Poster presentation 12th International Mammalogical Congress

Influence of ecological factors on burrowing of the specialized red viscacha rat Tympanoctomys barrerae in the Monte desert biome, Mendoza, Argentina (#748)

Andrea Tarquino-Carbonell 1 , Agustina A Ojeda 1 , Ricardo A Ojeda 1
  1. Grupo de Investigaciones de Biodiversidad, Instituto Argentino de Zonas Áridas, CONICET, CCT Mendoza, Mendoza, Argentina

Arid ecosystems represent heterogeneous scenarios in the distribution of resources and species. The red viscacha rat is an octodontid rodent endemic to the aridlands of Argentina. It lives in burrows built on mounds associated with salt basins. The aim of this study is to characterize the associated factors on the burrowing activity of Tympanoctomys barrerae in the Monte desert. We conducted fieldwork in the locality of Huanacache, Mendoza province, from August to January. For the characterization of burrows systems, we measure different ecological data, as orientation and variations of entrances per mound, soil hardness data at 3 and 9 m from burrows, vegetation cover, and biomass. We used live-trapping and radiotelemetry to estimate activity patterns. We found 49 active burrows with a mean distance of 12 m between them. Burrows have length and a maximum height of 4.68 m and 0.45 m; 40% of burrow entrances were facing N and 15% facing E. We find differences in soil hardness at different burrow distances. At a microhabitat level, active burrows were positively associated with vegetative cover (> 53%) and dry biomass (> 24 g). Activity pattern was greater during nighttime than daytime, and the distance moved was around 25 m. These results provide the first microhabitat data associated with the burrowing activity of T. barrerae. The present study highlights the importance of ecological factors (i.e. soil hardness, vegetative cover, and biomass) as drivers for dispersal, colonization and activity patterns of red viscacha rat.