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

ALBANESE SOLEDAD; DACAR, MARÍA ANA; OJEDA, RICARDO A.

ACTA THERIOLOGICA

POLISH ACAD SCIENCES

Año: 2012 vol. 57 p. 185 - 188

0001-7051

Studies on the diet and other aspects of thenatural history of Neotropical marsupials have focusedmainly on a few species from tropical and forest habitats.Research on desert marsupials, on the other hand, is almostabsent outside Australia. The desert mouse opossum,Thylamys pallidior, is a small marsupial which inhabitsthe arid lands of Argentina, Chile, Bolivia, and Peru. InArgentina, it occurs in the Monte desert, a highly seasonalsystem with a heterogeneous landscape which affords agood opportunity to perform comparisons among differentenvironmental situations. We analyzed fecal samples from123 individuals and compared their diet among differentseasons, 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 nosignificant differences in the proportions of any main foodcategory consumed for any of the factors analyzed.Consumption of both plant and animal material seems tobe important in the diet of T. pallidior which manages tokeep their proportions constant despite the strong variabilityand seasonality of the habitat. Contrary to most didelphidspecies, but similarly to most mammals of this area, leavesseem to represent an important source of food possiblybecause of their abundance and stability in the Montedesert. This represents the first study to focus on the diet ofa Thylamys species inhabiting an arid environment.