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Rodents are reservoirs of various types of hantavirus, some of which are agents of hantavirus pulmonary syndrome in humans. Each hantavirus is associated with a single rodent host species but successive spill-over events may eventually lead to host-switching and new species' becoming host of a given pathogen. This study aims to gain an understanding of the spatial ecology of two hantavirus-host species, Akodon azarae, and Oligoryzomys flavescens, by identifying factors modulating their home range sizes and stability, and by evaluating intra- and interspecific spatial aggregation for these species and a third one-Oxymycterus rufus-living in sympatry. For this, eleven capture-mark-recapture surveys were carried out, spanning 22 months. We found that A. azarae males have larger and more mobile home ranges than females, independently of the season. Consequently, males could likely have a more relevant role in the transmission of hantavirus because of their greater exposure both to a higher number of contacts between individuals and viral contamination of the environment. Contrasting, O. flavescens individuals showed negligible displacements of their home range through time, which could limit the range of hantavirus spread in host populations. Since O. flavescens is host to Lechiguanas hantavirus (pathogenic to humans) this result encompasses epidemiological relevance, for it may imply the existence of local foci of infection. Additionally, individuals of both species performed excursions outside their home ranges. These events could enable hantavirus spread over distances beyond the normal range of movements and lead to new hantavirus outbreaks in formerly non-infected rodent populations, favoring the persistence of the virus in nature.

Hantavirus pulmonary syndrome is an emerging infectious disease caused by viruses of the genus Orthohantavirus. The rodent Oligoryzomys flavescens is distributed along four countries of South America. In Argentina, O. flavescens acts as a reservoir of three genotypes of ANDV orthohantavirus. The aims of this work were to estimate home range size and movements-with spool-and-line and radiotelemetry-of infected and non-infected O. flavescens in order to understand the spread and transmission of the virus. O. flavescens use a wide area to satisfice its requirements, reaching a home range of 1.82 ha during spring. Orthohantavirus infection did not change the behaviour of individuals. We observed a great overlapping in the home range of infected and non-infected individuals resulting in a high probability of virus dispersion on rodent population. These results show that human health risks could be high on island environments and knowledge about the movement ecology of O. flavescens provides useful information on prevention.

The main objective of this study was to determine the taxonomic and taphonomic characteristics of the micromammal remains recovered from pellets of Pseudoscops clamator (striped owl), collected at three localities in northeastern Buenos Aires Province, Argentina (Punta Lara Natural Reserve, 34°49'02,6''S, 58°03'03,9''W; Costanera Sur Ecological Reserve, 34°36'6,44" S, 58°21'33,22" W; Los Robles Park, 34°40'22,03''S, 58°52'18,88''W). The main taphonomic variables (e.g. evidence of digestive action, breakage patterns and relative abundance of skeletal elements) suggest that this owl mainly produces intermediate to moderate modification. On the other hand, P. clamator preyed mainly upon large-sized (>150 g) micromammals (e.g. Lutreolina crassicaudata, Cavia aperea, Holochilus brasiliensis and Rattus sp.), and to a lesser degree on medium- (50–150 g) and small-sized species (

Gonzalez-Ittig, R. E., Salazar-Bravo, J., Barquez, R. M. & Gardenal, C. N. (2010). Phylogenetic relationships among species of the genus Oligoryzomys (Rodentia, Cricetidae) from Central and South America. —Zoologica Scripta, 39, 511–526. The genus Oligoryzomys includes several species very similar in external morphology, which has resulted in a confusing specific taxonomy. Accurate species identification is particularly important because several species of Oligoryzomys act as natural hosts of hantaviruses affecting humans. Here, we assign specific status to individuals from a wide geographical area of Argentina and Chile using sequences of the mtDNA control region. We also compare cytochrome b sequences of 14 species recognized from Central and South America to infer the phylogenetic relationships within the genus. In addition, the results were analysed using available data on chromosome numbers, and the host–parasite relationships reported for the genus Hantavirus. We confirm the geographical distribution of Oligoryzomys longicaudatus (Argentina, Chile), Oligoryzomys nigripes (Argentina, Paraguay, Brazil), Oligoryzomys chacoensis (Argentina, Bolivia, Paraguay), Oligoryzomys fornesi (Argentina, Paraguay), Oligoryzomys destructor (Argentina, Bolivia) and Oligoryzomys microtis (Bolivia, Brazil). Oligoryzomys longicaudatus is strongly related to the Oligoryzomys flavescens complex, which comprises four clades; O. nigripes is closely related to Oligoryzomys stramineus, and Oligoryzomys vegetus, to Oligoryzomys fulvescens from Central America. Oligoryzomys chacoensis, O. destructor, O. fornesi, O. longicaudatus, O. microtis, O. nigripes, O. stramineus, Oligoryzomys moojeni, Oligoryzomys rupestris, O. fulvescens and O. vegetus are confirmed as valid species, whereas O. flavescens, Oligoryzomys magellanicus, Oligoryzomys griseolus, Oligoryzomys victus, Oligoryzomys andinus and Oligoryzomys arenalis need exhaustive revision. The sister species to all the remaining entities of the genus was O. microtis, suggesting an Amazonian origin for the genus.