Unvarying diet of a Neotropical desert marsupial inhabiting a variable environment: the case of Thylamys pallidior

ALBANESE, MS, DACAR MA, OJEDA RA

ACTA THERIOLOGICA

POLISH ACAD SCIENCES

Lugar: Bialowieza; Año: 2012 vol. 87 p. 185 - 188

0001-7051

Studies on the diet and other aspects of the natural history of Neotropical marsupials have focused mainly on a few species from tropical and forest habitats. Research on desert marsupials, on the other hand, is almost absent outside Australia. The desert mouse opossum, Thylamys pallidior, is a small marsupial which inhabits the arid lands of Argentina, Chile, Bolivia, and Peru. In Argentina, it occurs in the Monte desert, a highly seasonal system with a heterogeneous landscape which affords a good opportunity to perform comparisons among different environmental situations. We analyzed fecal samples from 123 individuals and compared their diet among different seasons, habitat types, sexes, and ages. The diet of T. pallidior was composed of 68.7% of arthropods and 31.3% of plant material, mainly leaves (24.6%). We found no significant differences in the proportions of any main food category consumed for any of the factors analyzed. Consumption of both plant and animal material seems to be important in the diet of T. pallidior which manages to keep their proportions constant despite the strong variability and seasonality of the habitat. Contrary to most didelphid species, but similarly to most mammals of this area, leaves seem to represent an important source of food possibly because of their abundance and stability in the Monte desert. This represents the first study to focus on the diet of a Thylamys species inhabiting an arid environment.