Lagostomus

Abstract: The caging, feeding and handling in our laboratory of 4 unusual hystricomorph rodents are described. These animals are: the wild guinea-pigs, or cuis (Cavia aperea and Galea musteloides), the degu (Octodon degus), and the plains viscacha (Lagostomus maximus). The species were obtained for investigation of their reproduction and some details of this are given.

Abstract: Theoretical models of species coexistence between desert mammals have generally been based on a combination of food and microhabitat selection by granivorous rodents. Although these models are applicable in various deserts of the world, they cannot explain resource use by mammals in Neotropical deserts. The present study examines diet composition in a mammal assemblage in the Monte desert, Argentina. The results show that two main strategies are used by these mammals: medium-sized species (hystricognath rodents: Dolichotis patagonum, Lagostomus maximus, Microcavia australis and Galea musteloides; and an exotic lagomorph: Lepus europaeus) are herbivores, whereas small-sized species (a marsupial: Thylamys pusillus; and sigmodontine rodents: Graomys griseoflavus, Akodon molinae, Calomys musculinus, Eligmodontia typus) are omnivorous. Small mammals also show a tendency towards granivory (C. musculinus), insectivory (A. molinae and T. pusillus) and folivory (G. griseoflavus).

Abstract: Plains viscachas live in communal burrow systems in groups containing one or more males, several females and immatures. Viscachas forage in groups at night and aggregate underground during the day. All members of a group use burrows throughout the communual burrow system and participate in digging at the burrows. Alarm calls are given primarily by adult males. Allogrooming occurs among all sex-age classes within a social group but not between members of different social groups. Agonistic interactions occur more often between members of different social groups than within a group. The long-term social unit of the plains viscacha is the female group. Resident males disappear each year and new males join groups of females. Dominance is absent among females. Agonistic interactions are rare among adult males within a social group and dominance is not clearly evident.