dopteran larvae and coleopteran larvae eaten significantly more often in su mmer. Reproductive state also influenced diet, at least in summer, when rep roductive females ate Araneae more often than non-reproductive females. Res ults emphasise the importance of invertebrates in the diet of feral house m ice, and the need for more detailed research.