Influence of ecological factors on burrowing and activity patterns of the specialized Red Viscacha Rat Tympanoctomys barrerae in the Monte desert biome, Argentina

AGUSTINA A OJEDA; TARQUINO ANDREA; R. A. OJEDA

Perth

Congreso; 12th International Mammalogical Congress; 2017

Australian Mammal Society, International Federation of Mammalogists

Arid ecosystems represent heterogeneous scenarios, mainly determining the distribution of resources and species. Its heterogeneity reflects different scales for variations in topography, climate, precipitation and vegetation. Faced with habitat fragmentation, is necessary inferring which factors affect small mammals dynamics. Red Viscacha Rat is endemic of the Monte and Patagonia ecoregions in Argentina. It lives in burrow systems built on mounds associated with saline environments. The aim of this study is to characterize associated factors on burrowing of Red Viscacha Rat in the Monte desert. We conducted fieldwork in the locality of Huanacache, Mendoza, 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 9m from burrows, vegetation cover and biomass. Finally, we used livetrapping and radiotelemetry to estimate activity patterns and home range. As results, 49 burrows systems were characterized. Mean distance between burrows was 12m. Burrows have length and maxim height of 4.68m and 0.45m. A 40% of burrows entrances was facing N and 15% was facing E. Orientation shows difference in the number of entrances per burrow between quadrants N and S and N and E. We find difference on soil hardness. Mean vegetative cover have 53% per mound. Burrows have a mean biomass of 24g. At microhabitat-level, we found a positive association between vegetative cover, dry biomass and grids with more frequency of active burrow systems. Activity pattern was greater during nighttime than daytime and the distance moved oscillated around of 25m. These results provides many microhabitat data placed together associated to these burrows systems. Present study highlights the importance of considering ecological factors as soil hardness, vegetative cover and biomass for dispersal, colonization and activity patterns of Red Viscacha Rat. Keywords: environmental heterogeneity, home range, Octodontidae, spatial ecology