Is habitat selection by the Cabrera vole (Microtus cabrerae) related to food preferences?

The Cabrera vole (Microtus cabrerae) is an Iberian endemism considered threatened both in Portugal and Spain. This vole is often referred to as a tall perennial grassland community specialist. However, a recent study revealed that the Cabrera vole exploits a wide variety of grasslands in south Portugal. The major aim of the present study was to test the palatability of 21 plant species of this region occurring within or outside typical perennial grassland colonies in order to assess vole's food preferences. Results showed a major consumption of monocotyledons and annual plants (such as Festuca ampla, Agrostis castellana, Brachypodium distachyon, B. phoenicoides and Vulpia geniculata), but no relationship was found between diet selection and perennial grassland plant communities. The preference of voles for annual species, occurring more abundantly outside the colonies, raises the hypothesis that the establishment of a colony might be determined by plant species abundance and persistence over the year, rather than by their palatability. This seems to be particularly evident in this region, where summer meteorological conditions make vegetation unavailable outside the colonies.